Dendritic localization of type II calcium calmodulin-dependent protein kinase mRNA in normal and reinnervated rat hippocampus.

In situ hybridization histochemistry has revealed a diffuse distribution of the alpha subunit of type II calcium calmodulin-dependent protein kinase (CaM II kinase alpha) mRNA in the neuropil of regions containing CaM II kinase alpha-expressing cells and has led some to propose that it may be expressed in dendrites. In order to determine if CaM II kinase alpha mRNA is expressed in dendrites and if the gene encoding CaM II kinase alpha is regulated in response to synaptic reinnervation, we examined its expression in the hippocampus of normal rats, of rats that had received a unilateral injection of kainic acid and of rats with a unilateral entorhinal cortex lesion. The relatively specific elimination of the CA3 pyramidal cells by kainate lesions precisely correlated with the loss of CaM II kinase alpha cRNA hybridization in the stratum radiatum as well as the stratum pyramidale. Following entorhinal cortex lesions, during the period of new synapse formation in the dentate gyrus, there was no detectable change in the level of CaM II kinase alpha gene expression. These data suggest that CaM II kinase alpha mRNA is expressed in the dendrites of hippocampal pyramidal cells and, therefore, is likely to be expressed in dendrites in other regions of the central nervous system exhibiting CaM II kinase alpha cRNA labeling in the neuropil. However, changes in expression were not found to accompany new synapse formation.     

Visualization of stress-responsive inhibitory circuits in the GAD65-eGFP transgenic mice

Here, we have revealed that a subset of GABAergic neurons in the mouse brain became activated during systemic stress response. Stress-induced expression of immediate early gene product c-Fos, as a marker of neuronal activation was visualized in a transgenic mouse line expressing enhanced green fluorescent protein (eGFP) under the control of the regulatory region of mouse glutamic acid decarboxylase (GAD) 65 gene. In most GABAergic regions egfp transgene expression corresponded to acknowledged distribution of GABA neurons. Ether inhalation, as a strong systemic stressor induced c-Fos expression throughout the stress-related circuit, and did not affect the distribution and expression of the eGFP-transgene. Stress provoked strong neuronal activation in the piriform cortex, midline thalamic nuclei, lateral septum (LS), bed nucleus of the stria terminalis (BNST), and in parvocellular part of the hypothalamic paraventricular nucleus (PVN) as revealed by c-Fos immunfluorescence. Cells in the LS, BNST, and AHA including the subparaventricular zone (SPVZ) displayed significant eGFP/c-Fos co-localization, revealing stress-responsive GABAergic neurons. None of the stress-activated neurons within the medial parvocellular subdivision of the PVN were GABAergic. Our present results suggest that stress-recruited GABAergic neuron populations are preferentially located in distinct limbic and hypothalamic regions and these neurons might be involved in an inhibitory mechanism that counteract the endocrine, autonomic and behavioral aspects of the stress response. Furthermore, the present GAD65-eGFP transgenic model seems to be a relevant tool to analyze inhibitory control of the central stress circuit at single cell level.     

Ca2+/calmodulin-dependent protein kinase II in the rat cerebellum: an immunohistochemical study with monoclonal antibodies specific to either alpha or beta subunit.

Monoclonal antibodies specific to either alpha or beta subunit of Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) of the rat brain were produced and the distribution of each subunit in the rat cerebellum was examined immunohistochemically. Each antibody detected solely the corresponding subunit in immunoblot analysis of crude homogenates of the rat forebrain and cerebellum, and purified CaM kinase II from the rat forebrain. Immunoreactivity for alpha subunit was present selectively in Purkinje cells: perikarya, dendrites with their spines, axons and their terminal-like structures in the cerebellar cortex, cerebellar nuclei and lateral vestibular nucleus. Many of these alpha subunit-immunoreactive axons from the cerebellum were traced only through the inferior cerebellar peduncle. beta Subunit was detected in perikarya and dendrites of a limited number of Purkinje cells, many granule cells and neurons in the cerebellar nuclei. Thus, different distributions of alpha and beta subunits of CaM kinase II in the cerebellum were demonstrated.     

