bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neocortex and hippocampus contain distinct distributions of calcium‐calmodulin protein kinase II and GAP43 mRNA
Authors: Jacobs Kimberle M. , Neve Rachael L. , Donoghue John P. 
Published: January 2005

AbstractCalcium‐calmodulin protein kinase II and GAP43 are two molecules which have been linked to synaptic plasticity. Localization of mRNA for these molecules identifies the neuronal populations which have the potential to utilize these mechanisms. General descriptions for calcium‐calmodulin protein kinase II or GAP43 mRNA have been previously reported. In light of recent evidence that suggests that at some sites these two molecules may interact, we sought to determine the cortical distribution in detail, and to examine the extent of overlap between neuronal populations containing each mRNA. To this end we have used in situ hybridization techniques to study the distribution of calcium‐calmodulin protein kinase II and GAP43 mRNA in adjacent sections of adult rat forebrain. Overall, the distribution patterns were distinct but partially overlapping. For both calcium‐calmodulin protein kinase II and GAP43, mRNA levels were highest in hippocampus, allo‐ and neocortex, compared to moderate to low levels in striatum and thalamic nuclei. Within the heavily labeled regions certain populations expressed both calcium‐calmodulin protein kinase II and GAP43 mRNA at high levels, while other populations were selective for calcium‐calmodulin protein kinase II. In the hippocampus, the stratum pyramidale of CAI‐3 expressed high levels of both calcium‐calmodulin protein kinase II and GAP43 mRNA. Granule cells of the fascia dentata and the stratum radiatum of CA3 both contained moderate to high levels of calcium‐calmodulin protein kinase II mRNA, but near background levels of GAP43 mRNA label. Within the neocortex, deep layers were distinguished from superficial layers by their lack of calcium‐calmodulin protein kinase II mRNA expression within the neuropil, and the presence of GAP43 mRNA in neurons located in layer V and the deepest part of layer VI. Thus, layer V and deep layer VI neurons showed high levels of label for both GAP43 and calcium‐calmodulin protein kinase II mRNA, while neurons of superficial layers contained only calcium‐calmodulin protein kinase II mRNA. These markers differentiate neuronal populations which can also be distinguished on the basis of their ability to undergo specific forms of synaptic plasticity. These different forms of plasticity may be due in part to the laminar‐specific patterns of GAP43 and calcium‐calmodulin protein kinase II mRNA that we have described. © 1993 Wiley‐Liss, Inc.
Cytoarchitecture of spinal‐projecting neurons in the brain of the larval sea lamprey
Authors: Swain Gary P. , Snedeker Joseph A. , Ayers Joseph , Selzer Michael E. 
Published: January 2005

AbstractThe descending spinal projecting system of the lamprey is of interest because it includes axons that activate swimming pattern generatorsand because regeneration of this system is involved in the behavioral recovery of lampreys following spinal transection. However, little is known about the true size of this projection and of the distribution of its terminations along the spinal cord. Brain neurons with spinal projections were studied in larval sea lampreys by using wholemount preparations labeled retrogradely with horseradish peroxidase (HRP) from spinal injections at 10%, 15%, 25%, 50%, 70%, and 75% of body length from the anterior end. Neurons projecting to different levels of the spinal cord were mapped. A large number of descending axons terminated within nine segments caudal to the last gill. The spinal projection system was divided into 10 bilateral groups based on cytoarchitectural landmarks. All of the lateral nuclear groups had contralateral spinal projections. In addition to the 12 pairs of Müller cells, the pair of Mauthner cells, and the pair of auxiliary Mauthner cells described by previous authors, the study revealed four pairs of smaller neurons that were individually identifiable. © 1993 Wiley‐Liss, Inc.
Synaptic relationships involving local axon collaterals of pyramidal neurons in the cat motor cortex
Authors: Keller Asaf , Asanuma Hiroshi 
Published: January 2005

