The distribution of Neuropeptide Y-immunoreactive neurons and nerve fibers in the forebrain of the carp Cyprinus carpio L.

The present study reports the distribution of Neuropeptide Y (NPY)-immunoreactive neurons and fibers in the forebrain of the adult carp Cyprinus carpio L.. Serial Nissl-stained sections were used for cytoarchitecture and identification of anatomical structures. Immunostaining of NPY-containing neurons and fibers was used as neurochemical marker and tool for comparison with other species, including the goldfish.The general outline of the cytoarchitecture of the carp forebrain is similar to that of other Cypriniformes. However, using NPY immunohistochemistry, we found several specific differences with the goldfish, especially in the diencephalon. In the hypothalamus of the carp NPY-immunoreactive (NPYir) neurons were identified in the n. dorsolateralis thalami, and in the n. ventralis lateralis thalami. In the same location, we observed the n. anterior hypothalami and the n. preglomerulosus pars lateralis, described in the goldfish, as parts of n. prerotundus. However, in the carp we were not able to identify a n. preglomerulosus pars medialis, a n. preglomerulosus pars medialis commissuralis and a n. glomerulosus. We describe a n. rotundus, in which we did not find substructures typical of the goldfish.Further differences with the goldfish, trout and salmon were also noted.     

Histochemical mapping of succinic dehydrogenase and cytochrome oxidase in the pons and mesencephalon of squirrel monkey (Saimiri sciureus)

Summary The distribution of succinic dehydrogenase (SDA) and cytochrome oxidase (Cy. O) has been investigated in a series of sections through the pons and mesencephalon of the squirrel monkey brain. The localization of the two enzymes is very similar in the various regions and shows only slight differences. The epiphysis, however, shows moderately strong SDA and very mild Cy. O activity. Particularly strong SDA and Cy. O activity has been observed in the cell bodies of the various cranial nerve nuclei, nucleus colliculi inferioris, colliculi superioris, nuclei griseum pontis, reticularis tegmenti pontis, lemnisci lateralis pars dorsalis, geniculatum laterale and mediale, and pulvinaris. The enzyme content of the neurons and cell bodies is generally stronger compared to the neuropil which often occurs in smooth, loose, compact and reticulated forms. Any special relationship between the neurons and neuropil with regard to their enzyme content has, however, not been observed. The cranial nerves, and fibers of the brachium conjunctivum, corpus callosum, and fornix show very mild enzyme activity except those of the trapezoid complex which show moderate enzyme activity.Abbreviations Ann Nucleus annularis - APT Area praetectalis - AS Aquaeductus Sylvii - BC Brachium conjunctivum - BCI Brachium colliculi inferioris - BCS Brachium colliouli superioris - BP Brachium pontis - Cb Cerebellum - CC Corpus callosum - CCI Commissura colliculi inferioris - CCS Commissura colliculi superioris - Cd Nucleus caudatus - CHD Commissura hippocampi —parsdorsalis - CoI Colliculus inferior - CoP Commissura posterior - CoR Corona radiata - CoS Colliculus superior - CPf Cortex piriformis - CR Cortex retrosplenialis - DBC Decussatio brachii conjunctivi - DG Nucleus dorsalis tegmentalis(Gudden) - DR Nucleus dorsalis raphes - EP Epiphysis - F Fornix - FH Fimbria hippocampi - FLM Fasciculus longitudinalis medialis - FRPC Formatio reticularis pontis, parscaudalis - FRPO Formatio reticularis pontis, parsoralis - FRTM Formatio reticularis tegmentimesencephali - GC Substantia grisea centralis - GCd Substantia grisea centralis, parsdorsalis - GCv Substantia grisea centralis, parsventralis - GL Corpus geniculatum laterale - GM Corpus geniculatum mediate - GPO Griseum pontis - Hipp Hippocampus - HL Nucleus habenulae lateralis - HM Nucleus habenulae medialis - IP Nucleus interpeduncularis - LC Nucleus locus coeruleus - LCb Lingula cerebelli - Lim Nucleus limitans thalami - LL Lemniscus lateralis - LLD Nucleus lemnisci lateralis —parsdorsalis - LM Lemniscus medialis - LP Nucleus lateralis posterior thalami - MD Nucleus medialis dorsalis thalami - Mv Nucleus motorius n. trigemini - NCI Nucleus colliculi inferioris - NCS Nucleus centralis superior tegmenti - NCT Nucleus trapezoideum - NMv Nucleus tractus mesencephalicus n.trigemini - NR Nucleus ruber - NST Nucleus supratrochlearis - NSv Nucleus tractus spinalis n. trigemini - NiiiC Nucleus centralis n. oculomotorii - NiiiD Nucleus n. oculomotorii — pars dor-salis - NiiiV Nucleus n. oculomotorii — pars ven-tralis - Niv Nucleus n. troehlearis - nvm Nervus trigeminus, portio major - niv Nervus trochlearis - nvi Nervus abducens - OS Nucleus olivaris superior - P Nucleus posterior thalami - PbL Nucleus parabrachialis lateralis - PbM Nucleus parabrachialis medialis - PC Pedunculus cerebri - Pg Nucleus parabigeminalis - PUI Nucleus pulvinaris inferior thalami - PUL Nucleus pulvinaris lateralis thalami - PUM Nucleus pulvinaris medialis thalami - Py Tractus pyramidalis - Pv Nucleus principalis n. trigemini - R Nucleus reticularis thalami - RTP Nucleus reticularis tegmenti pontis - SNc Substantia nigra — pars compacta - SNd Substantia nigra — pars diffusa - Sub Subiculum - TCT Tractus corticotectalis - VR Nucleus ventralis raphes - III Ventriculus tertius - IV Ventriculus quartus     

Anatomical distribution of NPY‐like immunoreactivity in the domestic chick brain (Gallus domesticus)

