bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glutamate decarboxylase‐immunoreactive structures in the rat neostriatum: A correlated light and electron microscopic study including a combination of Golgi impregnation with immunocytochemistry
Authors: Bolam J. P. , Powell J. F. , Wu J.‐Y. , Smith A. D. 
Published: January 2005

AbstractAn antibody to glutamate decarboxylase has been used in a light and electron microscopic study of the neostriatum of rats that had received intracerebral injections of colchicine. In the light microscope, neuronal perikarya and small punctate structures that displayed immunoreactivity were found. The perikarya could be divided into two classes based on their sizes: small‐to‐medium‐sized and large. Proximal dendrites, axon initial segments, and axon collaterals were occasionally stained. When the nuclei of the neurons were visible, they possessed indentations. The immunoreactive punctate structures were spread evenly throughout the neostriatum but occasionally were associated with immunoreactive and nonimmunoreactive perikarya.When the same sections were examined in the electron microscope, the small‐to‐medium‐sized immunoreactive perikarya were found to be similar in morphology and synaptic input to a class of Golgi‐impregnated neuron that has been previously shown to accumulate locally administered, radiolabelled γ‐aminobutyric acid. Neurons with the ultrastructural characteristics of typical striatonigral neurons did not display immunoreactivity. As neurons in this pathway probably contain γ‐aminobutyric acid, it is possible that our procedure or our antibody does not stain all γ‐aminobutyric‐acid‐containing structures in the neostriatum.A total of 404 immunoreactive punctate structures were examined by correlated light and electron microscopy or by electron microscopy alone. They were identified as immunoreactive axonal boutons and each of them, when examined in serial sections, displayed typical synaptic specialisations. Membrane specialisations were always of the symmetrical type. At least five distinct targets of the immunoreactive terminals were identified: (1) neurons that were themselves immunoreactive for glutamate decarboxylase; the immunoreactive terminals made synaptic contact with all parts of the neurons examined, i.e., perikarya, proximal dendrites, and axon initial segments. (2) Neurons identified by Golgi impregnation of the same sections as medium‐sized and densely spiny; the immunoreactive terminals made contact predominantly with the perikarya and dendritic shafts. (3) Large neurons found only in the ventral caudate‐putamen, whose somata and dendrites were ensheathed in immunoreactive terminals. (4) Medium‐sized nonimmunoreactive perikarya that possessed nuclear indentations. (5) Large nonimmunoreactive perikarya that had the typical structural features of striatal cholinergic neurons.It is concluded that there is a diverse innervation of many types of striatal neuron by synaptic terminals that possess the ability to synthesize γ‐aminobutyric acid and that these terminals probably arise from neurons within the neostriatum.
Patterns of muscarinic cholinergic binding in the striatum and their relation to dopamine islands and striosomes
Authors: Nastuk Mary A. , Graybiel Ann M. 
Published: January 2005

AbstractThe distribution of muscarinic cholinergic binding sites in the striatum was studied in relation to the locations of other neurochemical markers in the developing rat, cat, ferret, and human. In addition, patterns of striatal muscarinic binding were studied in the adult cat. Receptor binding autoradiography was carried out with tritiated propylbenzilylcholine mustard ([3H]‐PrBCM), an irreversible muscarinic antagonist, and subsequent serial section analyses involved comparisons among patterns of muscarinic binding, catecholamine histofluorescence, acetylcholinesterase (AChE) staining, Nissl staining, and cell labeling with [3H]‐thymidine.Muscarinic binding in the immature striatum was characterized by local patchiness as well as regional density gradients in all species, with the most complex patterns appearing in the human. Patches of dense muscarinic binding were shown to lie in register with fluorescent dopamine islands (rat, cat, ferret), with AChE‐positive patches (all species), and with clusters of neurons pulse‐labeled by exposure to [3H]‐thymidine on embryonic day 27 (ferret). At the developmental stages examined, the [3H]‐PrBCM‐positive patches were roughly aligned with regions of weak Nissl staining (cat, human).Striatal [3H]‐PrBCM binding in the adult cat was dense, and though it usually appeared nearly homogeneous, in some sections patches of elevated binding were present. These had as counterparts, in neighboring sections, AChE‐poor striosomes. We conclude that during development muscarinic cholinergic function is compartmentalized in the striatum in association with dopamine‐containing afferents, and that this compartmentalization may persist to some degree in the adult.
A comparative analysis of glial and neuronal markers in the retina of fish: Variable character of horizontal cells
Authors: Linser P. J. , Smith K. , Angelides K. 
Published: January 2005

