Neuropeptide-FMRFamide-like immunoreactivity in Drosophila: development and distribution

Neuropeptide-FMRFamide-like immunoreactivity was characterized in the fruit fly, Drosophila melanogaster. In the adult central nervous system, a stereotypic pattern of immunoreactive cell bodies and immunoreactive nerve processes and varicosities was observed, indicating a neurochemical role for FMRFamide-like substance(s) in Drosophila. Localization of immunoreactivity in the central nervous system of early larval stage revealed that the majority of the prominent FMRFamide-like immunoreactive neurons were already differentiated. The FMRFamide-like immunoreactive neurons remain immunoreactive throughout postembryonic stage and persist in the adult central nervous system. In the larva, in addition to the central nervous system, FMRFamide-like immunoreactivity was localized in the fibers innervating the ring gland, in the ganglion innervating the gut and in the gastric caeca.     

The distribution of bovine pancreatic polypeptide/FMRFamide-like immunoreactivity in the ventral nervous system of the locust

The distribution of bovine pancreatic polypeptide (BPP) FMRFamide-like immunoreactivity is described in the ganglia of the ventral nerve cord and in the peripheral median nervous system of the locust, Schistocerca gregaria. Immunoreactive cell bodies occur in three regions of the thoracic ganglia: 1) two pairs of cells lie in the anterior of the ganglion ventral to the root of nerve 1 and the anterior ventral association centre; 2) a group of cells lies in the ventral midline at the level at which nerves 3 and 4 leave the ganglion; 3) and two bilaterally symmetrical, posterior lateral groups lie between nerves 5 and 6 at the edge of the ganglion. Immunoreactive cell bodies in the suboesophageal and abdominal ganglia are confined to the midline and are distributed along the anterior-posterior axis both dorsally and ventrally. The processes of the posterior lateral groups have been traced into the neurohaemal organs of the median nerve and beyond. In the periphery such processes innervate the salivary glands and various muscles. The nature of the endogenous antigen contained in the immunoreactive cells has been investigated with the use of antisera against other peptides of the pancreatic polypeptide family, namely avian pancreatic polypeptide, neuropeptide Y, and peptide YY. In addition, BPP antisera not specific for the C terminal hexapeptide have been tested. Liquid preabsorption experiments with BPP and FMRFamide (the molluscan cardioacceleratory peptide) suggest that the endogenous peptide antigen contained in the stained neurones may belong to the pancreatic polypeptide family or to the FMRFamide family.     

FMRFamide-related peptides,partial serotonin depletion,and osmoregulation in Helisoma duryi (mollusca: pulmonata)

Serotonergic neurons were studied by specific histological methods, and neurons containing Phe-Met-Arg-Phe-NH₂ (FMRFamide)-related heptapeptides were identified with an antiserum specific for these substances in the central nervous system of the freshwater snail Helisoma duryi. Serotonergic neurons and their axons are present in all of the ganglia (paired buccal, cerebral, pedal, pleural, parietal, and single visceral) and major nerves of the central nervous system. Large neurons containing FMRFamide-related peptide immunoreactivity are located in the left parietal and visceral ganglia, whereas a few small neurons are located in the cerebral and pedal ganglia. Both serotonergic and FMRFamide-related peptide-immunoreactive dendrites and varicosities were observed in the kidney. A second antiserum with high affinity for FMRFamide-related heptapeptides was used to measure the levels of the immunoreactive material in various tissues, and such material was found in every tissue analyzed. When snails were exposed to a medium isosmotic to their hemolymph, the levels of immunoreactive FMRFamide-related peptides increased in the hemolymph, central nervous system, mantle, and kidney. Injection of dihydroxytryptamine, which is known to deplete serotonin content in the snail, also reduced the levels of FMRFamide-related-immunoreactive material in the above tissues. Therefore, serotonin may influence the levels of FMRFamide-related peptides in tissues by regulating the rate of their synthesis, axonal transport, or release. Both serotonin and FMRFamide-related peptides could be involved in osmoregulation. J. Comp. Neurol. 393:25–33, 1998. © 1998 Wiley-Liss, Inc.     