Neuropeptide Y‐immunoreactive (NPY‐ir) fibers and neurons in the brain of the domestic chick (Gallus domesticus) were described using an immunohistochemical technique. NPY‐ir neurons were seen in the lobus parolfactorius; hyperstriatum, neostriatum, paleostriatum, and archistriatum; hippocampal and parahippocampal areas; dorsolateral corticoid area; piriform cortex; two thalamic areas contiguous to the n. rotundus; n. dorsolateralis anterior thalami, pars lateralis, and pars magnocellularis; n. periventricularis hypothalami; n. paraventricularis magnocellularis; regio lateralis hypothalami; n. infundibuli; inner zone of the median eminence; dorsal and lateral portions of the n. opticus basalis; n. raphes; and n. reticularis paramedianus. NPY‐ir fibers were seen throughout the entire chick brain, but were more abundant in the hypothalamus where they formed networks and pathways. They were also observed in some circumventricular organs. The anatomical data of the present study regarding the distribution of NPY ir in the chick brain, together with the physiological findings of other studies, suggest that NPY plays a key role in the regulation of the neuroendocrine, vegetative, and sensory systems of birds by acting as a neuromodulator and/or neurotransmitter. Anat Rec 263:186–201, 2001. © 2001 Wiley‐Liss, Inc.     

Anatomical distribution of NPY-like immunoreactivity in the domestic chick brain (Gallus domesticus)

Neuropeptide Y-immunoreactive (NPY-ir) fibers and neurons in the brain of the domestic chick (Gallus domesticus) were described using an immunohistochemical technique. NPY-ir neurons were seen in the lobus parolfactorius; hyperstriatum, neostriatum, paleostriatum, and archistriatum; hippocampal and parahippocampal areas; dorsolateral corticoid area; piriform cortex; two thalamic areas contiguous to the n. rotundus; n. dorsolateralis anterior thalami, pars lateralis, and pars magnocellularis; n. periventricularis hypothalami; n. paraventricularis magnocellularis; regio lateralis hypothalami; n. infundibuli; inner zone of the median eminence; dorsal and lateral portions of the n. opticus basalis; n. raphes; and n. reticularis paramedianus. NPY-ir fibers were seen throughout the entire chick brain, but were more abundant in the hypothalamus where they formed networks and pathways. They were also observed in some circumventricular organs. The anatomical data of the present study regarding the distribution of NPY ir in the chick brain, together with the physiological findings of other studies, suggest that NPY plays a key role in the regulation of the neuroendocrine, vegetative, and sensory systems of birds by acting as a neuromodulator and/or neurotransmitter.     

Distribution of serotonin-immunoreactivity in the central nervous system of the rat—Cell bodies and terminals

The localization and distribution of serotonin (5-hydroxytryptamine, 5-HT) has been studied with the indirect immunofluorescence technique using a highly specific and well-characterized antibody to 5-HT. In neuron systems 5-HT was found to be primarily present with a distribution similar to that observed in basic mappings carried out with the formaldehyde-induced fluorescence method. In addition to the nine areas originally described, several other areas in the mesencephalon and rhombencephalon appeared to contain widely distributed 5-HT-positive perikarya. In the median eminence 5-HT fluorescent mast cells could be visualized. No 5-HT-positive nerve cell bodies could be observed either in the telencephalon or diencephalon.Our results also demonstrate a widespread occurrence of 5-HT-positive nerve terminals throughout the central nervous system. Dense populations of serotonin-immunoreactive nerve terminals are present in the following areas, from rostral to caudal: various parts of the medial forebrain bundle; the ventromedial part of the nucleus suprachiasmaticus: the most ventrolateral part of the caudatus-putamen complex; an area between the rostral part of the nucleus reuniens and the fornix: at that same level of the latter area, a region just ventral of the fornix; the dorsolateral part of the nucleus periventricularis thalami; an area lateral of the claustrum, close to the cortex piriformis; the nucleus amygdaloideus basalis; the dorsomedial part of the nucleus medialis thalami pars medialis, only in the rostral part; the inner part of the nucleus ventromedialis hypothalami; the ventral part of the nucleus mamillaris medialis; the radiatio thalami superior; the nucleus subthalamicus; the caudal part of the nucleus amygdaloideus medialis posterior; the area pretectalis radialis; the dorsal part of the nucleus ventralis corporis geniculati lateralis; the ventromedial part of the substantia nigra reticularis; an area ventral of the decussatio supramammillaris; the substantia nigra pars lateralis; the dorsolateral part of the nucleus reticularis pontis oralis; some parts of the nucleus origines nervi trigemini; the ventromedial part of the nucleus origines nervi facialis; the medial part of the nucleus tractus solitarius and the medial part of the cornu ventrale of the spinal cord. There are only a few areas where no serotonin-immunoreactivity could be found. Within several areas, as, e.g., hippocampus, nucleus caudatus, medial forebrain bundle, the density of serotoninergic fibers appeared to show considerable local differences. Within the same nuclei or area the amount can differ considerably.This immunohistochemical procedure makes it possible to study the distribution of serotonin-containing nerves and their processes in considerable detail. The finding that serotonin-containing neurons are present in many nuclei that also include catecholamine-containing neurons makes it necessary to reconsider the terminology of the monoaminergic cell groups.     

An immunocytochemical mapping of ACTH/CLIP in the cat diencephalon

Using an indirect immunoperoxidase technique, the location of cell bodies and fibres containing adrenocorticotropin hormone/corticotropin-like intermediate lobe peptide (ACTH/CLIP) was studied in the cat diencephalon. Immunoreactivity was observed in several diencephalic nuclei of the cat in which no immunoreactivity has been previously reported. In this sense, a low density of immunoreactive cell bodies was found in the nucleus ventromedialis hypothalami; a high density of immunoreactive fibres was found in the medial preoptic area; a moderate density in the lateral preoptic area and in the nuclei centralis thalami (pars medialis), interventralis thalami, interanteromedialis thalami, parafascicularis and praemamillaris (pars ventralis and pars dorsalis); a low density in the nuclei habenularis lateralis and reuniens thalami, and single fibres were found in the nuclei lateralis thalami (pars anterior), habenularis medialis, parataenialis, corpus geniculatum mediale, ventralis thalami (pars medialis) and in the fornix. Our results point to a more widespread distribution of ACTH/CLIP immunoreactive structures in the cat diencephalon in comparison with previous studies carried out in the same region of this feline.     

