bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution and morphology of synapses on nonspiking local interneurones in the thoracic nervous system of the locust
Authors: Watson A. H. D. , Burrows M. 
Published: May 2005

AbstractThe structure and distribution of synapses on nonspiking local interneurones in the metathoracic ganglion of the locust was revealed by electron microscopy following intracellular injection of horseradish peroxidase (HRP). Before staining, each interneurone was characterized physiologically as nonspiking and its output effects on motor neurones innervating muscles in a hindleg were investigated. Three nonspiking interneurones of different morphologies, each typical of a previously described population, were selected for detailed study. The first has a dorsal soma and ipsilateral neuropilar branches, the second a ventral soma and ipsilateral branches, and the third a ventral soma and contralateral branches. The somata have few trophospongial invaginations, and most of their volume is occupied by the nucleus. The initial parts of the primary neurites are either wrapped in glia or isolated in tracts from the neuropile and thus do not participte in synaptic interactions. Some of the larger secondary neurites are also wrapped in glia, but others both make and receive synaptic contacts. Output synapses have an array of some 500–1,600 round, agranular vesicles (diameter 47.0 ± 5.7 nm; mean ± S.D., n = 97) associated with a bar‐shaped presynaptic density up to 0.3 μm long. Two postsynaptic processes, whose diameter can vary greatly, are usually associated with each presynaptic density. Processes making input synapses onto nonspiking local interneurones typically contain round, agranular vesicles and often make several contacts within a few microns. Serial reconstructions from one of the interneurones revealed input and output synapses intermingled on the larger processes with outputs dominating by a factor of 3:1, whereas on some of the thinner processes only input synapses are present. In the other two interneurones, however, both input and output synapses are present on the fine branches. No feature of the structure or distribution of synapses observed here on the nonspiking local interneurones distinguishes them from spiking neurones in the same ganglia.
Interstitial cells of cajal in the canine colon: A special communication network at the inner border of the circular muscle
Authors: Berezin I. , Huizinga J. D. , Daniel E. E. 
Published: May 2005

AbstractThe ultrastructure of the region shown to be essential for pacemaking activity of the circular muscle of the canine colon was studied. This region, at the inner border of the circular muscle, consists of a network of several layers of interstitial cells of Cajal type III. These are interconnected to one another and to the adjacent circular muscle cells by numerous gap junctions. Elsewhere in circular muscle, gap junctions are rare and small. In addition, interstitial cells are in close (often < 20 nm) contact with nerve varicosities containing large granular vesicles or sometimes small granular vesicles. The morphology of interstitial cells resembles that of others of type III. It is suggested that this arrangement of interstitial cells, circular smooth muscles, and nerves allows for a tightly coupled network of membrane oscillators to be subject to neural modulation.
Distribution of calcitonin gene‐related peptide immunoreactivity in relation to the rat central somatosensory projection
Authors: Kruger Lawrence , Sternini Catia , Brecha Nicholas C. , Mantyh Patrick W. 
Published: May 2005

AbstractThe distribution of the neuropeptide calcitonin gene‐related peptide (CGRP) was studied in relation to the known subcortical somatosensory pathways and contiguous systems in the central nervous system (CNS) of rats by using peroxidase histochemical methods in order to relate zones of immunoreactivity (IR) to cytoarchitecture. CGRP is the most ubiquitous peptide found to date in sensory ganglion cells: principally small and medium‐size neurons emitting thin axons inferred to be largely nociceptive in function on the basis of the peripheral distribution of their terminals. Its apparent absence in sympathetic axons provides an especially useful sensory marker.The distribution of CGRP‐IR axons displays remarkable selectivity at each level of the CNS. The trigeminal root distributes axons primarily to the pericornual layers (laminae I and II) of spinal V nucleus caudalis and to subnucleus oralis, evading the subnucleus interpolaris and contributing only few axons to principal V. Although there are only a few CGRP‐IR somata at each level, heavily labeled axon trajectories can be traced to the nuclei of the solitary tract, the parabrachial nuclei, several sectors of the caudal medial thalamus, and the central nucleus of the amygdala. A sector of labeled neuron somata lies contiguous to each of these axon terminal zones, the largest of which is a thalamic nucleus containing cells of distinctive dendritic architecture extending from the periaqueductal gray across the posterior group nuclei to the peripeduncular nucleus, forming a linear array at the mesodiencephalic junction.The relation of CGRP‐IR axonal distribution to spinothalamic, visceral, and gustatory systems is discussed in the context of a specialized „chemosensory”︁ component of the thin‐fiber somatosensory system.
Catecholaminergic neurons in the ventrolateral medulla and nucleus of the solitary tract in the human
Authors: Arango Victoria , Ruggiero David A. , Callaway Janie L. , Anwar Muhammad , Mann J. John , Reis Donald J. 
Published: May 2005

