bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH‐d) cells and fibers in the monkey amygdaloid complex
Authors: Pitkänen Asla , Amaral David G. 
Published: January 2005

AbstractThe NADPH‐d histochemical method stains a selective population of neurons in the central nervous system. Although the functional significance of the enzyme in these cells is unknown, it has nonetheless proved to be a useful marker. In the present study we describe the distribution of NADPH‐d‐positive cells and fibers in the amygdaloid complex of the Macaca fascicularis monkey.NADPH‐d‐positive neurons were distributed throughout the amygdaloid complex. Based on the intensity of the reaction product, three different types of NADPH‐d positive cell were described: type 1 cells, the most intensely stained, varied in morphology and were most commonly found in the accessory basal, basal, and lateral nuclei and in the nucleus of the lateral olfactory tract; type 2 cells, the most common NADPH‐d‐positive cells, were more lightly stained, were generally stellate in shape, and were found in the lateral, basal, and accessory basal nuclei; type 3 cells were very lightly stained, oval or round in shape, and mostly found in the medial, anterior cortical, and paralaminar nuclei.NADPH‐d staining was also associated with axonal fiber plexuses in various regions of the amygdala. The highest densities of stained fibers were found in the lateral nucleus, the parvicellular portion of the accessory basal nucleus, and the anterior amygdaloid area. The lowest densities of NADPH‐d‐positive fiber staining were found in the amygdalohippocampal area, in the lateral part of the central nucleus, and in the intercalated nuclei. In addition to the neuronal and fiber staining, a diffuse, blue neuropil staining was also observed, most commonly in the anterior cortical nucleus, the medial nucleus, the intercalated nuclei, and especially in the amygdalohippocampal area. The distribution of NADPH‐d staining often respected nuclear boundaries within the amygdala and was particularly helpful in clarifying the borders of the amygdalohippocampal area.
GABA‐synthesizing neurons in the medulla: Their relationship to serotonin‐containing and spinally projecting neurons in the rat
Authors: Jones Barbara E. , Holmes Colin J. , Rodriguez‐Veiga Elisia , Mainville Lynda 
Published: January 2005

AbstractGABA‐synthesizing neurons were identified in the medulla of the rat by peroxidase‐antiperoxidase (PAP) immunohistochemistry for glutamic acid decarboxylase (GAD). Using diaminobenzidine (DAB) either alone or intensified with silver, a relatively large number of GAD‐immunoreactive neurons were evident within the reticular formation, raphe nuclei and vestibular nuclei. In all these areas, profuse GAD‐immunoreactive varicosities appeared to contact the soma and dendrites of both non‐GABA and GABA neurons. These observations suggest that GABA neurons may act as interneurons or local projection neurons within the medulla and accordingly exert a potent inhibitory and/or disinhibitory control on bulbar projection neurons.Within the ventral reticular formation (pars alpha and ventralis of the gigantocellular reticular field) and raphe magnus, large numbers of prominent GAD‐immunoreactive neurons resembled in size and morphology and overlapped in distribution the serotonin‐immunoreactive neurons of the same regions. However, by sequential double immunostaining utilizing DAB as a chromogen for serotonin (5‐HT) and benzidine dihydrochloride (BDHC) for GAD, it was found that GAD‐containing neurons were distinct from 5‐HT‐containing neurons.Following injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA‐HRP) into the upper cervical spinal cord and combined processing for WGA‐HRP (using tetramethylbenzidine [TMB] with cobalt) and immunohistochemistry (with DAB), a contingent of spinally projecting neurons were found to contain GAD. The GAD‐immunoreactive reticulo‐and raphe‐spinal neurons were most frequent within the pars alpha and ventralis of the gigantocellular reticular fields and the raphe magnus, where they were approximately equal in number to the coexistent, but distinct 5‐HT spinally projecting neurons. GABA neurons of the medulla may thus contribute directly to the bulbar inhibitory influence upon spinal sensory and motor systems.
A possible mechanism of mechanoreception in Ruffini endings in the periodontal ligament of hamster incisors
Authors: Kannari Koichi , Sato Osamu , Maeda Takeyasu , Iwanaga Toshihiko , Fujita Tsuneo 
Published: January 2005