Autoradiographic localization of receptors for neuropeptide Y (NPY) in the brain of broiler and leghorn chickens (Gallus domesticus)

Broiler and leghorn chickens show an extreme difference in ingestive and reproductive behavior. As neuropeptide Y (NPY) influences both behaviors the goal of this study was to elucidate the distribution, expression and affinity of NPY binding sites in broiler and leghorn chicken brain. By means of in vitro autoradiography, sections of chicken brains were incubated with ³H-NPY as tracer and NPY as displacer. Scatchard analysis revealed a curvilinear plot suggesting two subtypes of the NPY binding site in the chicken brain, a high affinity one (K_D = 2–4 nM) and one with a lower affinity (K_D = 18–24 nM). Binding sites for NPY are localized with high density in the different subdivisions of the neostriatum and the hyperstriatum, the cerebellum, the nucleus septalis lateralis and medialis, the nucleus ruber and the nucleus tractus solitarii. A lower density of NPY binding sites was found in the different subdivisions of the striatum, the nucleus mesencephalicus lateralis pars dorsalis, the paleostriatum, the archistriatum intermedium pars ventralis, the nucleus geniculatus lateralis, the nucleus taeniae, the locus ceruleus, the nucleus rotondus, the nucleus habenularis medialis, the nucleus dorsomedialis anterior (rostralis) thalami, the pituitary and the area of the hypothalamus with its nuclei such as the nucleus paraventricularis magnocellularis and the nucleus preopticus medialis. Comparison of the localization of NPY binding sites in the brains of broilers and leghorns showed no differences but the density of both receptor types is two to three times higher in broilers than in leghorns.     

Projections from the primary somatosensory cortex to basal ganglia and thalamus in the monkey

Summary Radioactive amino acids were injected into the postcentral cortex (areas 3, 1 and 2) in 6 monkeys (Macaca fascicularis). Fibers were traced to the ipsilateral putamen, to Olszewski's n. ventralis posterior lateralis pars caudalis, n. ventralis posterior medialis and inferior, to n. pulvinaris oralis, n. suprageniculatus and corpus geniculatum mediale pars magnocellularis. Furthermore, there were faint postcentral projections to claustrum, n. caudatus, n. centralis lateralis, n. centrum medianum, zona incerta and with respect to the postcentral face region to n.medialis dorsalis pars multiformis.Discrepancies with earlier findings were discussed and comparison was made between pre- and postcentral target regions.Abbreviations Cd n. caudatus - ci capsula interna - CL n. centralis lateralis - Cl claustrum - CM n. centrum medianum - GL corpus geniculatum laterale - GM corpus geniculatum mediale - GMpc corpus geniculatum mediale pars parvocellularis - GMmc corpus geniculatum mediale pars magnocellularis - GP globus pallidus - la sulcus lateralis - LP n. lateralis posterior - MD n. medialis dorsalis - OI opercular-insular cortex - Pen n. paracentralis - Pf n. parafascicularis - PI n. pulvinaris inferior - PO n. pulvinaris oralis - Pu putamen - RT n. reticularis thalami - SG n. suprageniculatus - SN substantia nigra - St n. subthalamicus - thi tractus habenulo-interpeduncularis - tmt tractus mammillo-thalamicus - to tractus opticus - VA n. ventralis anterior - VLc n. ventralis lateralis, p. caudalis - VLo n. ventralis lateralis, p. oralis - VPI n. ventralis posterior inferior - VPL n. ventralis posterior lateralis - VPLc n. ventralis posterior lateralis p. caudalis - VPLo n. ventralis posterior lateralis p. oralis - VPM n. ventralis posterior medialis - ZI zona incerta     

Electrophysiological investigation of the archistriato-hypothalamic pathway in the pigeon (Columba livia)

The connection from the limbic part of the avian archistriatum (Am+Ap) to the hypothalamus by way of the tractus occipito-mesencephalicus, pars hypothalami (HOM) was investigated electrophysiologically by means of electrical stimulation in the archistriatum and extracellular single unit recording in the hypothalamus. A powerful activating influence of Am on the hypothalamus could be demonstrated, which involved not only the established termination region of HOM in the posterior hypothalamus, but also the lateral and anterior hypothalamus, the stratum cellulare internum (SCI) and externum (SCE). The response patterns in the medial region differ in a characteristic manner from those in the lateral and posterior regions. Whereas neurons in the medial hypothalamus have small amplitudes (0.2 mV) and are evoked with relatively long latencies (>8 ms), responses in the remaining regions appear to have higher amplitudes (up to 1 mV) and faster conduction velocities.The results are not in conflict with the presence of the postulated [25] direct anatomical pathway, but monosynaptic transmission was proven neither for the projection to the medial nor for that to the lateral region. The spontaneous activity of some neurons in LHy, SCI and SCE was inhibited by Am stimulation. It is concluded that the HOM-tract includes several pathways mediating slow and fast, monosynaptic and polysynaptic excitatory and inhibitory effects. These observations on the archistriato-hypothalamic connections in the pigeon compare with those on amygdalo-hypothalamic projections via stria terminalis in the rat and contrast with the more complex organization of these pathways encountered in higher mammals.Abbreviations Aa Archistriatum anterior - AHM Nucleus anterior medialis hypothalami - Ai Archistriatum intermedium - Aid Archistriatum intermedium, pars dorsalis - AL Ansa lenticularis - Am Archistriatum mediale - Ap Archistriatum posterior - CO Chiasma opticum - CoS Nucleus commissuralis septi - DA Tractus archistriatalis dorsalis - DIP Nucleus dorsointermedius posterior thalami - DLL Nucleus dorsolateralis anterior thalami. pars lateralis - DLM Nucleus dorsolateralis anterior thalami. pars medialis - DLP Nucleus dorsolateralis posterior thalami - DMA Nucleus dorsomedialis anterior thalami - DMP Nucleus dorsomedialis posterior - TA Tractus-frontoarchistriatalis - FPL Fasciculus prosencephali lateralis - GLv Nucleus geniculatus lateralis, pars ventralis - HOM Tractus occipitomesencephalicus, pars hypothalami - IPS Nucleus interstitio-pretecto-subpretectalis - LA Nucleus lateralis anterior thalami - LHy Hypothalamus lateralis - nST Nucleus striae terminalis - OM Tractus occipitomesencephalicus - Ov Nucleus ovoidalis - PA Paleostriatum augmentatum - pB Commissura anterior, pars bulbaris - PP Paleostriatum primitivum - PPc Nucleus principalis precommissuralis - PVM Nucleus periventricularis magnocellularis - QF Tractus quintofrontalis - Rt Nucleus rotundus - SCE Stratum cellulare externum - SCI Stratum cellulare internum - SL Nucleus septalis lateralis - SM Nucleus septalis medialis - SP Nucleus subpretectalis - SPC Nucleus superficialis parvocellularis - SPM Nucleus spiriformis lateralis - SRt Nucleus subrotundus - T Nucleus triangularis - TIO Tractus isthmo-opticus - Tn Nucleus taeniae - TOv Tractus nuclei ovoidalis - TrO Tractus opticus - TSM Tractus septomesencephalicus - TT Tractus tectothalamicus - TU Nucleus tuberis - V Ventriculus     