Distribution of galanin-like immunoreactive elements in the brain of the adult lamprey Lampetra fluviatilis

Galanin is a brain-gut peptide present in the central nervous system of vertebrates and invertebrates. The distribution of galanin-like immunoreactive perikarya and fibers in the brain of the river lamprey Lampetra fluviatilis (Agnatha) has been studied immunocytochemically by using antisera against rat and porcine galanin. Galanin-like immunoreactive perikarya were seen in the telencephalon and mediobasal diencephalon. In the telencephalon, they were present in the nucleus olfactorius anterior, nucleus basalis, and especially, in the nucleus commissurae anterioris. The diencephalon contained most of the immunoreactive neurons. They were located in the nucleus commissurae praeinfundibularis, nucleus ventralis hypothalami, nucleus commissurae postinfundibularis, nucleus ventralis thalami, and nucleus dorsalis thalami pars medius. Most of the galanin-like immunoreactive infundibular neurons showed apical processes contacting the cerebrospinal fluid. Immunoreactive fibers and terminals were widely distributed throughout the neuraxis. In the telencephalon, the richest galaninergic innervation was found in the nucleus olfactorius anterior, lobus subhippocampalis, corpus striatum, and around the nucleus septi and the nucleus praeopticus. In the diencephalon, the highest density of galanin-like immunoreactive fibers was seen in the nucleus commissurae postopticae, nucleus commissurae praeinfundibularis, nucleus ventralis hypothalami, nucleus dorsalis hypothalami, and neurohypophysis. In the mesencephalon and rhombencephalon, the distribution of immunoreactive fibers was heterogeneous, being most pronounced in a region between the nucleus nervi oculomotorii and the nucleus interpeduncularis mesencephali, in the nucleus isthmi, and in the raphe region. A subependymal plexus of immunoreactive fibers was found throughout the ventricular system. The distribution of immunoreactive neurons and fibers was similar to that of teleosts but different to those of other vertebrate groups. The possible hypophysiotropic and neuroregulatory roles of galanin are discussed. © 1996 Wiley-Liss, Inc.     

Localization of myomodulin-like immunoreactivity in the central nervous system and peripheral tissues of Aplysia californica.

The distribution of myomodulin-like peptides in the nervous system of Aplysia californica was examined by using immunocytochemical techniques. Neurons and cell clusters containing immunoreactive material were located in each of the major central ganglia. Myomodulin-like immunoreactivity was also present in fibers in each of the connectives between the ganglia and in peripheral nerves. Varicosities containing immunoreactive material were located on specific regions of peripheral tissues associated with the feeding, digestive, cardiovascular, and reproductive systems. Double-labeling experiments were used to demonstrate myomodulin-like immunoreactivity in two identified neurons, the motor neuron B16 in the buccal ganglion and the widely acting interneuron L10 in the abdominal ganglion. Structures in the eye and cerebral ganglion that may correspond to the optic circadian pacemaker system were also stained. The central and peripheral distribution of myomodulin-like immunoreactivity indicates that this family of neuropeptides is present in specific efferent, afferent, and interneuronal elements that participate in a diversity of neural circuits in Aplysia.     

Distribution of buccalin-like immunoreactivity in the central nervous system and peripheral tissues of Aplysia californica.

The neuropeptide buccalin A was originally purified and sequenced from a nerve-muscle system used in feeding-related behaviors of Aplysia californica in which it has been proposed that it acts as a modulatory cotransmitter. The distribution of buccalin-like immunoreactivity in the central ganglia and in peripheral tissues of Aplysia californica was examined by whole mount immunohistochemical techniques. Immunoreactive material was located in specific cell bodies and clusters of neurons in each of the ganglia. Immunoreactive fibers were present in each of the connectives between ganglia, in tracts coursing through the ganglia, and in the majority of the peripheral nerves. Most fibers were smooth in contour, but some had regularly spaced swellings. Varicosities containing immunoreactive material were located on specific neuronal somata and on certain tissues associated with the feeding, circulatory, digestive, and reproductive systems. The specific and widespread distribution of buccalin-like immunoreactivity supports the hypothesis that members of the buccalin peptide family act as neuromodulators or neurotransmitters in a variety of central and peripheral circuits in Aplysia.     