AbstractCatecholaminergic neurons in the ventrolateral medulla (VLM) and nucleus of the solitary tract (NTS) are important because of their presumed roles in autonomic regulation, including the tonic and reflex control of arterial pressure, neuroendocrine functions, and the chemosensitivity associated with the ventral medullary surface. However, little is known about the connections of these neurons in the human brain. As a first step in analyzing the functional biochemical anatomy of catecholamine neurons in the human, we used antisera against tyrosine hydroxylase (TH) and phenylethanolamine N‐methyltransferase (PNMT) to localize medullary catecholamine‐containing neurons and processes in the VLM and the NTS.Cells staining for TH were located throughout the VLM. Most cells staining for TH and PNMT, which are therefore adrenergic, occurred in an area of the VLM probably corresponding to the rostroventrolateral reticular nucleus. Axons of TH‐immunoreactive neurons in the VLM projected (1) dorsally, in a series of parallel transtegmental trajectories, toward the dorsomedial reticular formation, the NTS, and vagal motor nucleus, (2) longitudinally, through the central tegmental field, as fascicles running parallel to the neuraxis, (3) ventrolaterally toward the ventral surface (VS) of the rostral VLM where they appeared to terminate, and (4) medially into the raphe, where they arborized. Similar systems of fibers were labeled for PNMT; the longitudinal bundles of PNMT‐labeled axons were limited to the principal tegmental bundle and concentrated dorsally. Fibers containing PNMT were also identified in the medullary raphe, on the medullary ventral surface, and contacting intraparenchymal blood vessels. In the NTS, neurons exhibited immunoreactivity to both TH and PNMT: Four principal subgroups of TH‐immunoreactive neurons were seen: a ventral, an intermediate, a medial, and a dorsal group. Perikarya containing PNMT were restricted to the dorsolateral aspect of the NTS. Processes containing TH and PNMT immunoreactivity were identified in the medial and dorsolateral NTS; others appeared to project between the NTS and the VLM and within the solitary tract.The presence of catecholaminergic fibers of the VLM interconnecting with the NTS, raphe, intraparenchymal microvessels, VS, and possibly the spinal cord suggests that the autonomic and chemoreceptor functions attributed to these neurons also may apply to the human.
Distribution of monoamine‐synthesizing neurons in the human medulla oblongata
Authors: Halliday G. M. , Li Y. W. , Joh T. H. , Cotton R. G. H. , Howe P. R. C. , Geffen L. B. , Blessing W. W. 
Published: May 2005