Origin of leucine-enkephalin fibers and their two main afferent pathways in the bed nucleus of the stria terminalis in the rat

Summary The destruction of th central amygdaloid nucleus (Ce), which contains a large group of neurons with leucine-enkephalin (L-ENK)-like immunoreactivity (L-ENKI), resulted in a marked ipsilateral reduction of these fibers in the bed nucleus of the stria terminalis (BST) suggesting that L-ENKI neurons in the Ce project ipsilaterally to the BST. This was supported by the finding that injection of biotin-wheat germ agglutinin into the BST labeled many neurons in the Ce. Simultaneous staining with antiserum showed that some of these neurons are L-ENKI. The L-ENKI fibers from the Ce reach the BST via two pathways; one from the ventral amygdalofugal pathway (VA), which terminate in the ventral subdivision of the BST pars lateralis (BSTL), and the other from the stria terminalis (ST), which terminates in the lateral subdivision of the BSTL, because (1) accumulation of L-ENKI structures appeared in the axons of these two systems on the amygdaloid side, (2) transection or destruction of the ST alone caused only a slight reduction of ENKI fibers in the lateral subdivision of the BSTL ipsilaterally and (3) transection or destruction of VA alone markedly reduced the number of L-ENKI fibers in the ventral subdivision of the ipsilateral BSTL. Thus, the VA L-ENKI fiber system is the major source of L-ENKI fibers in the ventral subdivision, while the ST L-ENKI fiber system is a minor source of the L-ENKI fibers in the lateral subdivision. The presence of an intrinsic L-ENKI system in the BST which may innervate the lateral subdivision was also suggested.Abbreviations used in Figures ac anterior commissure - AHy anterior hypothalamic nucleus - AM anteromedial thalamic nucleus - AV anteroventral thalamic nucleus - BST bed nucleus of stria terminalis - BSTL BST pars lateralis - BSTM BST pars medialis - Ce central amygdaloid nucleus - f fornix - GP globus pallidus - HDB horizontal limb of diagonal band of Broca - ic internal capsule - l lateral subdivision of the BSTL - LH lateral hypothalamus - LPO lateral preoptic area - LS lateral septal nucleus - m medial subdivision of the BSTL - Mfb medial forebrain bundle - MPO medial preoptic area - MS medial septal nucleus - ox optic chiasma - Re reuniens thalamic nucleus - Rt reticular thalamic nucleus - SI substantia innominata - sm stria medularis thalami - st stria terminalis - v ventral subdivision of the BSTL - va ventral amygdalofugal pathway - VDB vertical limb of diagonal band of Broca - VP ventral pallium - 2n optic nerve - 3v third ventricle     

The distribution of zinc in the forebrain and midbrain of the lizard Gekko gecko

Summary The distribution of zinc in the forebrain and midbrain of the lizard Gekko gecko was studied with the recently modified Timm method. Areas with a high intensity of staining are almost exclusively found in the telencephalon, although also some structures in the diencephalon display notable staining. Cortical areas that stain heavily are the deep zone of the subcortical layer of the small-celled medial cortex, the longitudinal association bundle that encompasses the large-celled medial cortex, and the dorsal cortex. Of the subcortical areas, particularly the anterior septal nucleus shows a high intensity of staining. Moderate to dense Timm staining is further observed in the ventral part of the anterior lateral cortex, the lateral septal nucleus, the striatum, the amygdaloid complex, and the dorsal ventricular ridge. Staining in the diencephalon is primarily confined to the stria terminalis and the ventromedial hypothalamic nucleus, whereas in the midbrain weak staining is observed in the ventral tegmental area and the periventricular layers of the tectum and the tegmentum. The presence of zinc in the gekkonid brain is discussed in relation to connections and neurotransmitters as studied in the same species. Moreover, similarities in pattern of staining for zinc in mammals and reptiles and possible evolutionary implications are mentioned.Abbreviations Acc nucleus accumbens - Alh area lateralis hypothalami - Amc nucleus centralis amygdalae - Ame nucleus externus amygdalae - Aml nucleus lateralis amygdalae - Anm nucleus marginalis amygdalae - Bmfb bed nucleus of the medial forebrain bundle - Cgld corpus geniculatum laterale pars dorsalis - Cglv corpus geniculatum laterale, pars ventralis - Cgp corpus geniculatum pretectale - cpa commissura pallii anterior - cso commissura supraoptica - Cxd cortex dorsalis - Cxla cortex lateralis, pars anterior - Cxlp cortex lateralis, pars posterior - Cxml cortex medialis, large-celled part - Cxms cortex medialis, small-celled part - Dlh nucleus dorsolateralis hypothalami - Dll nucleus dorsolateralis thalami, large-celled part - Dls nucleus dorsolateralis thalami, small-celled part - Dm nucleus dorsomedialis thalami - DVR dorsal ventricular ridge - Ent nucleus entopeduncularis - Hab ganglion habenulae - lfb lateral forebrain bundle - lfbv lateral forebrain bundle, ventral peduncle - Lte nucleus lentiformis thalami, pars extensa - Ltp nucleus lentiformis thalami, pars plicata - Mp nucleus medialis posterior - Mt nucleus medialis thalami - NdB nucleus of the diagonal band of Broca - Nsa nucleus septalis anterior - Nsd nucleus septalis dorsalis - Nsl nucleus septalis lateralis - Nsm nucleus septalis medialis - Nsph nucleus sphericus - oph organon periventriculare hypothalami - Ph nucleus periventricularis hypothalami - Ppo periventricular preoptic area - Rot nucleus rotundus - Rub nucleus ruber - Sped nucleus suprapeduncularis - st stria terminalis - Str striatum - tect tectum - topt tractus opticus - Torc nucleus centralis of the torus semicircularis - Torl nucleus laminaris of the torus semicircularis - tsh tractus septohypothalamicus - Vltv nucleus ventrolateralis thalami, pars ventralis - Vmh nucleus ventromedialis hypothalami - Vmt nucleus ventromedialis thalami - VTA ventral tegmental area - III nucleus nervi oculomotorii     