Ontogenesis of neurons producing luteinizing hormone-releasing hormone (LHRH) in the nervus terminalis of the rat

Immunoreactive luteinizing hormone-releasing hormone (LHRH) was first detected at 15 days of gestation in ganglion cells associated with the peripheral, intracranial, and central parts of the nervus terminalis of the rat. LHRH was not detected in any other structure of the central nervous system at this age. In the 17-day-old fetal rat, 62% of the total LHRH-reactive neuronal population was found in ganglion cells of the nervus terminalis. At this same age, immunoreactive beta-luteinizing hormone (beta-LH) was first seen in gonadotropes of the anterior pituitary gland. At 19 days of gestation, 31% of the total number of LHRH-reactive neurons observed in the rat brain was found in the nervus terminalis, and immunoreactive processes were first seen in the organum vasculosum of the lamina terminalis and in the median eminence. Our data indicate that from 15 to 19 days of gestation the nervus terminalis is a principal source of LHRH in the fetal rat. Presence of the decapeptide in the nervus terminalis prior to appearance of beta-LH in the anterior pituitary suggests a possible role for LHRH in this system on maturation of the gonadotropes and differentiation of the brain-pituitary-gonadal axis.     

Neuropeptides myomodulin,small cardioactive peptide,and buccalin in the central nervous system of Lymnaea stagnalis: Purification,immunoreactivity, and artifacts

The neuropeptides myomodulin, small cardioactive peptide (SCP), and buccalin are widely distributed in the phylum Mollusca and have important physiological functions. Here, we describe the detailed distribution of each class of peptide in the central nervous system (CNS) of the snail Lymnaea stagnalis by the use of immunocytochemical techniques combined with dye-marking of electrophysiologically identified neurons. We report the isolation and structural characterization of a Lymnaea myomodulin, PMSMLRLamide, identical to myomodulin A of Aplysia californica. Myomodulin immunoreactivity was localized in all 11 ganglia, in their connectives, and in peripheral nerves. In many cases, myomodulin immunoreactivity appeared localized in neuronal clusters expressing FMRFamide-like peptides, but also in a large number of additional neurons. Double-labelling experiments demonstrated myomodulin immunoreactivity in the visceral white interneuron, involved in regulation of cardiorespiration. SCP-like immunoreactivity also appeared in all ganglia, and double-labelling experiments revealed that in many locations it was specifically associated with clusters expressing distinct exons of the FMRFamide gene that are differentially expressed in the CNS. Characterization of the two types of SCP-antisera used in this study, however, suggested that they cross-reacted with both FMRFamide and N-terminally extended FMRFamide-like peptides. Selective preadsorption with these cross-reacting peptides resulted in elimination of the widespread staining and retention of bona fide SCP immunoreactivity in the buccal and pedal ganglia only. Buccalin immunoreactivity was limited to the buccal and pedal ganglia. It did not coincide with the distribution of either myomodulin or SCP. Most immunoreactive clusters were found in the pedal ganglia. © 1994 Wiley-Liss, Inc.     

FMRFamide: An endogenous peptide with marked inhibitory effects on opioid-induced feeding behavior

The peptide FMRFamide (Phe-Met-Arg-Phe-NH2), which displays a broad phylogenetic distribution, is considered to have important regulatory influences on basic functions in invertebrates. Extensive FMRFamide-like immunoreactive neuropeptides have also been demonstrated in the mammalian central nervous system, suggesting a possible physiological role for these peptides in mammals. There is evidence that FMRFamide, and/or related neuropeptides, may modulate opioid-mediated responses. Intracerebroventricular (ICV) administrations of FMRFamide inhibit in a dose-dependent manner (0.01-10 micrograms) mu- (morphine) and kappa- (U-50,488H) opiate-induced feeding in the laboratory mouse. In deer mice, FMRFamide inhibits the display of exogenous opiate-induced components of natural feeding behavior, such as food hoarding and food ingestion. In addition, ICV administrations of FMRFamide also antagonize endogenous opioid-mediated, stress-induced feeding in mice. These observations suggest that FMRFamide, or FMRFamide-like peptides present in the mammalian brain, may have important roles in the control of opioid-mediated feeding.     