AbstractWe have employed immunohistochemical and morphometric procedures to study the distribution of monoamine‐synthesizing neurons in the medulla oblongata of the adult human, utilizing antibodies to tyrosine hydroxylase (TH), phenylethanolamine N‐methyltransferase (PNMT), and phenylalanine hydroxylase (PH8). In the human brain, the antigen with which PH8 reacts occurs within neurons that presumably synthesize serotonin (Haan et al., ′87). Neurons containing these antigens were mapped and counted in successive coronal sections with the aid of a computer‐assisted procedure. The results indicate that monoamine‐synthesizing neurons are distributed in the human brain in patterns broadly similar to those described for other species.TH‐immunoreactive cells extended caudorostrally for approximately 32 mm commencing at the spinomedullary junction and ending 8 mm caudal to the pontomedullary junction. In coronal sections these TH‐immunoreactive neurons were seen in the lateral medulla dorsal to the inferior olive extending in a continuous band to the dorsomedial medulla. Above the obex the majority of these cells apparently synthesize adrenaline since many PNMT‐immunoreactive cells were also found in this region. There were few or no PNMT‐immunoreactive cells caudal to the obex, indicating that the TH‐immunoreactive cells in this region synthesize either noradrenaline or dopamine. Approximately 65% of these TH‐immunoreactive neurons contained melanin pigment, whereas few or no PNMT‐immunoreactive cells contained melanin pigment.PH8‐immunoreactive cells extended throughout the rostrocaudal extent of the medulla oblongata (approximately 40 mm). In coronal sections the majority were found in the medullary raphe nuclei. However, many cells throughout the rostrocaudal extent of the medulla were found laterally intermingled with catecholamine‐synthesizing neurons. Occasional neurons in the lateral medulla appeared to contain both PH8‐ and TH‐immunoreactivity.
Immunocytochemical studies of the distribution of acetylcholine in the crayfish brain
Authors: Wang‐Bennett Lolin T. , Sovan Marie‐Laure , Glantz Raymon M. 
Published: May 2005

AbstractA number of studies indicate that acetylcholine is an important transmitter in most crustacean primary afferents and in at least several central pathways. Little is known, however, regarding the structure or distribution of cholinergio pathways in the central nervous system. The recent introduction of antibodies to choline‐protein conjugates provides a potentially powerful means for localizing putative cholinergic neurons and pathways in the nervous system. Acetylcholine was localized with immunocytochemical procedures in the axons and terminals of cephalic primary afferents and in interneurons of the crayfish brain. The most intensely reactive loci were the primary sensory neuropiles, which contain the terminals of the statocyst afferents (parolfactory lobes) and antennal afferents (antennal lobe). These results are generally in accord with previous findings based upon choline uptake and enzyme assay in lobster cephalic nerves. We also found evidence consistent with the presence of acetylcholine in the globular interneurons of the accessory lobe and in descending interneurons which originate in the dorsal medial and anterior clusters of the protocerebrum. The axons of several neurons in the circumesophageal connective (descending interneurons and primary afferents) are also reactive to the choline antibody.
Putative cholinergic projections from the nucleus isthmi and the nucleus reticularis mesencephali to the optic tectum in the goldfish (Carassius auratus)
Authors: Zottoli Steven J. , Rhodes Kenneth J. , Corrodi J. Gregory , Mufson Elliott J. 
Published: May 2005

AbstractThe nucleus isthmi of fish and amphibians has reciprocal connections with the optic tectum, and biochemical studies suggest that it may provide a major cholinergic input to the tectum. In goldfish, we have combined immunohistochemical staining for choline acetyltransferase with retrograde labeling of nucleus isthmi neurons after tectal injections of horseradish peroxidase.Seven fish received tectal horseradish peroxidase injections, and brain tissue from these animals was subsequently processed for the simultaneous visualization of horseradish peroxidase and choline acetyltransferase. In many nucleus isthmi neurons the dense horseradish peroxidase label obscured the choline acetyltransferase reaction product but horseradish peroxidase and choline acetyltransferase were colocalized in 54 cells from nine nuclei isthmi.The somata of nucleus reticularis mesencephali neurons stained so intensely for choline acetyltransferase that we could not determine whether they were labelled also with horseradish peroxidase. However, the large choline acetyltransferase‐immunoreactive axons of nucleus reticularis mesencephali neurons stained intensely enough for us to follow them rostrally; the axons are clustered together until the level of the rostral tectum where two groupings form: one travels into the tectum and the other travels rostroventrally to cross the midline and enter the contralateral diencephalic preoptic area.We conclude therefore that cholinergic neurons project to the optic tectum from the nucleus isthmi as well as nucleus reticularis mesencephali in goldfish.
Somatosensory and auditory relay nucleus in the rostral part of the ventrolateral medulla: A morphological study in the cat
Authors: Kamiya Hiroto , Itoh Kazuo , Yasui Yukihiko , Ino Tadashi , Mizuno Noboru 
Published: May 2005

