bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serotoninergic varicosities make synaptic contacts with pleural sensory neurons of Aplysia
Authors: Zhang Z. S. , Fang B. , Marshak D. W. , Byrne J. H. , Cleary L. J. 
Published: January 2005

AbstractSerotonin is a modulatory neurotransmitter that produces many of the cellular changes associated with sensitization of reflexes in Aplysia. These changes have been carefully documented in sensory neurons located in the abdominal ganglion that mediate the gill‐siphon withdrawal reflex and in sensory neurons located in the pleural ganglion that mediate the tail‐siphon withdrawal reflex. Although serotonin appears to be necessary for sensitization, there is no direct evidence that serotoninergic neurons make synaptic contacts with sensory neurons. In this study, the immunoperoxidase technique was used to label serotonin‐immunoreactive neurites surrounding the cell bodies of sensory neurons in the pleural ganglion. Serotonin‐immunoreactive neurites had varicosities whose mean short axis diameter was 1.1 ± 0.6 μm (mean ± S.D.). The shape of the size distribution was skewed toward larger sizes, however, suggesting that there were multiple subpopulations of varicosities. One subpopulation was that of varicosities located at branch points whose average short axis diameter was larger than normal (1.7 ± 0.5 μm). Serotonin‐immunoreactive varicosities were directly apposed to the sensory neurons without intervening glial cells. In most contacts, serotonin‐immunoreactive neurites invaginated into the plasma membranes of the sensory neurons. There were also a few contacts onto spinelike processes, but these were flat rather than invaginated. Serotoninergic neurons whose activity produces changes in the electrophysiological properties of sensory neurons have been identified, but this study provides the first direct evidence for synaptic connections between serotoninergic neurons and sensory neurons in Aplysia.
Differential complementary localization of metabolic enzymes for quinolinic acid in olfactory bulb astrocytes
Authors: Poston Michael R. , Bailey Mary S. , Schwarcz Robert , Shipley Michael T. 
Published: January 2005

AbstractThe cellular localizations of the synthetic [3‐hydroxyanthranilic acid oxygenase (3HAO)] and degradative [quinolinic acid phosphoribosyltransferase (QPRT)] enzymes of the endogenous excitotoxin quinolinic acid were studied in the adult rat main olfactory bulb by immunohistochemical techniques. 3HAO and QPRT were expressed only in astrocytes. The two enzymes were differentially expressed by astrocytes in a complementary pattern: 3HAO staining was strongest at the glomerular–external plexiform layer junction; QPRT staining was strongest at the glomerular–olfactory nerve layer junction. The complementary distributions of these metabolic enzymes suggests that there could be a gradient of quinolinic acid across the glomerular layer of the main olfactory bulb. Such a gradient could function to restrict the ingrowth of new olfactory axons to the glomeruli and/or to stabilize the formation of new synapses.
Acoustic chiasm IV: Eight midbrain decussations of the auditory system in the cat
Authors: Hutson K. A. , Glendenning K. K. , Masterton R. B. 
Published: January 2005

AbstractConventional retrograde and orthograde axonal transport tract‐tracing techniques were used in cats to explore the auditory decussations and commissures in the upper pons and midbrain. In all, 8 decussations differing either in origin or in contralateral termination were found. Three of the 8 decussations (from the dorsal nucleus of the lateral lemniscus to the contralateral dorsal nucleus of the lateral lemniscus, from the dorsal nucleus of the lateral lemniscus to the contralateral inferior colliculus, from the sagulum to the contralateral sagulum) reach their targets via the commissure of Probst. The remaining 5 decussations (from the inferior colliculus to the contralateral inferior colliculus or medial geniculate, from the intermediate nucleus of the lateral lemniscus to the contralateral medial geniculate, from the sagulum to the contralateral inferior colliculus or medial geniculate) reach their targets via the commissure of the inferior colliculus.The results also suggest that the commissure of Probst is not a general avenue for decussating auditory fibers of the lateral lemniscus but is instead a specific avenue only for fibers from the dorsal nucleus of the lateral lemniscus and sagulum. The results also show that, in the cat at least, the dorsal nucleus of the lateral lemniscus does not project beyond the inferior colliculus to either the superior colliculus or medial geniculate‐the cells previously reported as doing so are probably those of the immediate neighbors of the dorsal nucleus, the intermediate nucleus of the lateral lemniscus and sagulum.
Medial terminal nucleus terminals in the nucleus of the optic tract contain GABA: An electron microscopical study with immunocytochemical double labeling of GABA and PHA‐L
Authors: Van Der Togt Chris , Cardozo Bob Nunes , Van Der Want Johannes 
Published: January 2005