Ontogeny of the F8Famide-like (morphine-modulating) peptides in the central nervous system of rats.

FLFQPQRF-NH2 (F8Famide; FMRFamide-like peptide; morphine-modulating peptide) is a peptide isolated from bovine brain. It has some opiate analgesia modulating effects. In an adult rat central nervous system, F8Famide-like immunoreactivity is found in high concentrations in the posterior pituitary, hypothalamus, pons, medulla, and dorsal spinal cord. By using immunohistochemistry and radioimmunoassay, we studied the development of the F8Famide-immunoreactive system in the rat central nervous system during the ontogeny. F8Famide-immoreactive fibers and terminals first appeared in the median eminence on the twentieth embryonal day. Postnatally the F8Famide-immunoreactive system developed rapidly both in the brain and spinal cord, the immunoreactive structures having an adultlike distribution by the age of 1 week. A transient increase of the F8Famide-immunoreactive material was observed during the third and fourth postnatal weeks. By the age of 4 weeks, the F8Famide-containing neuronal system was adultlike both in distribution and quantity. The results suggest that the F8Famide-like peptides may act as neurotransmitters or neuromodulators from the time of their appearance in the brain and spinal cord. The early appearance and the distribution of the F8Famide-like immunoreactivity suggest that these peptides may participate, in addition to nociceptive mechanisms, in the regulation of blood pressure, feeding behaviour, and endocrine functions.     

Locustatachykinin immunoreactivity in the blowfly central nervous system and intestine

An antiserum raised against locustatachykinin I, one of four myotropic peptides that have been isolated from the locust brain and corpora cardiaca, was characterized by enzyme-linked immunosorbent assay (ELISA) and used for immunocytochemical detection of neurons and endocrine cells in the nervous system and intestine of the blowfly Calliphora vomitoria. The ELISA characterization indicated that the antiserum recognizes the common C-terminus sequence of the locustatachykinins I-III. Hence, the cross reaction with locustatachykinin IV is less, and in competitive ELISAs no cross reaction was detected with a series of vertebrate tachykinins tested. It was also shown that the antiserum recognized material in extracts of blowfly heads, as measured in ELISA. In high-performance liquid chromatography the extracted locustatachykinin-like immunoreactive (Lom TK-LI) material eluted in two different ranges. A fairly large number of LomTK-LI neurons was detected in the blowfly brain and thoracicoabdominal ganglion. A total of about 160 LomTK-LI neurons was seen in the proto-, deuto-, and tritocerebrum and subesophageal ganglion. Immunoreactive processes from these neurons could be traced in many neuropil regions of the brain: superior and dorsomedian protocerebrum, optic tubercle, fan-shaped body and ventral bodies of the central complex, all the glomeruli of the antennal lobes, and tritocerebral and subesophageal neuropil. No immunoreactivity was seen in the mushroom bodies or the optic lobes. In the fused thoracicoabdominal ganglion, 46 LomTK-LI neurons could be resolved. The less evolved larval nervous system was also investigated to obtain additional information on the morphology and projections of immunoreactive neurons. In neither the larval nor the adult nervous systems could we identify any efferent or afferent immunoreactive axons or neurosecretory cells. The widespread distribution of LomTK-LI material in interneurons suggests an important role of the native peptide(s) as a neurotransmitter or neuromodulator within the central nervous system. Additionally a regulatory function in the intestine is indicated by the presence of immunoreactivity in endocrine cells of the midgut.     