AbstractA nucleus that possibly relays both somatosensory and auditory information was identified in the well‐known autonomic control region in the rostral part of the ventrolateral medulla (RVL) of the cat by four sets of experiments using the WGA‐HRP (wheat germ agglutinin—horseradish peroxidase conjugate) method. First, after injecting WGA‐HRP into the dorsal column nuclei (DCN), anterograde and retrograde labeling was found bilaterally within and around a small cluster of medium‐sized neurons in the RVL; more labeled neuronal cell bodies were seen in the cluster ipsilateral to the injection than in the contralateral cluster, whereas labeled axon terminals were distributed more densely on the contralateral side than on the ipsilateral side. The neuronal cluster in the RVL was located close to the ventrolateral surface of the medulla oblongata, constituting a short, slender column extending from a caudal level of the facial nucleus to the level of the rostral one‐third of the inferior olive. This cluster of neurons was named the ventrolateral medullary nucleus (VLMN).In the second set of experiments, WGA‐HRP was injected into the VLMN. Labeled neuronal cell bodies were seen in the reticular zone of the DCN bilaterally, with a slight dominance on the side contralateral to the injection, and further in the anteroventral division of the cochlear nuclei (CN) bilaterally, with a predominantly contralateral distribution. Labeled presumed axon terminals were seen bilaterally not only in the DCN and granular layer of the CN but also in the intercollicular region (IcR), lateral division of the posterior group of the thalamus (Pol), and medial geniculate nuclei (MG). Labeled terminals in the DCN were more numerous on the side ipsilateral to the injection than on the contralateral side, whereas those in other regions were distributed with a clear‐cut contralateral dominance.In the third set of experiments, WGA‐HRP injection into the CN resulted in anterograde and retrograde labeling in the VLMN. The labeling was bilateral, but more marked in the VLMN contralateral to the injection.In the fourth set of experiments, after WGA‐HRP injection into the IcR, Pol, or MG, labeled neuronal cell bodies were located in the VLMN bilaterally with a dominant contralateral distribution.The results indicate that the VLMN possibly relays somatosensory and auditory information from the reticular zone of the DCN and anteroventral division of the CN to the IcR, Pol, and MG.
Immunocytochemical localization of glutamate decarboxylase in the rat basolateral amygdaloid nucleus, with special reference to GABAergic innervation of amygdalostriatal projection neurons
Authors: Carlsen Jørn 
Published: May 2005

AbstractGlutamate decarboxylase (GAD) immunohistochemistry was employed at the light and electron microscopic levels to localize GABAergic structures in the basolateral amygdaloid nucleus (BL).The GAD‐immunoreactive (GAD‐IR) staining pattern consisted of punctate structures and a morphologically diverse group of GAD‐IR neurons. At the electron microscopic level many of these punctate structures were found to make symmetrical synaptic contacts with cell bodies as well as distal parts of unlabeled, presumably projection and nonprojection, neurons. In addition, GAD‐immunoreactive neurons were identified in the BL, and they had the ultrastructural characteristics of local circuit or intrinsic neurons and were not retrogradely labeled with HRP following ventral striatal injections. Some of these GAD‐immunoreactive neurons were contacted by GABAergic boutons, forming symmetrical synaptic contacts.GABAergic innervation of amygdaloid projection neurons in the BL was identified by combining GAD immunohistochemistry with Golgi impregnation and retrograde tracing of horseradish peroxidase (HRP) following injections of the tracer in the olfactory‐tubercle‐related parts of the ventral striatum. Amygdalostriatal projection neurons in the BL were observed to be in continuity with neurons in the piriform cortex which project to the ventral striatum. The results provide direct evidence for the presence of GAD‐IR boutons in the BL making synaptic contacts with identified amygdalostriatal projection neurons.The present study provides direct anatomical evidence for the physiological observation that GABA exhibits a powerful regulation of the amygdaloid projection neurons in the BL and lends further support to the concept of a corticallike functional organization of the basolateral amygdala.
Galanin hyperinnervates surviving neurons of the human basal nucleus of meynert in dementias of alzheimer's and parkinson's disease: A hypothesis for the role of galanin in accentuating cholinergic dysfunction in dementia
Authors: Chan‐Palay V. 
Published: May 2005