Topographic organization of the projection from the forebrain subcortical areas to the hippocampal formation of the rat

Using the technique of iontophoretic microinjection of horseradish peroxidase, the present study disclosed the complexity and high degree of the topographic organization in the forebrain subcortical afferents to the different regions of rat hippocampus, e.g. diagonal band, posterior (PH), dorsomedial and rostral lateral hypothalamic nuclei chiefly project to the rostrodorsal part (DRA) and caudal gyrus dentatus including CA3, the supramammillary area predominantly to the rostroventral area (VRA), the area lateral to PH to the DRA and VRA, substantia innominata and some thalamic nuclei (n. reuniens, n. lateralis thalami, n. anterior ventralis thalami and n. lateralis thalami pars posterior) to the dorsal subiculum, respectively.     

Cytoarchitecture of the substantia nigra in the rat

Midbrains of ten young adult rats were sectioned serially in three planes to study the detailed cytoarchitecture of the substantia nigra. These neurons measure 8 to 17 μ in diameter. In comparison, the largest neurons in the midbrain measure 20 to 40 μ; hence, neurons are designated according to size as follows: those measuring 18 to 40 μ, large; 12 to 17 μ, medium; and 8 to 11 μ, small. The substantia nigra of the rat contains non-pigmented neurons in three divisions: pars reticulata, pars compacta, and pars lateralis. The pars reticulata is the largest division and has the longest rostrocaudal extent. It contains neurons of small size medially and of medium size laterally. This finding correlates with described differences in connections. Three-dimensionally, the pars reticulata is an oblate spheroid with the long axis in the rostrocaudal plane. The pars compacta is a triangular layer dorsal to reticulata. It is subdivided into rostral and caudal portions at the level of the fibers of the basal optic root. Neurons in both subdivisions are medium in size, but cells rostrally are darker than those caudally. The pars lateralis is a column of neurons with its long axis located in the rostrocaudal plane. It lies dorsolateral to the pars reticulata and the pars compacta, with occasional connections to both by cellular strands. The pars lateralis has rostral and caudal portions; neurons rostrally are medium in size and round; caudally, however, neurons are variable in size, dark, stellate or fusiform, and have long processes.     

Brain stimulation-induced changes of phonation in the squirrel monkey

Summary In 11 squirrel monkeys (Saimiri sciureus), the brain stem was systematically explored with electrical brain stimulation for sites affecting the acoustic structure of ongoing vocalization. Vocalization was elicited by electrical stimulation of different brain structures. A severe deterioration of the acoustical structure of vocalization was obtained during stimulation of the caudoventral part of the periaqueductal grey, lateral parabrachial area, corticobulbar tract, nucl. ambiguus and surrounding reticular formation, facial nucleus, hypoglossal nucleus, solitary tract nucleus and along the fibres crossing the midline at the level of the hypoglossal nucleus. It is suggested that these structures are part of, or at least have direct access to, the motor coordination mechanism of phonation. Complete inhibition of phonation was obtained from the raphe and raphe-near reticular formation.Abbreviations Ab nucl ambiguus - APt area praetectalis - BC brachium conjunctivum - BP brachium pontis - Cb cerebellum - CC corpus callosum - Cd nucl. caudatus - Cf nucl. cuneiformis - Cel nucl. centralis lateralis - Cl claustrum - CM centrum medianum - Cn nucl. cuneatus - Co nucl. cochlearis - CoI colliculus inferior - CoS colliculus superior - CP commissura posterior - CPf cortex piriformis - CRf corpus restiforme - CSL nucl. centralis superior lateralis thalami - CT corpus trapezoideum - DBC decussatio brachii conjunctivi - DG nucl. dorsalis tegmenti (Gudden) - DLM decussatio lemnisci medialis - DPy decussatio pyramidum - DR nucl. dorsalis raphae - DV nucl. dorsalis n. vagi - DIV decussatio n. trochlearis - EP epiphysis - FC funiculus cuneatus - FL funiculus lateralis - FLM fasciculus longitudinalis medialis - FRM formatio reticularis myelencephali - FRP formatio reticularis pontis - FRPc formatio reticularis pontis caudalis - FRPo formatio reticularis pontis oralis - FRTM formatio reticularis mesencephali - FV funiculus ventralis - G nucl. gracilis - GC substantia grisea centralis (periaqueductal grey) - GL nucl. geniculatus lateralis - GM nucl. geniculatus medialis - GP globus pallidus - GPM griseum periventriculare mesencephali - GPo griseum pontis - Hip hippocampus - HL nucl. habenularis lateralis - H habenula - IP nucl. interpeduncularis - LC locus coeruleus - LD nucl. lateralis dorsalis thalami - Lim nucl. limitans - LLd nucl. lemnisci lateralis, pars dorsalis - LLv nucl. lemnisci lateralis, pars ventrali - LM lemniscus medialis - LP nucl. lateralis posterior thalami - MD nucl. medialis dorsalis thalami - MV nucl. motorius n. trigemini - NCS nucl. centralis superior - NCT nucl. trapezoidalis - NMV nucl. mesencephalicus n. trigemini - NR nucl. ruber - NSV nucl. spinalisn. trigemini - NTS nucl. tractus solitarii - NIII nucl. oculomotorius - NIV nucl. trochlearis - NVI nucl. abducens - NVII nucl. facialis - NXII nucl. hypoglossus - OI oliva inferior - OS oliva superior - P nucl. posterior thalami - PbL nucl. parabrachialis lateralis - PbM nucl. parabrachialis medialis - PC depedunculus cerebri - Pd nucl. peripeduncularis - Pg nucl. parabigeminalis - Pp nucl. praepositus - PuI nucl. pulvinaris inferior - PuL nucl. pulvinaris lateralis - PuM nucl. pulvinaris medialis - PuO nucl. pulvinaris oralis - Py tractus pyramidalis - Pv nucl. principalis n. trigemini - R Ab nucl. retroambiguus - RL nucl. reticularis lateralis - RTP nucl. reticularis tegmenti pontis - Sf nucl. subfascicularis - SGD substantia grisea dorsalis - SGV substantia grisea ventralis - SN substantia nigra - ST stria terminalis - St subthalamus - TRM tractus retroflexus (Meynert) - TSc tractus spinocerebellaris - Ves nucl. vestibularis - VL nucl. ventralis lateralis - VPI nucl. ventralis posterior inferior - VPL nucl. ventralis posterior lateralis - VPM nucl. ventralis posterior medialis - VR nucl. ventralis raphae - Zi zona incerta - II tractus opticus - VII n. facialis     