Immunoreactive myelin basic protein in cerebrospinal fluid of patients with peripheral neuropathies

The presence of myelin basic protein (MBP)-like material in cerebrospinal fluid (CSF) usually reflects breakdown of central nervous system myelin. Immunoreactive MBP levels were measured in 70 CSF specimens from 66 patients with a variety of peripheral neuropathies. Immunoreactive MBP was present in CSF in 70% (16 of 23) of patients with biopsy-proved chronic demyelinating polyneuropathies, whereas in neuropathies producing primarily axonal damage it was present in only 22% (5 of 23). In Guillain-Barré syndrome, 45% (9 of 20) of patients had immunoreactive MBP in the CSF. We conclude that MBP-like material is present in the CSF of most patients with longstanding demyelinating polyradiculoneuropathies and probably reflects detection of peripheral nervous system P1 protein.     

Localization of serotonin in the nervous system of Biomphalaria glabrata, an intermediate host for schistosomiasis

The digenetic trematode Schistosoma mansoni that causes the form of schistosomiasis found in the Western Hemisphere requires the freshwater snail Biomphalaria glabrata as its primary intermediate host. It has been proposed that the transition from the free-living S. mansoni miracidium to parasitic mother sporocyst depends on uptake of biogenic amines, e.g. serotonin, from the snail host. However, little is known about potential sources of serotonin in B. glabrata tissues. This investigation examined the localization of serotonin-like immunoreactivity (5HTli) in the central nervous system (CNS) and peripheral tissues of B. glabrata. Emphasis was placed on the cephalic and anterior pedal regions that are commonly the sites of S. mansoni miracidium penetration. The anterior foot and body wall were densely innervated by 5HTli fibers but no peripheral immunoreactive neuronal somata were detected. Within the CNS, clusters of 5HTli neurons were observed in the cerebral, pedal, left parietal, and visceral ganglia, suggesting that the peripheral serotonergic fibers originate from the CNS. Double-labeling experiments (biocytin backfill × serotonin immunoreactivity) of the tentacular nerve and the three major pedal nerves (Pd n. 10, Pd n. 11, and Pd n. 12) disclosed central neurons that project to the cephalopedal periphery. Overall, the central distribution of 5HTli neurons suggests that, as in other gastropods, serotonin regulates the locomotion, reproductive, and feeding systems of Biomphalaria. The projections to the foot and body wall indicate that serotonin may also participate in defensive, nociceptive, or inflammation responses. These observations identify potential sources of host-derived serotonin in this parasite-host system. Inc.     

Somatostatinlike immunoreactive neurons in the hedgehog (Erinaceus europaeus) and the sheep (Ovis aries) central nervous system

The morphology and distribution of somatostatinlike immunoreactive perikarya in the central nervous system of the hedgehog and sheep have been studied by means of the peroxidase-antiperoxidase immunohistochemical method. Intracerebroventricular colchicine infusion not only enhanced the immunostaining but also revealed new immunoreactive cell bodies. In both hedgehog and sheep immunoreactive neurons of various forms, ranging from 12 to 28 microns in diameter, were observed in a number of homologous brain structures. However, some species-related differences were noticed. Thus, somatostatinlike immunoreactive neurons were found only in the hedgehog anterior olfactory nucleus, olfactory tubercle, nucleus accumbens, medial parabrachial nucleus, raphe nuclei of the medulla, and spinal trigeminal nucleus, whereas some somatostatin-positive neurons were observed in the locus coeruleus and the pontine reticular formation of the sheep only. Mapping of peptides in species like sheep and hedgehog, with basically different orientations of living behaviour, may contribute in strengthening or extending our views concerning the role of peptides in the central nervous system of mammals.     

Distribution of myomodulin-like and buccalin-like immunoreactivities in the central nervous system and peripheral tissues of the mollusc,Clione limacina