Localization of the cGMP-dependent protein kinases in relation to nitric oxide synthase in the brain

The distributions of the type I and type II isoforms of cGMP-dependent protein kinase were determined in the rat brain using immunohistochemistry and in situ hybridization, and compared with the localization of NO synthase determined with NADPH-diaphorase histochemistry. The type I cGMP-dependent protein kinase was highly expressed in the Purkinje cells of the cerebellar cortex, where it was closely associated with the NO synthase containing granule and basket cells. This kinase was also found in neurons in the dorsomedial nucleus of the hypothalamus, where it may be regulated by NO or atriopeptides. The type I kinase was not detected in other central neurons. In contrast, the type II kinase was widely distributed in the brain. In particular, it was highly expressed in the olfactory bulb, cortex, septum, thalamus, tectum and various brainstem nuclei. Many regions expressing this kinase also contained, or received innervation from NO synthase positive neurons. These results indicate that type I cGMP-dependent protein kinase may act as a downstream effector for NO only in the cerebellar cortex and the dorsomedial hypothalamus. The type II cGMP-dependent protein kinase appears to be a major mediator of NO actions in the brain.     

The turtle thalamic anterior entopeduncular nucleus shares connectional and neurochemical characteristics with the mammalian thalamic reticular nucleus

Neurochemical and key connectional characteristics of the anterior entopeduncular nucleus (Enta) of the turtle (Testudo horsfieldi) were studied by axonal tracing techniques and immunohistochemistry of parvalbumin, gamma-aminobutyric acid (GABA) and glutamic acid decarboxylase (GAD). We showed that the Enta, which is located within the dorsal peduncle of the lateral forebrain bundle (Pedd), has roughly topographically organized reciprocal connections with the dorsal thalamic visual nuclei, the nucleus rotundus (Rot) and dorsal lateral geniculate nucleus (GLd). The Enta receives projections from visual telencephalic areas, the anterior dorsal ventricular ridge and dorsolateral cortex/pallial thickening. Most Enta neurons contained GABA and parvalbumin, and some of them were retrogradely labeled when the tracer was injected into the visual dorsal thalamic nuclei. Further experiments using double immunofluorescence revealed colocalization of GAD and parvalbumin in the vast majority of Enta neurons, and many of these cells showed retrograde labeling with Fluoro-gold injected into the Rot and/or GLd. According to these data, the Enta may be considered as a structural substrate for recurrent inhibition of the visual thalamic nuclei. Based on morphological and neurochemical similarity of the turtle Enta, caiman Pedd nucleus, the superior reticular nucleus in birds, and the thalamic reticular nucleus in mammals, we suggest that these structures represent a characteristic component which is common to the thalamic organization in amniotes.     

Neurotransmitter and neuromodulator systems of the rat inferior colliculus and auditory brainstem studied by in situ hybridization

This study was concerned with the distribution of a variety of putative neuromodulator and neurotransmitter systems in auditory regions of the rat brainstem using in situ hybridization histochemistry. Serial brain sections were screened for the presence of mRNAs for (i) precursors of the neuroactive substances cholecystokinin, somatostatin, proenkephalin and substance P (preprotachykinin), (ii) glutamic acid decarboxylase, the key synthesizing enzyme for GABA, or (iii) subunits l, 2 and 3 of the GABA_A receptor. Detectable message for all of these probes was found in at least one auditory brainstem area. There were clear differences in the distribution of the various mRNAs in subregions of the inferior colliculus, superior olivary complex, lateral lemniscus and cochlear nucleus. Cells expressing mRNA for glutamic acid decarboxylase were most prominent in the inferior colliculus, but were also present in all lower auditory brainstem nuclei, except the medial superior olivary nucleus and medial nucleus of trapezoid body. The mRNA for GABA_A1 receptor subunits was detectable in all auditory regions investigated, although at different levels of expression. GABA_A2 and 3 mRNA signals were seen in inferior colliculus, lateral lemniscus and in almost all superior olivary complex regions, but in fewer cells and at lower levels than the GABA_A1 subtype. Moderate to high levels of preprocholecystokinin mRNA expression were seen in all subregions of the inferior colliculus. In other auditory brainstem areas, preprocholecystokinin mRNA levels were either low or absent. With regard to mRNAs for the neuroactive peptides somatostatin, preprotachykinin and preproenkephalin, all were expressed in the inferior colliculus but there were differences in their cellular distribution. For example, there were almost no preprotachykinin mRNA expressing cells in the central nucleus of inferior colliculus and levels of somatostatin mRNA were especially high in the dorsal cortex and in layer 3 of the external cortex of inferior colliculus. There were also differences in the pattern of expression of these mRNAs in the various brainstem auditory nuclei; there was no preprotachykinin mRNA in any part of the superior olivary complex, only somatostatin mRNA was found in the ventral cochlear nucleus, and expression of preproenkephalin mRNA was pronounced in the ventral nucleus of the trapezoid body and the rostral periolivary zone. The data are considered in light of the connectivity and functional organization of the auditory brainstem.     