AbstractThe intracortical synaptic relationships of pyramidal neurons in the cat motor cortex were studied by intracellular recording and labeling techniques. Neurons that responded with monosynaptic excitatory postsynaptic potentials (EPSPs) to microstimulation in the somatosensory cortex were identified by intracellular recordings. Long‐term potentiation (LTP) was evoked in all of these neurons (n = 15), following tetanic stimulation (50 Hz, 5 s) of their afferents from the somatosensory cortex. Three of these cells (cells A‐C) were identified as pyramidal neurons, following intracellular injections of Neurobiotin. The intracortical axon collaterals of these labeled cells arborized extensively, forming terminal clusters both in clse proximity to the parent soma and along their long, horizontal branches. Terminal clusters in both the proximal and in the distal termination zones of each of the cells were studied by electron microscopy. In their proximal arborization zones, the axon collaterals of the labeled pyramidal neurons synapsed preferentially with dendritic spines belonging to other pyramidal cells. In contrast, in their distal terminal clusters, the axon collateals of each of the cells formed synapses in different proportions with different postsynaptic targets. The distal axon collaterals of cell A formed 86% of their synapses with pyramidal neurons; those of cell B formed 64% of their synapses with pyramidal cells, the remaining synapses with the dendritic shafts and somata of nonpyramidal neurons, and those of cell C provided most of their output (68%) to nonpyramidal, presumably inhibitory neurons. These findings suggest a high selectivity of intrinsic axon collaterals to form specific patterns of synapses. The patterns of synaptic interactions formed by these intrinsic axon collaterals may be a substrate for shaping and modulating representation maps in the motor cortex. © 1993 Wiley‐Liss, Inc.
Cholinergic innervation of olfactory glomeruli in the rat: An ultrastructural immunocytochemical study
Authors: Jeune Hélène Le , Jourdan François 
Published: January 2005

AbstractThe ultrastructural organization of cholinergic afferents to the rat olfactory bulb (OBI) was studied with the aid of choline acetyltransferase (ChAT) immunocytochemistry in electron microscopy. Particular attention has been paid to a subset of glomeruli characterized by a remarkably high density of cholinergic afferents. Numerous cholinergic terminals making symmetric or asymmetric synaptic contacts were observed in the periglomerular area. ChAT‐labelled terminals have a diameter ranging from 0.3 to 1.5 μm and contain numerous clear agranular vesicles. Axo‐somatic and axo‐dendritic contacts were both observed in contact with several types of target neurons. Three types of cholinoceptive, noncholinergic neurons could be identified: periglomerular cells, superficial short‐axon cells, and external tufted cells. Our results provide an anatomical substrate for the hypotheses concerning the complex effects of acetylcholine in the processing of sensory information in the olfactory bulb. © 1993 Wiley‐Liss, Inc.
Immunolocalization of different forms of neural cell adhesion molecule (NCAM) in rat taste buds
Authors: Nelson Gina M. , Finger Thomas E. 
Published: January 2005

AbstractTaste buds consist of approximately 100 taste cells, including three morphological types of short receptor cells which synapse on the peripheral gustatory nerves. Some of the receptor cells produce neural cell adhesion molecule (NCAM), which may play a role in formation of specific connections in this system. Antibodies directed against different forms of NCAM were utilized in an attempt to define not only the distribution, but also the type of NCAM within taste buds.Within each taste bud approximately 10% of the taste cells exhibit abundant immunoreactivity for 180 kD (ld) or 140 kD (sd) forms of NCAM (i.e., those with an intracellular domain) along virtually the entire surface of the cell. Ultrastructural analysis reveals that these abundantly immunoreactive taste cells are of the intermediate morphological type, although not all of the intermediate taste cells within any bud are immunoreactive. In addition, the ultrastructural studies show that punctate (ld/sd) NCAM‐immunoreactivity occurs on the membranes of taste cells and nerve fibers throughout each taste bud. The embryonic form of NCAM (E‐NCAM), rich in polysialic acid residues, is present only in association with nerve fibers and other unidentified elongate, thin profiles of a few taste buds.The nerve plexus beneath the gustatory epithelium is also rich in NCAM‐immunoreactivity. These fibers occasionally reveal immunoreactivity indicative of only the 120 kD (ssd) form of NCAM, typical of glial cells. © 1993 Wiley‐Liss, Inc.
Presence and biological activity of a GnRH‐like factor in the nervous system of Helisoma trivoluis
Authors: Goldberg Jeffrey I. , Garofalo Rafe , Price Christopher J. , Chang John P. 
Published: January 2005