The distribution of the myomodulin-like and buccalin-like immunoreactivities in the central nervous system and peripheral tissues associated with feeding was examined in the pteropod mollusc Clione limacina by using wholemount immunohistochemical techniques. Immunoreactive neurons and cell clusters were located in all central ganglia except the pleural ganglia, with approximately 50 central neurons reactive to myomodulin antiserum and 60 central neurons reactive to buccalin antiserum. All central ganglia contained a dense network of myomodulin- and buccalin-immunoreactive processes in their neuropil regions and connectives. In the periphery, the primary attention was focused on the tissues associated with feeding, especially feeding structures unique to Clione, such as hook sacs and buccal cones, which are used for prey capture and acquisition. All of these feeding structures contained myomodulin-immunoreactive and buccalin-immunoreactive fibers, with each peptide family showing specific innervation fields that were common in buccal cones and were totally different in the hook sacs. The specific central and peripheral distribution of myomodulin-like and buccalin-like immunoreactivities as well as specific effects of the exogenous peptides on identified neurons involved in the control of feeding behavior and swimming suggest that neuropeptides from myomodulin and buccalin families act as neurotransmitters or neuromodulators in a variety of central circuits and in the peripheral neuromuscular systems associated with feeding in Clione limacina. J. Comp. Neurol. 381:41-52, 1997. © 1997 Wiley-Liss, Inc.     

Immunocytochemical localization of pedal peptide in the central nervous system of the gastropod mollusc Tritonia diomedea

Tritonia pedal ganglion peptides (TPeps) are a trio of pentadecapeptides isolated from the brain of the nudibranch Tritonia diomedea. TPeps have been shown both to increase the beating rate of ciliated cells of Tritonia and to accelerate heart contractions in the mollusc Clione limacina. Here we examine the immunocytochemical distribution of TPeps in the Tritonia central nervous system. We found the brain and buccal ganglia to be rich sources of TPep immunoreactivity. Specific cells in both structures, some of them previously identified, were immunoreactive. Moreover, immunoreactive fibers were seen connecting ganglia and exiting almost all the major nerves. In the brain, we found that the paired, ciliated statocysts apparently receive TPep innervation. In addition, we observed unstained cell bodies in each buccal ganglion with extensive TPep immunoreactive projections surrounding their somata and primary neurites. Similar projections were not observed in the brain. We also compared the TPep immunoreactivity with that of SCP(b) in the buccal ganglia. We observed many neurons and processes that were immunoreactive to both peptides. One neuron that contains both TPep- and SCP(b)-like peptides (B12) has an identified role in the Tritonia feeding network. Together, these findings suggest that TPeps may play an active role in the central nervous system of Tritonia as neurotransmitters modulating orientation, swimming, and feeding.     

Distribution and partial characterization of FMRFamide-like peptides in the stomatogastric nervous systems of the rock crab, Cancer borealis, and the spiny lobster, Panulirus interruptus

The distribution of FMRFamide-like peptides was studied in the complete stomatogastric nervous system [the paired commissural ganglia, single oesophageal ganglion, and the single stomatogastric ganglion (STG)] of two decapod crustacean species, the spiny lobster Panulirus interruptus and the rock crab Cancer borealis, by using immunocytochemical techniques. Antiserum 231 from the O'Donohue laboratory and antiserum 671C (described here) gave essentially the same staining patterns. In the commissural ganglia of both species there were ten to 20 stained neurons and dense neuropilar staining. The oesophageal ganglion of the crab had four stained neurons. Lucifer Yellow backfills followed by immunostaining showed that the two larger stained neurons of the oesophageal ganglion sent processes into the inferior ventricular nerve. The two smaller neurons sent processes into the inferior oesophageal nerves. The oesophageal ganglion of the lobster had two stained neurons that sent processes into the inferior ventricular nerve as well. None of the somata of the STG stained in either species, but in both species stained fibers were seen in the stomatogastric nerve that entered the STGs and ramified profusely throughout the neuropil. In some preparations of the crab, a stained fiber was visible in the dorsal ventricular nerve. The amounts of the FMRFamide-like peptides found in all regions of the nervous system of P. interruptus and C. borealis were determined by radioimmune assay (RIA). Column chromatography and high-performance liquid chromatography suggest that, in both species, much if not all of the RIA-assayable material is accountable for by peptides that are larger and more hydrophobic than FMRFamide.     