AbstractIn this study the medial terminal nucleus (MTN) projection to the nucleus of the optic tract (NOT) was investigated in pigmented rats at the light and electron microscopical levels with a new combination of techniques. MTN terminals were anterogradely labeled with Phaseolus vulgaris‐leucoagglutinin (PHA‐L). Preembedding immunocytochemistry, followed by gold intensification, was used to visualize PHA‐L. Postembedding immunocytochemistry with 15 nm immunogold particles was carried out to demonstrate the inhibitory neurotransmitter gamma‐aminobutyric acid (GABA). Both PHA‐L and GABA labeling can be easily discriminated at the electron microsopical level even when present in the same neuronal profiles.Light microscopically MTN‐NOT fibers proved to have several branches with many varicosities. MTN terminals were found concentrated in terminal fields. Electron microscopically, it was shown that MTN boutons display characteristics resembling F‐type terminals, i.e., terminals with dark mitochondria, pleomorphic vesicles, and symmetrical synapses. All NOT afferents originating from the MTN contained GABA and made multiple contacts exclusively with GABA negative NOT somata and dendrites. These results indicate the existence of a strong and direct inhibitory input onto GABA negative projection neurons in the NOT. This substantiates earlier physiological and morphological reports. It was further demonstrated that the location and organization of MTN terminals in the neuropil differ from that of the retinal input: MTN terminals are largely separated from retinal terminals. MTN terminal fields contain large amounts of GABA positive F terminals in contrast to retinal terminal areas. MTN terminals take part in irregularly shaped agglomerations of terminals, which contain many F terminals and dendritic processes and are surrounded by a glial sheet. Retinal terminals are found grouped together in small circular arrangements contacting a central dendrite.
Substance P immunoreactivity identifies a projection from the cat's superior colliculus to the principal tectorecipient zone of the lateral posterior nucleus
Authors: Hutsler Jeffrey J. , Chalupa Leo M. 
Published: January 2005

AbstractCells in the superficial layers of the superior colliculus innervate multiple visual regions within the pulvinar‐lateral posterior complex of the cat. To characterize these neurons we have examined their immunocytochemical properties in conjunction with their projection patterns. In the present study, we show that a monoclonal antibody for substance P recognizes a morphologically diverse population of neurons, which can be classified as granular, stellate, angular, and horizontal or nonhorizontal fusiform cell types. These neurons are distributed throughout the superficial layers of the colliculus, with a peak density corresponding to sublayer 2 of the stratum griseum superficial. Injections of rhodamine latex microspheres into the pulvinar‐lateral posterior complex demonstrate that a substantial proportion of these collicular cells (at least 35%) project to this region of the posterior thalamus. The overall population of substance P‐containing cells, as well as the immunoreactive projection neurons, is composed of the same proportions of cell classes, with the exception that granular cells were not found to be projection neurons.A distinct wedge of substance P immunoreactivity, consisting of fiber and diffuse extracellular labeling, was discovered in the pulvinar‐lateral posterior complex. This staining was demonstrated to be confined entirely within the medial division of the lateral posterior nucleus, which is considered to be the principal tectorecipient zone of the extrageniculate visual thalamus. Lesions of the superior colliculus largely abolished the substance P immunoreactivity in the ipsilateral tectorecipient zone. These results are consistent with the view that substance P plays a role in the functional organization of the principal tectothalamic pathway of the cat's extrageniculate visual system.
PNS‐CNS transitional zone of the first cranial nerve
Authors: Doucette R. 
Published: January 2005