AbstractGonadotropin‐releasing hormone (GnRH) constitutes a family of neuropeptides found throughout the vertebrates. Although a GnRH‐like peptide has also been isolated from yeast (α‐mating factor), the presence of GnRH has not been clearly demonstrated in inverterate phyla. In this study, we tested the hypothesis that GnRH‐like peptides are present and functional in the central nervous system (CNS) of the gastropod mollusc, Helisoma trivoluis. The presence of a GnRH‐like peptide was examined by three methods: (1) in immunofluorescence studies with four different antibodies generated against several GnRH peptides, select neurons and putative neurosecretory cells were specifically and consistently labelled throughout the CNS; (2) reverse‐phase high performance liquid chromatography (HPLC) and radioimmunoassay (RIA) analysis revealed a GnRH‐like factor which co‐migrates with mammalian (m)GnRH; and (3) in bioactivity experiments, extracts of Helisoma trivolvis CNS mimicked GnRH in stimulating gonadotropin release from dispersed goldfish pituitary cells in static culture.Two functional assays were carried out to examine the potential biological roles of GnRH‐like peptides in Helisoma. (1) Intracellular recordings of left‐parietal and visceral ganglion neurons revealed diverse electrophysiological responses to mGnRH. These effects were attenuated by a mGnRH antagonist. (2) Addition of mGnRH arrested neurite outgrowth in a subpopulation of dissociated embryonic Helisoma neurons in culture. Taken together, these results strongly suggest that a mGnRH‐like peptide is an important neuropeptide in Helisoma. A hypothesis is presented that GnRH‐like peptides may be ancient factors that are conserved both structurally and functionally in the evolution of animals. © 1993 Wiley‐Liss, Inc.
Pigment‐dispersing hormone‐immunoreactive neurons in the nervous system of wild‐type Drosophila melanogaster and of several mutants with altered circadian rhythmicity
Authors: Helfrich‐Förster Charlotte , Homberg Uwe 
Published: January 2005

AbstractAntisera against the crustacean pigment‐dispersing hormone (β‐PDH) were used in immunocytochemical preparations to investigate the anatomy of PDH‐immunoreactive neurons in the nervous system of wild‐type Drosophila melanogaster and in that of several brain mutants of this species, some of which express altered circadian rhythmicity. In the wild‐type and in all rhythmic mutants (small optic lobes, sine oculis, small optic lobes;sine oculis), eight cell bodies at the anterior base of the medulla (PDFMe neurons) exhibit intense PDH‐like immunoreactivity. Four of the eight somata are large and four are smaller. The four large PDFMe neurons have wide tangential arborizations in the medulla and send axons via the posterior optic tract to the contralateral medulla. Fibers from the four small PDFMe neurons ramify in the median protocerebrum dorsal to the calyces of the mushroom bodies. Their terminals are adjacent to other PDH‐immunoreactive somata (PDFCa neurons) which send axons via the median bundle into the tritocerebrum. The results suggest a possible involvement of the PDFMe neurons in the circadian pacemaking system of Drosophila. The location and size of the PDFMe neurons are identical with those of neurons containing the period protein which is essential for circadian rhythmicity. Changes in the arborizations of the PDFMe neurons in small optic lobes; sine oculis mutants are suited to explain the splitting in the locomotor rhythm of these flies. In the arrhythmic mutant, disconnected, the PDFMe neurons are absent. The arrhythmic mutant per°, however, shows normal PDH immunoreactivity and therefore, does not prevent the expression of PDH‐like peptides in these neurons.© 1993 Wiley‐Liss, Inc.
Nerve innervation of the hand and associated nerve dominance aggregates in the somatosensory cortex of a primate (squirrel monkey)
Authors: Wall John T. , Nepomuceno Vincent , Rasey Sandra K. 
Published: January 2005