Stereological estimates of dopaminergic, GABAergic and glutamatergic neurons in the ventral tegmental area, substantia nigra and retrorubral field in the rat

Midbrain dopamine neurons in the ventral tegmental area, substantia nigra and retrorubral field play key roles in reward processing, learning and memory, and movement. Within these midbrain regions and admixed with the dopamine neurons, are also substantial populations of GABAergic neurons that regulate dopamine neuron activity and have projection targets similar to those of dopamine neurons. Additionally, there is a small group of putative glutamatergic neurons within the ventral tegmental area whose function remains unclear. Although dopamine neurons have been intensively studied and quantified, there is little quantitative information regarding the GABAergic and glutamatergic neurons. We therefore used unbiased stereological methods to estimate the number of dopaminergic, GABAergic and glutamatergic cells in these regions in the rat. Neurons were identified using a combination of immunohistochemistry (tyrosine hydroxylase) and in situ hybridization (glutamic acid decarboxylase mRNA and vesicular glutamate transporter 2 mRNA). In substantia nigra pars compacta 29% of cells were glutamic acid decarboxylase mRNA-positive, 58% in the retrorubral field and 35% in the ventral tegmental area. There were further differences in the relative sizes of the GABAergic populations in subnuclei of the ventral tegmental area. Thus, glutamic acid decarboxylase mRNA-positive neurons represented 12% of cells in the interfascicular nucleus, 30% in the parabrachial nucleus, and 45% in the parainterfascicular nucleus. Vesicular glutamate transporter 2 mRNA-positive neurons were present in the ventral tegmental area, but not substantia nigra or retrorubral field. They were mainly confined to the rostro-medial region of the ventral tegmental area, and represented approximately 2-3% of the total neurons counted ( approximately 1600 cells). These results demonstrate that GABAergic and glutamatergic neurons represent large proportions of the neurons in what are traditionally considered as dopamine nuclei and that there are considerable heterogeneities in the proportions of cell types in the different dopaminergic midbrain regions.     

GABAergic neurones in the rat periaqueductal grey matter express alpha4, beta1 and delta GABAA receptor subunits: plasticity of expression during the estrous cycle

Immunoreactivity for alpha4, beta1 and delta GABAA receptor subunits on neurones in the periaqueductal gray matter was investigated at different stages of the estrous cycle in Wistar rats. Immunostaining for alpha4, beta1 and delta GABAA receptor subunits was present on neurones throughout the periaqueductal gray matter. The numbers of subunit-immunoreactive neurones remained constant during the early phases of the estrous cycle (proestrus to early diestrus) but increased significantly in late diestrus. Dual immunolabeling for the GABA synthesizing enzyme glutamic acid decarboxylase revealed that almost 90% of the subunit-positive cells contained immunoreactivity for glutamic acid decarboxylase. During the early phases of the estrous cycle (proestrus to early diestrus), approximately one third of the glutamic acid decarboxylase-positive population co-localized alpha4, beta1 and delta GABAA receptor subunits. When the number of subunit positive cells increased during late diestrus, the proportion of the glutamic acid decarboxylase-containing population that expressed alpha4, beta1 and delta GABAA receptor subunits almost doubled. We propose that GABAA receptors with the alpha4beta1delta configuration are expressed by GABAergic neurones in the periaqueductal gray matter and that the numbers of cells expressing these subunits are increased in late diestrus in line with falling plasma progesterone levels. Changes in GABAA receptor expression may lead to changes in the excitability of the neural circuitry in the periaqueductal gray matter.     

Immunohistochemical studies of localization and co-localization of glutamate, aspartate and GABA in the anterior thalamic nuclei, retrosplenial granular cortex, thalamic reticular nucleus and mammillary nuclei of the rat

Localization and possible co-localization of glutamate, aspartate and GABA immunoreactivities was examined in the anterior thalamic nuclei, retrosplenial granular cortex, thalamic reticular nucleus and mammillary nuclei of the rat by double antigen immunohistochemistry using diaminobenzidine and benzidine dihydrochloride in one series and double immunofluorescence labelling with rhodamine and fluorescein in a second series of animals. In three of these regions, retrosplenial granular cortex, anterior thalamic nuclei, and mammillary nuclei, glutamate immunoreactivity was co-localized with aspartate immunoreactivity in a majority of the projection neurons (pyramidal neurons, predominantly in layers V and VI in retrosplenial granular cortex; rounded polygonal multipolar neurons throughout the rostrocaudal extent of the anterior thalamic and mammillary nuclei). None of the cells showing glutamate and/or aspartate immunoreactivity in these regions also displayed GABA immunoreactivity, which was present in non-pyramidal cells in the retrosplenial granular cortex (chiefly in layers I–III) and in small numbers of cells within the anterior thalamic nuclei. In the thalamic reticular nucleus, in contrast, most neurons were immunoreactive for GABA and in the majority of these neurons glutamate (and/or aspartate) immunoreactivity was co-localized with GABA.     