Ascending and descending components of the medial forebrain bundle in the rat as demonstrated by the horseradish peroxidase-blue reaction

Summary The ascending and descending components of the medial forebrain bundle (MFB) were investigated by means of horseradish peroxidase (HRP) with a sensitive substrate. The HRP was injected iontophoretically into the MFB at various levels from the anterior commissure to the posterior hypothalamus. In order to prevent the diffusion of HRP to other brain areas, a double micropipette system was used. The descending components of the MFB are derived from (1) the anterior cingulate area, infra- or prelimbic area, and sulcal cortex, (2) the lateral septal nucleus and diagonal band, (3) the bed nucleus of the stria terminalis, (4) the paraventricular nucleus (5) the substantia innominata, (6) the amygdaloid complex (AM), (7) the ventromedial (VM) and dorsomedial (DM) hypothalamic nuclei, (8) the entopeduncular nucleus and (9) nucleus periventricularis stellatocellularis. The ascending components of the MFB originate in: (1) the medial preoptic nucleus, (2) the nucleus periventricularis stellatocellularis and rotundocellularis, (3) the posterior hypothalamic nucleus, (4) the parafascicular nucleus, (5) the ventral premammillary nucleus, (6) the substantia grisea periventricularis, (7) the lateral habenular nucleus, (8) the VM and DM, (9) the paratenial nucleus, (10) the AM and (11) the arcuate nucleus.Abbreviations used in Figures and Tables a nucleus accumbens - abl nucleus amygdaloideus basalis, pars lateralis - abm nucleus amygdaloideus basalis, pars medialis - ac nucleus amygdaloideus centralis - AC anterior cingulate area - al nucleus amygdaloideus lateralis - am nucleus amygdaloideus medialis - ar nucleus arcuatus - CC tractus corporis callosi - CSDV commissura supraoptica dorsalis, pars ventralis - DB diagonal band - DM nucleus dorsomedialis hypothalami - EP nucleus entopeduncularis - ha nucleus anterior hypothalami - hl nucleus lateralis hypothalami - hp nucleus posterior hypothalami - IL infralimbic area of frontal cortex - lh nucleus habenulae lateralis - LH₁ medial forebrain bundle (MFB) at the level of commissura anterior - LH₂ lateral preoptic area - LH₃ MFB at the level of the nucleus anterior hypothalami - LH₄ MFB at the level of the nucleus ventromedialis hypothalami - LH₅ MFB at the level of the nucleus posterior hypothalami - MFB medial forebrain bundle - pf nucleus parafascicularis - PL prelimbic area of frontal cortex - pol nucleus preopticus lateralis - pom nucleus preopticus medialis - posc nucleus preopticus, pars suprachiasmatica - pt nucleus parataenialis - pv nucleus premamillaris ventralis - PV nucleus paraventricularis - pvs nucleus periventricularis stellatocellularis - pvr nucleus periventricularis rotundocellularis - SC sulcal cortex - SGPV substantia grisea periventricularis - SI substantia innominata - SL lateral septal nucleus - ST bed nucleus of stria terminalis - sum nucleus supramamillaris - TO tractus opticus - tmm nucleus medialis thalami, pars medialis - VM nucleus ventromedialis hypothalami The nomenclature used in this paper is according to König and Klippel's Stereotaxic Atlas (1967).     