AbstractThe cutaneous innervation territories of the median, ulnar, and radial nerves to the hand were determined from neurophysiological recordings of peripheral mechanoreceptor axons in adult squirrel monkeys. These territories were then related to cutaneous receptive fields of cortical area 3b neurons to determine how low‐threshold inputs from each hand nerve map onto the primary somatosensory cortex.The results indicate that mechanoreceptor axons in each nerve innervate a continuous skin territory covering about 40% of the hand surface. The total territory of each nerve contains subregions of skin that are either autonomously innervated by that nerve or that receive overlapping innervation from more than one nerve. The autonomous, overlap, and total territories of each nerve are relatively constant from hand to hand. In the area 3b cortex, low‐threshold afferents from each nerve provide inputs to aggregates of cortical neurons. The cortical aggregates relating to the median and ulnar nerves are arranged as continuous, rostrocaudally oriented bands, whereas aggregates relating to the radial nerve are discontinuous and more patchlike. Similar patterns of bands and patches, and similar compression ratios of skin/cortical area, are seen across different monkeys.These findings demonstrate that the primary somatosensory cortex of normal adult primates contains bands or patches of neurons that are dominantly activated by low‐threshold inputs from specific hand nerves. This approach of delineating nerve territories and their related cortical dominance aggregates provides a useful means of analyzing cortical images of nerves and of quantitating peripheral and central patterns of deprivation after nerve injury. © 1993 Wiley‐Liss, Inc.
FMRFamide‐like activity in the female locust during vitellogenesis
Authors: Sevala V. M. , Sevala V. L. , Loughton B. G. 
Published: January 2005

AbstractThe control of oviposition in the locust involves the expulsion of eggs from the lateral oviducts, a process believed to be under neurohormonal control. In this paper we have attempted to identify this putative hormone. Immunohistochemical staining of the brain retrocerebral complex and suboesophageal ganglion of Locusta migratoria with antiserum against FMRFamide revealed a number of FMRFamide‐immunopositive cells. FMRFamide‐like immunoreactivity was present in median neurosecretory cells and lateral neurosecretory cells of the protocerebrum. Other FMRFamide‐immunoreactive cells were detected in the deutocerebrum and tritocerebrum. Immunoreactive cell processes were observed in the mushroom bodies, the central body, the optic lobes, and in the axon tracts leaving the pars intercerebralis and tritocerebrum. FMRFamide‐like material was also seen in the circumoesophageal commissures. Further FMRFamide‐like material was present in cell bodies of the suboesophageal ganglion. FMRFamide‐like staining activity changed dramatically during the oviposition cycle in mature adult females. The median neurosecretory cells stained lightly immediately after oviposition and remained pale until the third day, when staining of perikarya and axon tracts increased. The staining intensity decreased on days 4 and 5. The titre of FMRFamide‐like material in the hemolymph increased during the vitellogenic cycle but plummeted after oviposition. A single band of FMRFamide‐like material was evident on immunoblot following sodium dodecyl sulphate‐polyacrylamide gel electrophoresis of adult female hemolymph. The approximate molecular weight of this molecule was 8,000. Gel permeation chromatography of hemolymph revealed a FMRFamide‐immunoreactive fraction with a molecular weight of 8,000. This fraction possessed myotropic activity when applied to the locust oviduct. It is argued that this molecule functions as an oviposition hormone in the locust.© 1993 Wiley‐Liss, Inc.
Direct projections from the anterior thalamic nuclei to the retrohippocampal region in the rat
Authors: Shibata Hideshi 
Published: January 2005

AbstractThe present study examined the areal and laminar distribution of direct projections from the anterior thalamic nuclei to the retrohippocampal region in the rat, with anterograde transport of Phaseolus vulgaris‐leucoagglutinin. The anteromedial nucleus (AM) projects to the temporal subiculum, medial entorhinal area, perirhinal area, and caudomedial part of the lateral entorhinal area. The interanteromedial nucleus (IAM) projects to the perirhinal area 0and the caudolateral part of the lateral entorhinal area. Furthermore, both the AM and IAM project to the temporal area 2, occipital area 1, and lateral occipital area 2. The projections from the AM and IAM to these retrohippocampal and neocortical regions terminate mainly in deep layers. The anteroventral nucleus (AV) projects to the subicular complex with a complex topographic organization. The most rostral part of the AV projects to layers I and III of the ventral presubiculum, the pyramidal cell layer of the temporal subiculum, and deep layers of the parasubiculum and medial entorhinal area. At the midrostrocaudal level of the AV, the lateral and the dorsal quadrants of the AV project, respectively, to layers I and III and to layers I and IV–VI of the ventral presubiculum, whereas the ventral and the medial quadrants project, respectively, to layers I and III and to layers I and IV–VI of the dorsal presubiculum. Furthermore, the lateral and dorsal quadrants project to the pyramidal cell layer of the temporal subiculum, whereas the ventral and medial quadrants project more septally. At the caudal third level of the AV, the dorsolateral part projects to layers I and III of the presubiculum with a patchy pattern and to the pyramidal cell layer of the septal subiculum. The anterodorsal nucleus projects mainly to deep layers of the presubiculum, parasubiculum, and entorhinal area. The results show that each subdivision of the anterior thalamic nuclei projects to a distinct field in the retrohippocampal region. This suggests that each of these projections may have a distinct modulatory influence upon the activity of retrohippocampal neurons that play important roles in limbic functioning such as memory and learning proceses. © 1993 Wiley‐Liss, Inc.
Secondary olfactory projections and pallial topography in the pacific hagfish, Eptatretus stouti
Authors: Wicht Helmut , Northcutt R. Glenn 
Published: January 2005