AbstractThe topographical relationship between Ruffini endings and the surrounding collagen fibers in the periodontal ligament of hamster incisors was investigated by means of both immunohistochemistry for neurofilament protein (NFP) and electron microscopy. Periodontal Ruffini endings, a type of stretch receptor, were present exclusively in the alveolar half of the periodontal ligament. Their axon terminals were densely and regularly associated with transverse collagen fibers, possibly forming a mechanoreceptive complex. Since blood sinuses with frequent anastomoses extended throughout the alveolus‐related part, the densely innervated collagen bundles were separated from each other by the vascular spaces. Electron microscopic observation of specimens stained with tannic acid revealed a linkage between the axon terminals of the Ruffini endings and the surrounding collagen filaments. The axon terminals were enveloped by multiple layers of the basal lamina, which were penetrated by collagen filaments. The irregularly arranged collagen filaments were sandwiched between electron‐dense laminae of the multilayered basal lamina. The possible mechanism of mechanoreception by the periodontal Ruffini endings is discussed on the basis of the immunohistochemical and ultrastructural findings.
Type I corticosteroid receptor‐like immunoreactivity in the rat CNS: Distribution and regulation by corticosteroids
Authors: Ahima Rexford , Krozowski Zygmunt , Harlan Richard E. 
Published: January 2005

AbstractPrevious maps of Type I corticosteroid receptor binding in the rat central nervous system (CNS) revealed a restricted distribution of the receptor in limbic regions, hypothalamus, and circumventricular organs. More recent studies have shown a more widespread expression of the receptor, with high levels of Type I receptor mRNA in limbic, motor, and sensory systems. We have used two antisera against peptide sequences derived from the cDNA of the human Type I corticosteroid receptor to map the regional distribution and corticosteroid regulation of the intracellular location of Type I corticosteroid receptor‐like immunoreactivity (Type I‐ir) in the rat CNS.Neurons showing Type I‐ir were observed at all levels of the CNS. Highest densities of immunoreactive neurons were observed in limbic regions, isocortex, and some thalamic nuclei. Motor, sensory, and visceral systems often showed moderate densities of immunoreactive neurons. Type I‐ir glia were observed in some fiber systems, e.g., corpus callosum, medial lemniscus, cerebral peduncles, spinal trigeminal tract, and funiculi of the spinal cord. In the majority of neurons and in glia, Type I‐ir showed a diffusely nuclear and cytoplasmic location, Long‐term adrenalectomy reduced immunoreactivity in most neurons and glia. Neuronal Type I‐ir was localized mainly in the cytoplasm after long‐term adrenalectomy. Nuclear immunoreactivity was retained in some neurons in the globus pallidus, motor trigeminal nucleus, and laminae 8 and 9 of the spinal cord. Acute treatment with corticosterone or aldosterone restored neuronal and glial Type I‐ir to densities below that seen in intact rats.
Hypothalamic paraventricular nucleus: A quantitative analysis of cytoarchitectonic subdivisions in the rat
Authors: Kiss Jozsef Zoltan , Martos Janos , Palkovits Miklos 
Published: January 2005

AbstractThe boundaries of subnuclei of the hypothalamic paraventricular nucleus (PVN) were outlined on the basis of a step by step computer‐assisted image analysis of coronal, serial sections of the hypothalamus in rats. The cell size‐frequency histogram, cell packing density, and the cell number were determined for each PVN subdivision. Three principal cell types were distinguished: small, short diameter (d) = 6–10 μm; medium‐sized, d = 10–13 μm; and large, d = 13–19 μm. None of these cell types occur exclusively in any PVN subdivision. According to the predominant cell type, the PVN can be divided into magnocellular, mediocellular and parvicellular subnuclei. Large cells appear to form one subdivision in which the cell packing density is relatively stable. Although the cell sizes showed a relatively large variation, no definitive subgroups (parts) could be distinguished. On the basis of cell packing density, the parvicellular and mediocellular subnuclei can be further divided. The mediocellular cell group can be divided into a dorsal and a posterior subdivision. The parvicellular zone is subdivided into a periventricular and a large medial subdivision. Based on inhomogeneities in cell packing density, the medial subdivision can be further divided into anterior, dorso‐lateral, ventro‐medial and caudal parts.The estimated total cell number in the PVN (in both sides of the brain) is about 21,500. On average, 19% of this population, i.e., 4,200 neurons, was calculated in the magnocellular (neurosecretory) division. Out of this, only 66%, about 2,700 cells, falls into the category of large cells. There are approximately 5,700 neurons in the posterior and dorsal mediocellular, and about 11,600 in the periventricular and medial parvicellular subdivisions.
A PHA‐L analysis of ascending projections of the dorsal raphe nucleus in the rat
Authors: Vertes Robert P. 
Published: January 2005