Distribution of adrenomedullin-like immunoreactivity in the rat central nervous system by light and electron microscopy

Adrenomedullin is a peptide of marked vasodilator activity first isolated from human pheochromocytoma and subsequently demonstrated in other mammalian tissues. Using a polyclonal antiserum against human adrenomedullin-(22-52) amide and the avidin-biotin peroxidase complex technique, we have demonstrated by light and electron microscopy that adrenomedullin-like immunoreactivity is widely distributed in the rat central nervous system. Western blotting of extracts of different brain regions demonstrated the fully processed peptide as the major form in the cerebellum, whereas a 14-kDa molecular species and a small amount of the 18-kDa propeptide were present in other brain regions. Immunoreactive neurons and processes were found in multipolar neurons and pyramidal cells of layers IV-VI of the cerebral cortex and their apical processes, as well as in a large number of telencephalic, diencephalic, mesencephalic, pontine and medullary nuclei. Cerebellar Purkinje cells and mossy terminal nerve fibers as well as neurons of the cerebellar nuclei were immunostained, as were neurons in area 9 of the anterior horn of the spinal cord. Immunoreactivity was also found in some vascular endothelial cells and surrounding processes that probably originated from perivascular glial cells. Electron microscopy confirmed the light microscopy findings and showed the reaction product in relation to neurofilaments and the external membrane of small mitochondria. Immunoreactive terminal boutons were occasionally seen. The distribution of adrenomedullin-like immunoreactivity in the central nervous system suggests that it has a significant role in neuronal function as well as in the regulation of regional blood flow.     

Distribution of luteinizing hormone-releasing hormone in the nervus terminalis and brain of the mouse detected by immunocytochemistry

Immunoreactive luteinizing hormone-releasing hormone (LHRH) was localized in a relatively large number of ganglion cells and fibers of the nervus terminalis of neonatal and adult mice, indicating that this nerve is a substantial source of LHRH in the mouse brain. Whole-head specimens of neonatal mice, prior to calcification of the cranium, revealed an extensive distribution of LHRH neurons and fine fibers throughout the peripheral, intracranial, and central parts of the nervus terminalis. The most striking difference between the neonatal and adult animals, in the nervus terminalis, was the increase in immunoreactive axons that made up the fiber bundles of this nerve. In the adult mouse, the intracranial and central projections were composed of thick fascicles of immunoreactive axons, ensheathed by glial cells and accompanied by ganglia that contained both LHRH-reactive and nonimmunoreactive neurons. LHRH-immunoreactive cells and axons were seen in a branch of the nervus terminalis that coursed along the medial, posterodorsal aspect of the olfactory bulb and in branches of this nerve that accompany the vomeronasal nerves to the accessory olfactory bulb. A few LHRH neurons and many immunoreactive processes were seen in the accessory and main olfactory bulbs. LHRH-reactive neurons were seen in the hypothalamus and extrahypothalamic structures. Examination of adult mouse brains revealed a pattern of distribution and number of immunoreactive neurons similar to that seen in the neonate. However, many more LHRH-reactive axons were seen in all areas of the brain of the mature animal.     

Neuropeptide proctolin (H-Arg-Try-Leu-Pro-Thr-OH): immunocytochemical mapping of neurons in the central nervous system of the cockroach

Proctolinlike immunoreactivity was mapped in the central nervous system of the cockroach, Periplaneta americana, by using whole-ganglion immunoreacted preparations. The procedure for this immunohistochemical staining of whole-mounts is described. Immunoreactivity was confined to neuronal cell bodies and and processes. These were found in all ganglia of the CNS. The cells varied in the consistency and intensity of their staining. The occurrence and variability of staining is described in detail. Cell bodies were found in the dorsal, ventral, and lateral regions of the ganglia. The highest number of cell bodies was found in the terminal ganglion and the lowest number in the cerebral ganglion. Those in the cerebral ganglion occurred mainly in the tritocerebral lobes. The distribution of immunoreactive cell bodies correlated with results previously obtained by radioimmunoassay. Immunoreactive processes were detected in all interganglionic connectives and many ganglionic nerve roots. Dense ramifications of immunoreactive processes and variocosities were detected in many of the ganglia. The widespread presence of immunoreactivity suggests that proctolin has diverse central and peripheral functions. The mapping immunoreactive neuronal somata provides a valuable step in the identification of putative proctolin-containing neurons suitable for further biochemical, anatomical, and physiological analysis.