AbstractThis study examined the ultrastructure of the region of transition where fascicles of olfactory axons leave the peripheral nervous system (PNS) to enter the central nervous system (CNS), the so‐called PNS‐CNS transitional zone. Adult rats were transcardially perfused with a solution of 1% glutaraldehyde and 1% paraformaldehyde, decapitated, and the heads decalcified over a period of several weeks in a solution of 1% glutaraldehyde in 0.1 M tetrasodium ethylenediamine tetraacetic acid; the latter solution was changed daily. It was found that astrocytes did not form the glia limitans at the nerve entry zone, unlike the situation that exists in other cranial and spinal nerves. Rather, the glia limitans in this region of the olfactory bulb was formed by a special type of glial cell, referred to as an ensheathing cell. Ensheathing cells are found only in the nerve fiber layer of the olfactory bulb. They possess a mixture of Schwann cell and astrocytic features and are more likely to be of placodal than of CNS origin. The meningeal coverings of the olfactory nerve rootlets and of the olfactory bulb are also described and the functional implications of the findings discussed.
Nerve growth factor differentially modulates the expression of its receptor within the CNS
Authors: Fusco M. , Polato P. , Vantini G. , Cavicchioli L. , Bentivoglio M. , Leon A. 
Published: January 2005

AbstractThe effect of nerve growth factor on the expression of nerve growth factor receptor in the central nervous system of newborn and adult rats was studied by means of immunohistochemistry with the monoclonal antibody 192‐IgG. Both during development and in adulthood, the intracerebroventricular administration of nerve growth factor elicited a pronounced increase of nerve growth factor receptor‐like immunoreactivity in the cell bodies and neural processes of the basal forebrain cholinergic nuclei, as compared to cytochrome c‐treated rats (controls). A pronounced nerve growth factor‐induced increase of nerve growth factor receptor‐like immunoreactivity was also observed in central regions innervated by trigeminal and spinal ganglia. A moderate to a marked increase of nerve growth factor receptor‐like immunoreactivity was evident in some mesencephalic visual system‐related structures and thalamic nuclei expressing nerve growth factor receptor. In contrast, NGF treatment did not induce appreciable modification of nerve growth factor receptor‐like immunoreactivity in cerebellar, brainstem, and spinal motor structures of newborn rats. In adult nerve growth factor‐treated rats, a decrease of nerve growth factor receptor‐like immunoreactivity was detected in the cerebellum, whereas no re‐expression of nerve growth factor receptor‐like immunoreactivity occurred in the motor structures that had expressed it in the first postnatal week. Finally, nerve growth factor was also found to enhance, in both adult and newborn rats, nerve growth factor receptor‐like immunoreactivity associated with ependymal and subependymal cellular elements of the lateral and third ventricles, as well as with the leptomeninges overlying the superior colliculus and supraoptic area. The present results indicate that endogenous nerve growth factor or nerve growth factor‐like molecules may play a dynamic role in a variety of cell populations of both the developing and mature mammalian central nervous system. We thus propose the nerve growth factor ability to modulate its receptor in vivo as a novel criterion to define nerve growth factor or nerve growth factor‐like molecules, sensitive neuronal, and non‐neuronal cells. Whereas this criterion does not intrinsically possess absolute physiological validity, its pharmacological concomitants might be relevant in view of the proposed therapeutical use of this trophic factor.
Immunocytochemical localization of argininosuccinate synthetase in the rat brain
Authors: Nakamura Hiroyuki , Saheki Takeyori , Ichiki Hitoshi , Nakata Kimihiko , Nakagawa Shiro 
Published: January 2005