The thalamus of the Amazon spiny rat Proechimys guyannensis,an animal model of resistance to epilepsy,and pilocarpine-induced long-term changes of protein expression

The thalamus of the spiny rat Proechimys guyannensis (casiragua), a common rodent of the Amazon basin, was investigated with immunohistochemistry, using as markers GABA and glutamic acid decarboxylase, and calcium binding proteins. As in all mammals, GABAergic neurons containing also parvalbumin filled the reticular nucleus, and GABAergic cells were seen in the dorsal lateral geniculate nucleus. At variance with the laboratory rat, GABAergic and parvalbumin-containing neurons were also seen in the laterodorsal and anterodorsal nuclei, in which the two markers were co-distributed. Calbindin-immunopositive cells were widely distributed in dorsal thalamic domains, except for the intralaminar nuclei, and prevailed in the laterodorsal nucleus. The distribution of calretinin-immunopositive neurons was more restricted, and they were especially concentrated in the laterodorsal and midline nuclei.At variance with the laboratory rat, in which systemic pilocarpine administration induces status epilepticus and results in chronic limbic epilepsy, pilocarpine elicited in casiragua an acute seizure that was not followed by spontaneous seizures up to 1 month, when changes were evaluated in the thalamus using also image analysis. Parvalbumin immunostaining in reticular nucleus neurons and in the dorsal thalamus neuropil, and the number of parvalbumin-positive and GABAergic cells in the laterodorsal and anterodorsal nuclei, exhibited an increase with respect to controls. Calbindin immunostaining was also enhanced, whereas calretinin immunostaining was mostly reduced, but was preserved in midline neurons. The findings show, after an acute seizure induced in an animal model of anti-convulsant mechanisms, regional long-term neurochemical alterations that could reflect functional changes in inhibitory and excitatory thalamic neurons.     

GABAergic interneurons and neuropil of the intralaminar thalamus: an immunohistochemical study in the rat and the cat,with notes in the monkey

Summary Immunohistochemistry using antibodies to glutamic acid decarboxylase (GAD) was used to investigate the intralaminar nuclei of the thalamus in rat, cat and monkey. Antibodies to gamma aminobutyric acid (GABA) were also used in the cat. Intralaminar immunoreactive cell bodies were not detected in the rat, but were clearly present in cat and monkey. In the latter species, GABA- or GAD-immunopositive perikarya were distributed throughout the anterior intralaminar nuclei, whereas in the posterior intralaminar complex they prevailed in the lateral part of the centre median nucleus and around the fasciculus retrofiexus. Measurements of the area of immunostained intralaminar cell bodies in cat and monkey indicated that they are represented by small neurons. Experiments in the cat, based on retrograde tracers injections involving large sectors of the frontal and parietal cortices and the head of the caudate nucleus, revealed that the GABA- or GAD-immunoreactive cells and the retrogradely labeled projection neurons represented two separate intralaminar cell populations, although the latter also included small cells. Considerable differences were observed in the immunoreactive GABAergic neuropil of the anterior and posterior intralaminar nuclei. Clusters of densely packed bouton-like immunoreactive elements were detected in the former structures in the rat, cat and monkey, and were especially evident in the central lateral nucleus; immunopositive varicose fibers and puncta were diffusely distributed in the posterior intralaminar structures. Taken together with data from the literature, the present findings indicate that in cat and monkey local circuit inhibitory cells regulate not only the activity of principal thalamic nuclei which project densely upon restricted cortical fields, but also of the intralaminar structures which are widely connected with the cerebral cortex and the striatum. Regional variations in the distribution of GABAergic fibers and terminals suggest major differences in the organization of inhibitory circuits and synaptic arrangements of the anterior and posterior intralaminar thalamus.Abbreviations CeM central medial nucleus - CL central lateral nucleus - CM-Pf centre median-parafascicular complex - fr fasciculus retrofiexus - Hb habenular complex - LD laterodorsal nucleus - LP lateroposterior nucleus - MD mediodorsal nucleus - Pc paracentral nucleus - PO thalamic posterior complex - PvA anterior paraventricular nucleus - Sm stria medullaris - VL ventral lateral nucleus - VP ventroposterior complex     

The differential expression patterns of messenger RNAs encoding K-Cl cotransporters (KCC1,2) and Na-K-2Cl cotransporter (NKCC1) in the rat nervous system.