AbstractAscending projections from the dorsal raphe nucleus (DR) were examined in the rat by using the anterograde anatomical tracer, Phaseolus vulgaris leucoagglutinin (PHA‐L). The majority of labeled fibers from the DR ascended through the forebrain within the medial forebrain bundle. DR fibers were found to terminate heavily in several subcortical as well as cortical sites.The following subcortical nuclei receive dense projections from the DR: ventral regions of the midbrain central gray including the ‘supraoculomotor central gray’ region, the ventral tegmental area, the substantia nigra‐pars compacta, midline and intralaminar nuclei of the thalamus including the posterior paraventricular, the parafascicular, reuniens, rhomboid, intermediodorsal/mediodorsal, and central medial thalamic nuclei, the central, lateral and basolateral nuclei of the amygdala, posteromedial regions of the striatum, the bed nucleus of the stria terminalis, the lateral septal nucleus, the lateral preoptic area, the substantia innominata, the magnocellular preoptic nucleus, the endopiriform nucleus, and the ventral pallidum. The following subcortical nuclei receive moderately dense projections from the DR: the median raphe nucleus, the midbrain reticular formation, the cuneiform/pedunculopontine tegmental area, the retrorubral nucleus, the supramammillary nucleus, the lateral hypothalamus, the paracentral and central lateral intralaminar nuclei of the thalamus, the globus pallidus, the medial preoptic area, the vertical and horizontal limbs of the diagonal band nuclei, the claustrum, the nucleus accumbens, and the olfactory tubercle.The piriform, insular and frontal cortices receive dense projections from the DR; the occipital, entorhinal, perirhinal, frontal orbital, anterior cingulate, and infralimbic cortices, as well as the hippocampal formation, receive moderately dense projections from the DR.Some notable differences were observed in projections from the caudal DR and the rostral DR. For example, the hippocampal formation receives moderately dense projections from the caudal DR and essentially none from the rostral DR. On the other hand, virtually all neocortical regions receive significantly denser projections from the rostral than from the caudal DR.The present results demonstrate that dorsal raphe fibers project significantly throughout widespread regions of the midbrain and forebrain.
GABAergic interneurons containing calbindin D28K or somatostatin are major targets of GABAergic basal forebrain afferents in the rat neocortex
Authors: Freund Tamás F. , Gulyás A. I. 
Published: January 2005