AbstractThe extent of the secondary olfactory projections shows great variation among different groups of craniates. Gnathostomes typically display restricted secondary olfactory projections, whereas lampreys have more extensive projections. Any attempt to determine the phylogenetic polarity of these characters, that is, to decide which is primitive and which is derived, requires an investigation of the secondary olfactory system in the sister group of lampreys and gnathostomes, the hagfishes. Therefore the secondary olfactory projections of the Pacific hagfish, Eptatretus stouti, were traced with the use of horseradish peroxidase and the lipophilic fluorescent tracing compound Dil. The projections are bilateral and massive to all pallial areas and the septum, moderate to the striatum, and relatively weak to the preoptic and infundibular regions of the hypothalamus, reaching caudally to the diencephalic‐mesencephalic boundary. Afferents to the olfactory bulb arise from the pallium, the preoptic area, and the ventral thalamus. We compare the secondary olfactory projections in hagfishes with those in lampreys and in gnathostomes, and we conclude that the presence of extensive secondary olfactory projections is a primitive character of craniate brains. © 1993 Wiley‐Liss,Inc.
Comparative distribution of mammalian GnRH (gonadotrophin‐releasing hormone) and chicken GnRH‐II in the brain of the immature siberian sturgeon (Acipenser baeri)
Authors: Leprêtre Emmanuel , Anglade Isabelle , Williot Patrick , Vandesande Frans , Tramu Gérard , Kah Olivier 
Published: January 2005

AbstractThe brain of the sturgeon has recently been shown to contain at least two forms of GnRH (gonadotropin‐releasing hormone), mammalian GnRH (mGnRH) and chicken GnRH‐II (cGnRH‐II). In this study, we compared the distribution of immunoreactive (ir) mGnRH and cGnRH‐II in the brain of immature Siberian sturgeons (Acipenser baeri). The overall distribution of mGnRH was very similar to the distribution of sGnRH in teleosts such as salmonids or cyprinids. mGnRH‐ir perikarya were observed in the olfactory nerves and bulbs, the telencephalon, the preoptic region, and the mediobasal hypothalamus. All these cell bodies are located along a continuum of ir‐fibers that could be traced from the olfactory nerve to the nerve to the hypothalamopituitary interface. No ir‐fibers were observed in the anterior lobe of the pituitary, but a few were seen to enter the neurointermediate lobe. mGnRH‐ir fibers were detected in many parts of the brain, particularly in the forebrain. mGnRH‐ir cerebrospinal fluid‐containing cells were observed in the telencephalon, the preoptic region, and the mediobasal hypothalamus. In contrast, cGnRH‐II was present mainly in the posterior brain, although a few ir axons were seen in the above‐mentioned territories. In particular, cGnRH‐II‐ir cell bodies, negative for mGnRH, were consistently observed in the nucleus of the medial longitudinal fasciculus of the midbrain tegmentum. The cGnRH‐II innervation in the optic tectum, cerebellum, vagal lobe, and medulla oblongata was more abundant than the mGnRH innervation in the same areas. This study provides evidence that the organization of the GnRH systems in a primitive bony fish is, highly similar to that reported in teleosts and further documents the differential distribution of two forms of GnRH in the brain of vertebrates. © 1993 Wiley‐Liss,Inc.