Cation-chloride cotransporters have been considered to play pivotal roles in controlling intracellular and extracellular ionic environments of neurons and hence controlling neuronal function. We investigated the total distributions of K-Cl cotransporter 1 (KCC1), KCC2 (KCC2), and Na-K-2Cl cotransporter 1 (NKCC1) messenger RNAs in the adult rat nervous system using in situ hybridization histochemistry. KCC2 messenger RNA was abundantly expressed in most neurons throughout the nervous system. However, we could not detect KCC2 messenger RNA expression in the dorsal root ganglion and mesencephalic trigeminal nucleus, where primary sensory neurons show depolarizing responses to GABA, suggesting that the absence of KCC2 is necessary for this phenomenon. Furthermore, KCC2 messenger RNA was also not detected in the dorsolateral part of the paraventricular nucleus, dorsomedial part of the suprachiasmatic nucleus, and ventromedial part of the supraoptic nucleus where vasopressin neurons exist, and in the reticular thalamic nucleus. As vasopressin neurons in the suprachiasmatic nucleus and neurons in the reticular thalamic nucleus produce their intrinsic rhythmicity, the lack of KCC2 messenger RNA expression in these regions might be involved in the genesis of rhythmicity through the control of intracellular chloride concentration. The expression levels of KCC1 and NKCC1 messenger RNAs were relatively low, however, positive neurons were observed in several regions, including the olfactory bulb, hippocampus, and in the granular layer of the cerebellum. In addition, positive signals were seen in the non-neuronal cells, such as choroid plexus epithelial cells, glial cells, and ependymal cells, suggesting that KCC1 and NKCC1 messenger RNAs were widely expressed in both neuronal and non-neuronal cells in the nervous system.These results clearly indicate a wide area- and cell-specific variation of cation chloride cotransporters, emphasizing the central role of anionic homeostasis in neuronal function and communication.     

The suprachiasmatic nucleus of the golden hamster: immunohistochemical analysis of cell and fiber distribution

The distribution of vasopressin-, vasoactive intestinal polypeptide-, somatostatin-, avian pancreatic polypeptide-, 5-hydroxytryptamine- and glutamic acid decarboxylase-like immunoreactivity was analyzed in the suprachiasmatic nuclei of male and female golden hamsters. Vasopressin. Vasopressin-like immunoreactivity is localized within neurons, dendrites and axons throughout the rostrocaudal extent of the suprachiasmatic nuclei. Immunoreactive perikarya are restricted to the dorsomedial aspect of each nucleus and occur in highest numbers within the intermediate two-thirds of the rostrocaudal axis. Axons containing vasopressin-like immunoreactivity form a dense plexus in the dorsomedial suprachiasmatic nuclei and in a vertical column at the lateral aspect of each nucleus. Somatostatin. Somatostatin-like immunoreactivity is also contained in neurons in the dorsomedial aspect of the suprachiasmatic nuclei and in thin varicose axons distributed throughout the suprachiasmatic nuclei in a pattern similar to that of vasopressin-immunoreactive axons. Vasoactive intestinal polypeptide. Vasoactive intestinal polypeptide-immunoreactive neurons are concentrated in the ventrolateral portion of each nucleus and occur almost exclusively within the intermediate two-thirds of the rostrocaudal axis. An extremely dense plexus of varicose axons exhibiting vasoactive intestinal polypeptide-like immunoreactivity extends throughout the suprachiasmatic nuclei and passes out of the dorsal aspect of each nucleus into the periventricular and anterior hypothalamic areas. Avian pancreatic polypeptide. Avian pancreatic polypeptide-like immunoreactivity is restricted to axons which arborize within the ventrolateral aspect of each nucleus. These fibers extend throughout the rostrocaudal extent of each nucleus and partially overlap the terminal field of retinal afferents. Glutamic acid decarboxylase. A very dense plexus of axonal varicosities exhibiting glutamic acid decarboxylase-like immunoreactivity fills both the dorsomedial and ventrolateral portions of the suprachiasmatic nuclei throughout the rostrocaudal extent of each nucleus. Lightly stained immunoreactive perikarya also occur throughout the suprachiasmatic nuclei. 5-Hydroxytryptamine. 5-Hydroxytryptamine-like immunoreactivity is restricted to axons which form a plexus in the ventromedial portion of each nucleus that is most dense in the intermediate two-thirds of the rostrocaudal axis.(ABSTRACT TRUNCATED AT 400 WORDS)     