AbstractThe arborization pattern and postsynaptic targets of the GABAergic component of the basal forebrain projection to neo‐ and mesocortical areas have been studied by the combination of anterograde tracing and pre‐ and postembedding immunocytochemistry. Phaseolus vulgaris leucoagglutinin (PHAL) was iontophoretically delivered into the region of the diagonal band of Broca, with some spread of the tracer into the substantia innominata and ventral pallidum. A large number of anterogradely labelled varicose fibres were visualized in the cingulate and retrosplenial cortices, and a relatively sparse innervation was observed in frontal and occipital cortical areas. Most of the labelled axons were studded with large en passant varicosities (Type 1), whereas the others (Type 2) had smaller boutons often of the drumstick type. Type 1 axons were distributed in all layers of the mesocortex with slightly lower frequency in layers 1 and 4. In the neocortex, layer 4, and to a smaller extent upper layer 5 and layer 6 contained the largest number of labelled fibres, whereas only a few fibres were seen in the supragranular layers. Characteristic type 2 axons were very sparse but could be found in all layers.Most if not all boutons of PHAL‐labelled type 1 axons were shown to be GABA‐immunoreactive by immunogold staining for GABA, Altogether 73 boutons were serially sectioned and found to make symmetrical synaptic contacts mostly with dendritic shafts (66, 90% of total targets), cell bodies (6, 8.2% of total), and with one spine. All postsynaptic cell bodies, and the majority of the dendritic shafts (44, 60.3% of total targets) were immunoreactive for GABA. Thus at least 68.5% of the total targets were GABA‐positive, but the majority of the dendrites not characterized immunocytochemically for technical reasons (15.1%) also showed the fine structural characteristics of nonpyramidal neurons.The target interneurons included some of the somatostatin‐ and calbindin‐containing subpopulations, and a small number of parvalbumin‐containing neurons, as shown by double immunostaining for PHAL and calcium‐binding proteins or neuropeptides.We suggest that the innervation of inhibitory interneurons having extensive local axon arborizations may be a mechanism by which basal forebrain neurons–most notably those containing GABA–have a powerful global effect on the majority of principal cells in the entire cortical mantle.
Central projections of auditory nerve fibers in the barn owl
Authors: Carr C. E. , Boudreau R. E. 
Published: January 2005

AbstractThe central projections of the auditory nerve were examined in the barn owl. Each auditory nerve fiber enters the brain and divides to terminate in both the cochlear nucleus angularis and the cochlear nucleus magnocellularis. This division parallels a functional division into intensity and time coding in the auditory system. The lateral branch of the auditory nerve innervates the nucleus angularis and gives rise to a major and a minor terminal field. The terminals range in size and shape from small boutons to large irregular boutons with thorn‐like appendages. The medial branch of the auditory nerve conveys phase information to the cells of the nucleus magnocellularis via large axosomatic endings or end bulbs of Held. Each medial branch divides to form 3–6 end bulbs along the rostrocaudal orientation of a single tonotopic band, and each magnocellular neuron receives 1–4 end bulbs. The end bulb envelops the postsynaptic cell body and forms large numbers of synapses. The auditory nerve profiles contain round clear vesicles and form punctate asymmetric synapses on both somatic spines and the cell body.
Synaptic inputs to physiologically identified retinal X‐cells in the cat
Authors: Weber A. J. , McCall M. A. , Stanford L. R. 
Published: January 2005

AbstractThe cat retina contains a number of different classes of ganglion cells, each of which has a unique set of receptive field properties. The mechanisms that underlie the functional differences among classes, however, are not well understood. All of the afferent input to retinal ganglion cells are from bipolar and amacrine cell terminals in the inner plexiform layer, suggesting that the physiological differences among cat retinal ganglion cells might be due to differences in the proportion of input that they receive from these cell types.In this study, we have combined in vivo intracellular recording and labeling with subsequent ultrastructural analysis to determine directly the patterns of synaptic input to physiologically identified X‐cells in the cat retina. Our primary aim in these analyses was to determine whether retinal X‐cells receive a characteristic pattern of bipolar and amacrine cell input, and further, whether the functional properties of this cell type can be related to identifiable patterns of synaptic input in the inner plexiform layer. We reconstructed the entire dendritic arbor of an OFF‐center X‐cell and greater than 75% of the dendritic tree of an ON‐center X‐cell and found that (1) both ON‐ and OFF‐center X‐cells are contacted with approximately the same frequency by bipolar and amacrine cell terminals, (2) each of these input types is distributed widely over their dendritic fields, and (3) there is no significant difference in the pattern of distribution of bipolar and amacrine cell synapses onto the dendrites of either cell type. Comparisons of the inputs to the ON‐ and the OFF‐center cell, however, did reveal differences in the complexity of the synaptic arrangements found in association with the two neurons; a number of complex synaptic arrangements, including serial amacrine cell synapses, were found exclusively in association with the dendrites of the OFF‐center X‐cell.Most models of retinal X‐cell receptive fields, because their visual responses share a number of features with those of bipolar cells, have attributed X‐cell receptive field properties to their bipolar cell inputs. The data presented here, the first obtained from analyzing the inputs to the entire dendritic arbors of retinal X‐cells, demonstrate that these retinal ganglion cells receive nearly one‐half of their input from amacrine cells. These results clearly indicate that further data concerning the functional consequences of amacrine cell input are needed to understand more fully visual processing in the X‐cell pathway.
The distribution of neuropeptides in the dorsomedial telencephalon of the pigeon (Columba livia): A basis for regional subdivisions
Authors: Erichsen Jonathan T. , Bingman Verner P. , Krebs John R. 
Published: January 2005