AbstractThe neuronal distribution of argininosuccinate synthetase (ASS) was mapped in the rat brain. Argininosuccinate synthetase is one of the enzymes of the arginine metabolic pathway and catabolizes the synthesis of argininosuccinate from aspartate and citrulline. Since arginine is the precursor of nitric oxide, argininosuccinate synthetase may act as part of the nitric oxide producing pathway. Argininosuccinate is also suggested to have a messenger function in the nervous system. Therefore, the localization of ASS is of great interest.Polyclonal antisera against purified rat liver argininosuccinate synthetase revealed a characteristic distribution pattern of argininosuccinate synthetase‐like immunoreactivity: (1) many neurons with strong argininosuccinate synthetase‐like immunoreactivity were observed in the septal area, basal forebrain, anterior medial and premammillary nuclei of the hypothalamus, anterior and midline thalamic nuclei, dorsal endopiriform nucleus of the amygdala, basal nucleus of Meynert, subthalamic nucleus, laterodorsal tegmental nucleus, raphe nuclei, nucleus ambiguus, and the area postrema, (2) neuropile staining was dense in the septal areas, hypothalamus, area postrema, nucleus of the solitary tract, and the laminae I and II of the caudal subnucleus of the spinal trigeminal nucleus and the spinal dorsal horn, (3) relay nuclei of the specific sensory systems such as the dorsal lateral geniculate nucleus and the ventral nuclei of the thalamus were devoid of argininosuccinate synthetase‐like immunoreactivity, (4) no staining was seen in the large white matter structures such as the internal capsule, corpus callosum, and the anterior commissure, and (5) most of the neurons stained were small or medium in size and appeared to be interneurons. The results suggest that argininosuccinate synthetase affects the widely distributed, neuromodulatory system in the brain.
Central projections of auditory‐nerve fibers of differing spontaneous rate. I. Anteroventral cochlear nucleus
Authors: Liberman M. Charles 
Published: January 2005

AbstractAuditory nerve fibers have been subdivided into three functional groups (Liberman, M.C. [1978] J. Acoust. Soc. Am. 63:442–455) differing in acoustic sensitivity and spontaneous discharge rate (SR). Using intracellular injection of horseradish peroxidase, the present study analyzes the projections of these three neuronal subclasses to the various subdivisions of the anteroventral cochlear nucleus (AVON) and to the different cell types found therein. The average number of swellings and number of cells contacted decreased from low‐ to medium‐ to high‐SR groups. However, these differences in terminal elaboration were not evenly distributed throughout the AVCN. The small cell cap was almost exclusively innervated by low‐ and medium‐SR fibers, i.e., those with the highest acoustic thresholds. Within anterior AVCN, spherical‐cell innervation was seen from all SR groups, whereas almost all multipolar cell innervation was from low‐ and medium‐SR fibers. In the posterior AVCN, multipolar‐cell innervation was equally likely from all SR groups, whereas globular cells were preferentially contacted by high‐SR fibers. These SR‐based trends in cochlear nucleus innervation help explain some of the known physiological properties of cell‐types in each subdivision. They also suggest that additional physiological study of the small cell cap may be key in elucidating the functional significance of the low‐SR population.
Characterisation of two new monoclonal antibodies directed against rat microglia
Authors: Gehrmann Jochen , Kreutzberg Georg W. 
Published: January 2005

AbstractWith the aid of cultured rat microglial cells as immunogen, we raised two monoclonal antibodies, designated murine clone (MUC) 101 and 102, which recognised subsets of resident microglial cells in the normal central nervous system and cells of the mononuclear phagocyte system in peripheral organs. These antibodies were characterised by immunoperoxidase immunocytochemistry, immunoelectron microscopy, and immunoblotting.The immunostained cells were identified as microglial cells by double‐immunofluorescence labelling with the B4‐isolectin from Griffonia simplicifolia, an established microglial cell marker. Under normal conditions, both antibodies labeled resident microglia but with different distribution patterns. Under pathological conditions, e.g., after facial nerve transection, they labeled activated, perineuronal microglia in the operated facial nucleus. Immunoelectron microscopy demonstrated a membrane localisation of the antigen recognised by MUC 102.In peripheral organs, MUC 101 and 102 reacted with different cell populations of the mononuclear phagocyte system, particularly in thymus, spleen, and peripheral lymph node. Western blot experiments showed that MUC 101 recognised two proteins of 116 and 95 kD in fractions obtained from operated facial nucleus while MUC 102 reacted with two proteins of 62 and 70 kD molecular weight.These immunocytochemical results (1) confirm the antigenic similarity between microglia and cells of the monocyte–macrophage cell lineage, and (2) indicate that considerable antigen heterogeneity might exist among resident microglia. MUC 101 and 102 could thus become useful for studying the function of microglial cells both under normal and pathological conditions.
Age‐related changes in galanin‐immunoreactive cells of the rat medial septal area
Authors: de Bilbao F. , Jazat F. , Lamour Y. , Senut M. C. 
Published: January 2005