Ca/calmodulin-dependent protein kinase II in the rat cerebellum: An immunohistochemical study with monoclonal antibodies specific to either α or β subunit

Monoclonal antibodies specific to either α or β subunit of Ca²⁺/calmodulin-dependent protein kinase II (CaM kinase II) of the rat brain were produced and the distribution of each subunit in the rat cerebellum was examined immunohistochemically. Each antibody detected solely the corresponding subunit in immunoblot analysis of crude homogenates of the rat forebrain and cerebellum, and purified CaM kinase II from the rat forebrain. Immunoreactivity for α subunit was present selectively in Purkinje cells: perikarya, dendrites with their spines, axons and their terminal-like structures in the cerebellar cortex, cerebellar nuclei and lateral vestibular nucleus. Many of these α subunit-immunoreactive axons from the cerebellum were traced only through the inferior cerebellar peduncle. β Subunit was detected in perikarya and dendrites of a limited number of Purkinje cells, many granule cells and neurons in the cerebellar nuclei. Thus, different distributions of α and β subunits of CaM kinase II in the cerebellum were demonstrated.     

Neural elements containing glutamic acid decarboxylase (GAD) in the dorsal lateral geniculate nucleus of the rat; immunohistochemical studies by light and electron microscopy

Immunoreactive constituents of the dorsal lateral geniculate nucleus of adult albino rats were examined by light- and electron-microscopy, using the unlabelled antibody enzyme method, following treatment of brain slices with a purified antibody to glutamic acid decarboxylase. The neuropil of the dorsal lateral geniculate nucleus displayed a conspicuous granular immunoreactivity. In addition, the antibody was bound to a class of small neurons of characteristic morphology. These cells possessed few (commonly 2-4) sparsely branched, long dendrites from some of which immunoreactive appendages were traced. Many cells were bipolar in form, and the dendrites of some appeared to be preferentially orientated. The immunoreactive cells closely resembled intrinsic interneurons characterized in previous Golgi studies of this nucleus. By electron-microscopy, immunoreactive presynaptic elements were present both in the extraglomerular neuropil and in the synaptic glomeruli. The former were axon terminals containing flattened synaptic vesicles and making Gray type II axo-dendritic synaptic contact; they appeared to correspond to axon terminals whose origin in the thalamic reticular nucleus has been established in previous studies, but it is possible that some were axon terminals of intrinsic interneurons. The immunoreactive glomerular components also contained flattened vesicles, were presynaptic to presumptive projection cell dendrites, postsynaptic to retinal axon terminals, and participated in triplet (triadic) and other complex synaptic arrangements. They corresponded in all respects to the synaptic portions of the complex dendritic appendages of intrinsic interneurons, identified and characterized in previous studies. The finding that there are high levels of glutamic acid decarboxylase in the cell bodies, dendritic shafts and dendritic appendages of intrinsic interneurons in the dorsal lateral geniculate nucleus of the rat, and in the axon terminals of fibres projecting to this site from the thalamic reticular nucleus, allows us to conclude that the inhibitory inputs to the geniculo-cortical projection cells from both of these sources are probably mediated by gamma-aminobutyric acid.     

RAM7,一种新的核蛋白分子在小鼠中枢神经系统的表达

Notch信号途径参与动物多种组织和器官尤其是神经系统的发育调节。 RBP-Jκ是 Notch信号途径中的关键分子 ,RAM7是近年通过酵母双杂交技术发现的与 RBP-Jκ相互作用的蛋白。本实验表达 RAM7C-末端 60 k D的多肽片段 ,并制备特异性的多克隆抗体 ,检测 RAM7在小鼠中枢神经系统的分布。结果显示 :RAM7主要呈细胞核染色 ,在中枢神经系统中广泛分布 ;尾壳核、丘脑室旁核、下丘脑室旁核、室周核等核团内没有 RAM7阳性神经元 ,但存在着一定数量的 RAM7阳性神经纤维 ;另有相当多 RAM7胞浆染色的细胞和神经元以及一些胶质细胞 ,局限在脑室和脑室周围的神经组织中。RAM7分子的分布对其可能的生理功能有一定的提示作用