AbstractThe distribution of six neuropeptides [substance P (SP), leucine (leu5‐) enkephalin (LANK), vasoactive intestinal polypeptide (VIP), cholecystokinin (CCK), neuropeptide Y (NPY), and somatostatin (SS)] in the dorsormedial telencephalon (hippocampal region) of the pigeon was studied by immunohistochemistry.All six peptides were found in fibers passing through the septo‐hippocampal junction and along the medial wall of the hippocampal region. NPY‐, SS‐, and VIP‐like staining of fibers was seen in the hippocampal commissure. NPY and SS had similar distributions within the hippocampal region, both being most conspicuous in cell bodies, terminals, and fibers of the medial hippocampal region. VIP‐positive cells were found in an area dorsal to the SS/NPY cell region. CCK‐like immunoreactivity was found in terminal baskets surrounding large cells of a v‐shaped structure in the ventromedial hippocampal region. SP‐ and LENK‐like immunoreactivity was found in neuropils in a lateral‐dorsal region, the two substances showing similar distributions. This region is thought to lie lateral to the limit of the hippocampal region.Parallels with the distribution of immunoreactivity in the mammalian hippocampus are used to suggest possible equivalent subdivisions of the avian and mammalian hippocampal regions.
Selective localization of polyribosomes beneath developing synapses: A quantitative analysis of the relationships between polyribosomes and developing synapses in the hippocampus and dentate gyrus
Authors: Steward Oswald , Falk Paula M. 
Published: January 2005

AbstractPrevious studies have revealed that polyribosomes are selectively localized beneath post‐synaptic sites on central nervous system (CNS) neurons, and are particularly prominent during periods of synapse growth. The present study evaluates whether polyribosomes are most prominent at a consistent time in the developmental history of the synapse, or instead at a consistent time in the life of the organism regardless of the state of synaptic maturation (suggesting a globally acting factor). We compare the time course of synaptogenesis and the association between polyribosomes and developing synapses in three regions that develop at different rates: the external and internal blades of the dentate gyrus, and the CA1 region of the hippocampus proper. Each region was examined electron microscopically at 1, 4, 7, 10, 15, 20, 28 and over 120 days of age, evaluating: (1) synapse density (the number of synaptic profiles/ area of neuropil), (2) the width of the neuropil layers, (3) the proportion of synapses with underlying polyribosomes, and (4) the number of polyribosome‐containing synapses/area of neuropil.As anticipated on the basis of the differences in cytogenesis, the time course of synaptogenesis was different in the three regions. In the external blade of the dentate gyrus, synapse density increased in a nearly linear fashion between birth and 15 days of age, and then continued to increase at a somewhat slower rate until 28 days of age. Synapse development in the internal blade was delayed by several days in comparison to the external blade. In CA1, synapse density increased slowly between 1 and 7 days, and then at a rapid rate between 7 and 28 days of age. In all three regions, the proportion of synapses with underlying polyribosomes was highest between 1 and 7 days of age, and then decreased as synapse density increased. However, the peak in the number of polyribosome‐containing synapses/unit area of neuropil occurred at different times in the three regions (4–7 days of age in the external blade of the dentate gyrus and in CA1, and 20 days of age in the internal blade). In addition to further defining the relationship between polyribosomes and developing synapses, the present study provides a data base on the time course of synapse development in the hippocampus and dentate gyrus, which will be useful for comparisons with other measures.