The primary visual system of flatfish: an evolutionary perspective

Summary The retinal projections of two species of flatfish (Scophthalmus maximus, Scophthalmidae; Platichthys flesus, Pleuronectidae) were investigated by autoradiography and by a HRP technique. Contralateral projections to five hypothalamic centres (area optica preoptica ventralis, nucleus opticus preopticus parvocellularis posterior pars lateralis, n. suprachiasmaticus, n. opticus hypothalami ventromedialis and area optica hypothalami posterior), thirteen thalamo-pretectal centres (nucleus opticus dorsolateralis (partes medialis, ventralis and lateralis), n. opticus ventrolateralis, n. opticus commissurae posterioris (partes dorsalis and ventralis), n. opticus accessorius, n. geniculatus lateralis mesencephali, nn. opticus pretectalis dorsalis, medialis and ventralis and n. corticalis), three layers of the optic tectum (stratum opticum pars externa, stratum fibrosum et griseum superficiale, stratum album centrale), and a single target in the tegmentum (n. opticus tegmenti mesencephali dorsalis), were identified in both species. Interspecific variation of the contralateral visual projections is relatively small. Ipsilateral visual projections of fibres which recross the midline in the minor and transverse commissures were also identified; in S. maximus this ipsilateral contingent is poorly developed and concerns principally hypothalamic structures, while in P. flesus the ipsilateral projections are considerably more extensive and involve both hypothalamic and thalamo-pretectal primary visual centres. No differences in the projections from the fixed and from the migrated eye were observed in either species. The findings are discussed in the general context of the existing literature on the visual projections of teleosts, in an attempt to characterize the primary visual system of the Pleuronectiformes in an evolutionary context.List of Abbreviations AOHp Area optica hypothalami posterior - AOPv Area optica preoptica ventralis - CER Cerebellum - Com. H Commissura horizontalis - Com. M Commissura minor - Com. T Commissura transversalis - Cp Commissura posterioris - FDtro Fasciculus dorsalis tractus optici - FHtro Fasciculus hypothalami tractus optici - FOCM Fasciculus opticus commissurae minor - FOCT Fasciculus opticus commissurae transversalis - FOHpv Fasciculus opticus hypothalami posterior pars ventralis - FVLtro Fasciculus ventrolateralis tractus optici - FVLtroi Fasciculus ventrolateralis optici ipsilateralis - FVMtro Fasciculus ventromedialis tractus optici - FVMtroi Fasciculus ventromedialis tractus optici ipsilateralis - FVtro Fasciculus ventralis tractus optici - Hyp Hypophysis cerebri - IS Interlobular sulcus - LO Lobus opticus - LOd Lobus opticus dorsalis - LOv Lobus opticus ventralis - LON left optic nerve - NC Nucleus corticalis - NDLi Nucleus diffusus lobi inferioris - NDM Nucleus dorsomedialis - NE Nucleus entopeduncularis - NG Nucleus glomerulosus - NGL Nucleus geniculatus lateralis - NGLM Nucleus geniculatus lateralis mesencephali - NOA Nucleus opticus accessorius - NOCPpd Nucleus opticus commissurae posterions pars dorsalis - NOCPpv Nucleus opticus commissurae posterioris pars ventralis - NODL Nucleus opticus dorsolateralis - NODLpl Nucleus opticus dorsolateralis pars lateralis - NODLpm Nucleus opticus dorsolateralis pars medialis - NODLpv Nucleus opticus dorsolateralis pars ventralis - NOHvl Nucleus opticus hypothalamicus ventrolateralis - NOPd Nucleus opticus pretectalis dorsalis - NOPL Nucleus opticus pretectalis lateralis - NOPm Nucleus opticus pretectalis medialis - NOPPpl Nucleus opticus preopticus parvocellularis posterior pars lateralis - NOPv Nucleus opticus pretectalis ventralis - NOTMd Nucleus opticus tegmenti mesencephali dorsalis - NOTMdl Nucleus opticus tegmenti mesencephali dorsalis pars lateralis - NOTMdm Nucleus opticus tegmenti mesencephali dorsalis pars medialis - NOVL Nucleus opticus ventrolateralis - NPG Nucleus preglomerulosus - NPMg Nucleus preopticus magnocellularis - NPP Nucleus preopticus parvocellularis posterior - NPPa Nucleus preopticus parvocellularis anterior - NPs Nucleus pretectalis superficialis - NRL Nucleus recessus lateralis - NSC Nucleus suprachiasmaticus - NVM Nucleus ventromedialis - RON right optic nerve - sac stratum album centrale - sfgs stratum fibrosum et griseum superficiale - sfpv stratum fibrosum periventriculare - sgc stratum griseum centrale - sgpv stratum griseum periventriculare - sm stratum marginale - soe stratum opticum pars externa - soi stratum opticum pars interna - SV saccus vascularis - Tel telencephalon - TL Torus longitudinalis - TM Tegmentum mesencephali - TO Tectum opticum - TROA Tractus opticus accessorius - TROdm Tractus opticus dorsomedialis - TROdmd Tractus opticus dorsomedialis dorsalis - TROdme Tractus opticus dorsomedialis pars externa - TROdmi Tractus opticus dorsomedialis pars interna - TROdmv Tractus opticus dorsomedialis ventralis - TROdmvd Tractus opticus dorsomedialis ventralis pars dorsalis - TROdmvv Tractus opticus dorsomedialis ventralis pars ventralis - TROM Tractus opticus marginalis - TROvl Tractus opticus ventrolateralis - TROvld Tractus opticus ventrolateralis dorsalis - TROvle Tractus opticus ventrolateralis pars externa - TROvli Tractus opticus ventrolateralis pars interna - TROvldd Tractus opticus ventrolateralis dorsalis pars dorsalis - TROvldv Tractus opticus ventrolateralis dorsalis pars ventralis - TROvlv Tractus opticus ventrolateralis pars ventralis - TS Torus semicircularis - v ventricle - VC Valvula cerebelli - I Nervus olfactorius - II Nervus opticus - V Nervus trigeminus - VII Nervus facialis - VIII Nervus octavolateralis - IX Nervus glossopharyngeus - X Nervus vagus     

The vestibulothalamic projections in the cat studied by retrograde axonal transport of horseradish peroxidase