AbstractThis study summarizes the findings from postmortem examination of the brains of 22 control cases without neurological deficit, 12 cases of senile dementia of the Alzheimer type (SDAT), and nine cases of Parkinson's disease (three without signs of intellectual deterioration, four with dementia, and two atypical with dementia nonresponsive to L‐dopa treatment). The aim of this study was to find the similarities and differences in galanin innervation of the cholinergic basal nucleus neurons in these dementing disorders as compared with controls. Immunocytochemistry with antibodies against galanin peptide and against choline acetyltransferase was applied on perfused brain preparations. Galanin peptide is present in the basal nucleus of Meynert neuron networks in the normal human brain: in local circuit neurons, in a number of galanin/cholinergic neurons, and in a feedback circuit (via collaterals) that terminate upon the cholinergic neuronal somata and dendrites. Thus, peptide galanin circuits could function as powerful modulators of the activities of basal nucleus cholinergic neurons, both within the basal forebrain and in their wider projections to the neocortex and amygdala. As galanin has been shown to inhibit cholinergic activity, this galanin network could suppress the activity of cholinergic neurons. In SDAT, there is a primary loss of cholinergic neurons compounded by a secondary reaction of the remaining cholinergic neurons to the terminal degeneration in the cortex. Galanin networks demonstrate an inverse relationship to the cholinergic cell loss. Galanin axons hypertrophy and hyperinnervate the remaining cholinergic neurons. In Parkinson's disease the loss of cholinergic neurons is accentuated by the presence of dementia: the hypertrophy of the galanin axonal networks on cholinergic neurons is dramatic in Parkinson's disease with dementia.These observations throw new light on the neurotransmitter bases for these dementias. Galanin controls cholinergic mechanisms in the basal nucleus of Meynert, and dementia is accompanied by augmentation of galanin innervation onto an already depressed population of cholinergic neurons, thus demonstrating an appreciable amount of plasticity even in aged brain. These findings suggest that the present therapy of cholinergic enhancement as a means to retard intellectual deterioration can by itself have little effect at best, in these dementias. The suppressive effect of galanin peptide has to be reduced or curtailed, perhaps concurrently with the treatment of the cholinergic deficit. It is suggested that the curtailment of galanin activity might be achieved by galanin peptide antagonists or by small organic compounds that react with the galanin receptor and that these may constitute new therapeutic approaches toward dementia.
Neuronal localization of prosomatostatin mRNA in the rat brain with in situ hybridization histochemistry
Authors: Fitzpatrick‐MceElligott Sandra , Card J. Patrick , Lewis Michael E. , Baldino Frank 
Published: May 2005

AbstractIndividual neurons containing prosomatostatin mRNA were identified with in situ hybridization histochemistry. Our results demonstrate a widespread distribution of prosomatostatin mRNA in several regions of the rat central nervous system. Neurons containing this transcript were most abundant in the anterior olfactory nucleus, hypothalamus, hippocampus, and amygdala as well as in all regions of the cerebral cortex. Moreover, the distribution of mRNA‐containing perikarya was coextensive with the location of neurons containing somatostatin‐like immunoreactivity in all areas of the brain examined. Somatostatin neurons varied in their morphology and amount of hybridization signal from region to region. The widespread distribution and regional variations in neuronal morphology and the amount of hybridization signal are consistent with a neurotransmitter and/or a neuromodulator role for somatostatin in addition to its well‐established neuroendocrine role. These results demonstrate that both the peptide and its mRNA are found in perikarya in the same areas and that they are therefore the sites of synthesis for somatostatin.