AbstractAge‐related changes in the cholinergic cells have been reported in the rat medial septal area. The neuropeptide galanin is colocalized with acetylcholine in the majority of the medial septal neurons. To assess possible age‐related changes in the galanin‐containing septal cells, we have examined, with immunohistochemical methods, the distribution pattern, density, and morphological features of galanin‐containing cells in the rat medial septal nucleus (MS) and the nucleus of the diagonal band of Broca (DBB) in 1, 3–6, 9–12, 16–18, 24–27, and 28–30 month‐old rats. A morphometric computerized analysis was also performed. In addition, the intensity of the immunolabelling was measured by densitometry. Galanin‐like immunoreactivity (galanin‐LI) was present in both the MS and the DBB. Our results clearly indicate a progressive age‐related decrease in the number of galanin‐positive cells throughout the MS‐DBB complex. Our quantitative study revealed a significant loss of galanin‐positive cells in the MS‐DBB complex of 16–18 (50.4%), 24–27 (52.3%), and 28–30 (52.4%) month‐old rats compared to 3–6 month‐old animals. A non‐significant reduction (28.6%) in galanin‐LI cell number was observed in 3–6 month‐old rats compared to 1 month‐old animals. The morphometric analysis demonstrated a significant reduction (18%) in the surface of galanin‐positive cells remaining in the 28–30 month‐old group. Furthermore, a significant decrease in the immunolabelling intensity was consistently observed in animals of 16 month‐old and older. To determine whether changes in galanin‐positive cells were associated with cholinergic changes, the number of cells stained for acetylcholinesterase.(AChE) was estimated in 3–6, 9–12, 16–18, and 24–27 month‐old rats. There was a 43% decrease in the number of AChE‐positive cells and a 71% loss of galanin‐positive cells in 24–27 month‐old rats compared to 3–6 month‐old. The galanin‐cell loss in, the medial septal area was therefore associated with a parallel, although smaller, cholinergic septal cell loss.
Different populations of parvalbumin‐ and calbindin‐D28k‐immunoreactive neurons contain GABA and accumulate 3H‐D‐aspartate in the dorsal horn of the rat spinal cord
Authors: Antal Miklos , Polgár E. , Chalmers J. , Minson J. B. , Llewellyn‐Smith I. , Heizmann C. W. , Somogyi P. 
Published: January 2005

AbstractThe colocalization of parvalbumin (PV), calbindin‐D28k (CaBP), GABA immunoreactivities, and the ability to accumulate 3H‐D‐aspartate selectively were investigated in neurons of laminae I‐IV of the dorsal horn of the rat spinal cord. Following injection of 3H‐D‐aspartate into the basal dorsal horn (laminae IV‐VI), perikarya selectively accumulating 3H‐D‐aspartate were detected in araldite embedded semithin sections by autoradiography, and consecutive semithin sections were treated to reveal PV, CaBP and GABA by postembedding immunocytochemistry. Perikarya accumulating 3H‐D‐aspartate were found exclusively in laminae I–III, and no labelled somata were found in deeper layers or in the intermediolateral column although the labelled amino acid clearly spread to these regions. More than half of the labelled cells were localized in lamina II. In this layer, 16.4% of 3H‐D‐aspartate‐labelled perikarya were also stained for CaBP. In contrast to CaBP, PV or GABA was never detected in neurons accumulating 3H‐D‐aspartate. A high proportion of PV‐immunoreactive perikarya were also stained for GABA in laminae II and III (70.0% and 61.2% respectively). However, the majority of CaBP‐immunoreactive perikarya were GABA‐negative. GABA‐immunoreactivity was found in less than 2% of the total population of cells stained for CaBP in laminae I–IV. A significant proportion of the GABA‐negative but PV‐immunoreactive neurons also showed CaBP‐immunoreactivity in laminae IL and IV. These results show that out of the two calcium‐binding proteins, CaBP is a characteristic protein of a small subpopulation of neurons using excitatory amino acids and PV is a characteristic protein of a subpopulation of neurons utilizing GABA as a transmitter. However, both proteins are present in additional subgroups of neurons, and neuronal populations using inhibitory or excitatory amino acid transmitters are heterogeneous with regard to their content of calcium‐binding proteins in the dorsal horn of the rat spinal cord.