Summary Horseradish peroxidase (HRP) was injected or iontophoretically ejected in various thalamic nuclei in 63 adult cats. In 11 other animals HRP was deposited outside the thalamic territory. The number and distribution of labelled cells within the vestibular nuclear complex (VC) were mapped in each case. To a varying degree all subgroups of VC appear to contribute to the vestibulothalamic projections. Such fibres are distributed to several thalamic areas. From the present investigation it appears that generally speaking, there exist three distinct vestibulothalamic pathways with regard to origin as well as to site of termination of the fibres. One projection appears to originate mainly in caudal parts of the medial (M) and descending (D) vestibular nuclei and in cell group z. This pathway terminates chiefly in the contralateral medial part of the posterior nucleus of the thalamus (POm) including the magnocellular part of the medial geniculate body (Mgmc), the ventrobasal complex (VB) and the area of the ventral lateral nucleus (VL) bordering on VB. A second projection originates mainly in the superior vestibular nucleus (S) and in cell group y and terminates mainly in the contralateral nucleus centralis lateralis (CL) and the adjoining nucleus paracentralis (Pc). A third, more modest, pathway originates chiefly in the middle M and D, with a minor contribution from S and cell group y, and terminates in the contralateral ventral nucleus of the lateral geniculate body (GLV). There is some degree of overlap between the origin of these three vestibulothalamic pathways.Abbreviations B.c. brachium conjunctivum - CeM nucleus centralis medialis thalami - CL nucleus centralis lateralis thalami - CM nucleus centrum medianum - D nucleus vestibularis descendons - f cell group f - g cell group g - GLD corpus geniculatum laterale dorsalis - GLV corpus geniculatum laterale ventralis - i.e. nucleus intercalatus - L nucleus vestibularis lateralis - LD nucleus lateralis dorsalis thalami - LIM lamina medullaris interna - Lim nucleus limitans - LP nucleus lateralis posterior thalami - M nucleus vestibularis medialis - MD nucleus medialis dorsalis thalami - MGmc corpus geniculatum mediale, pars magnocellularis - MGp corpus geniculatum mediale, pars principalis - N.cu.e. nucleus cuneatus externus - N.f.c. nucleus fasciculi cuneati - N.mes. V nucleus mesencephalicus nervi trigemini - NR nucleus ruber - N.tr.s. nucleus tractus solitarius - N. VII nervus facialis - N. VIII nervus statoacusticus - PC pedunculus cerebri - Pc nucleus paracentralis thalami - Pf nucleus parafascicularis - p.h. nucleus prepositus hypoglossi - PO posterior thalamic group - PO1 lateral part of PO - POm medial part of PO - Prt nucleus pretectalis - Pul pulvinar - R nucleus reticularis thalami - S nucleus vestibularis superior - Sg nucleus suprageniculatus - SN substantia nigra - Sv nucleus supravestibularis - Tr.s. tractus solitarius - VA nucleus ventralis anterior thalami - VL nucleus ventralis lateralis thalami - VPL nucleus ventralis posterior lateralis - VPL1 lateral part of VPL - VPLm medial part of VPL - VPM nucleus ventralis posterior medialis - x cell group x - y cell group y - z cell group z - V nucleus motorius nerve trigemini - X nucleus dorsalis nerve vagi - XII nucleus nervi hypoglossi     

The termination of the spinothalamic tract in the cat an experimental study with silver impregnation methods

Summary The termination of the spinothalamic tract (STT) in the cat has been studied light microscopically in Fink-Heimer and Nauta impregnated sections. Following lesions of the STT at various rostrocaudal levels of the spinal cord the degenerating fibres in the thalamus and subthalamus were mapped, mainly in transverse sections. The cervicothalamic tract was not injured by the lesions.The spinothalamic fibres enter the diencephalon through the mesencephalic reticular formation and terminate in the following regions: the medial portion of the magnocellular part of the medial geniculate body (MGmc), the ventrolateral portion of the medial part of the posterior nuclear complex (PO_m), the caudolateral and medial parts of the zona incerta (ZI), the nucleus centralis medialis (CeM), the nucleus parafascicularis (Pf), the lateral part of the nucleus centralis lateralis (CL), the medial and rostrolateral parts of the nucleus ventralis lateralis (VL). To reach these regions the fibres pass through the nucleus centrum medianum (CM), the nucleus subparafascicularis (SPf) and the nucleus paracentralis (Pc). The fibres that terminate in the VL pass through Forel's field H₁ and the external medullated lamina (EML). Conclusive results were not obtained concerning a termination in the CM. The spinothalamic fibres do not pass through nor terminate in the nucleus ventralis posterolateralis (VPL) and the nucleus reticularis (R). The VPL, defined as that portion of the ventral thalamus that receives terminal fibres from the dorsal column nuclei, has been found to extend rostrally only as far as Horsley-Clarke level anterior 10.5. The results strongly support the view that all the spinothalamic fibres terminate ipsilateral to their course in the ventral quadrant of the spinal cord. No signs of a somatotopical organization of the termination of the STT were found.List of Abbreviations Cd nucleus caudatus - CeM nucleus centralis medialis - CG circumaqueductal gray substance - CL nucleus centralis lateralis thalami - CM nucleus centrum medianum thalami - CP commissura posterior - CTT cervicothalamic tract - EML external medullated lamina - H₁ Forel's field H₁ - HP tractus habenulopeduncularis - LCN nucleus cervicalis lateralis - LG corpus geniculatum laterale - LP nucleus lateralis posterior thalami - MD nucleus medialis dorsalis thalami - MG corpus geniculatum mediale - MGmc corpus geniculatum mediale, pars magnocellularis - MGp corpus geniculatum mediale, pars principalis - ML medial lemniscus - MRF mesencephalic reticular formation - OT optic tract - Pc nucleus paracentralis thalami - Pf nucleus parafascicularis thalami - PO posterior group of thalamic nuclei - PO₁ lateral part of PO - PO_m medial part of PO - R nucleus reticularis thalami - SG nucleus suprageniculatus - STT spinothalamic tract - VA nucleus ventralis anterior - VL nucleus ventralis lateralis thalami - VM nucleus ventralis medialis thalami - VPI nucleus ventralis posterior inferior - VPL nucleus ventralis posterior lateralis thalami (VPL₁ + VPL_m) - VPL₁ lateral part of VPL - VPL_m medial part of VPL - VPM nucleus ventralis posterior medialis thalami - VPMpc parvocellular part of VPM - ZI zona incerta