AbstractThe immunohistochemical localizations of the enzymes glutamine synthetase, carbonic anhydrase‐C, and the intermediate filament protein GFA were examined for potential neuroglial specificity in the retinas of several types offish. Both glutamine synthetase and carbonic anhydrase‐C appear to be characteristic markers for retinal Müller cells. However, the horizontal neurons of most fish examined also possess high levels of carbonic anhydrase. Furthermore, GFA, the characteristic marker for fibrous astroglia in higher vertebrates, was found specifically localized in the horizontal neurons of several teleost fish. The identity of the GFA antigens was qualified by immunochemical as well as cytological examinations. Furthermore, specific antisera to other intermediate filament proteins, including neurofilaments, validated and contrasted with the observations made with antisera to GFA. The presence of GFA in horizontal neurons of fish is widespread but not typical of all fish. These observations indicate an evolutionary constancy of retinal Müller glial cells. However, these results again focus attention on whether horizontal cells are truly neurons or rather represent an intermediate cell type that may prove useful in studying the evolution, ontogeny, and functional significance of the neuronal‐glial phenotypic dichotomy.
A study of postmortem autolysis in the human organ of corti
Authors: Nadol Joseph B. , Burgess Barbara 
Published: January 2005

AbstractForty‐six human temporal bones from 24 individuals were removed at autopsy and prepared for electron microscopy. The adequacy of histologic preservation was evaluated by light and electron microscopy. Characteristic autolytic changes included vacuolization of afferent neurons and neural poles of inner and outer hair cells, lysis of limiting membranes of hair and supporting cells, swelling of endoplasmic reticulum, and dissolution of mitochondrial cristae.The rate of autolysis varied significantly within cellular components of the inner ear. The neural poles of hair cells demonstrated more rapid autolysis than apical poles and nerve terminals showed more autolysis than myelinated nerve fibers. Postmortem time and the cause of death affected the adequacy of histologic preservation. Fixation in patients dying of pneumonia, hypoxia, head injury, or malignancy tended to be poor, whereas the fixation achieved in patients dying of cardiac disease with postmortem time of under 140 minutes was generally good.
The midbrain periaqueductal gray in the rat. I. Nuclear volume, cell number, density, orientation, and regional subdivisions
Authors: Beitz Alvin J. 
Published: January 2005

AbstractThe midbrain periaqueductal gray is a functionally heterogeneous region which plays an important role in pain modulation. Despite the heterogeneity considerable controversy exists regarding the presence or absence of morphological subdivisions within the region. The present study was designed to evaluate the possibility of morphological subdivisions within the rat periaqueductal gray by using a statistical cluster analysis system. In addition both qualitative and quantitative data concerning neuronal size, shape, and density were obtained. On the basis of measurements of over 12,000 neurons in two planes of section, the mean neuronal length of cell bodies in this region was 14.82 μm and the mean neuronal area was 95.59 μm2. The mean neuronal density was found to be 16,284 cells per mm3. Neuronal density decreased from rostral to caudal in the periaqueductal gray. The data obtained from cluster maps suggest the presence of four subdivisions within this midbrain region. The medial subdivision contains the smallest neurons and exhibits the lowest cell density. The dorsolateral and ventrolateral divisions contain the largest neurons while the dorsal division displays the highest packing density. These results are discussed in light of recent receptor binding and immunohistochemical studies of this region.
Cholecystokinin‐immunoreactive cells form symmetrical synaptic contacts with pyramidal and nonpyramidal neurons in the hippocampus
Authors: Nunzi M. G. , Gorio A. , Milan F. , Freund T. F. , Somogyi P. , Smith A. D. 
Published: January 2005

AbstractThe ultrastructural features and synaptic relationships of cholecystokinin (CCK) Immunoreactive cells of rat and cat hippocampus were studied using the unlabeled antibody immunoperoxidase technique and correlated light and electron microscopy. CCK‐positive perikarya of variable shape and size were distributed in all layers and were particularly concentrated in stratum pyramidale and radiatum: the CCK‐immunoreactive neurons were nonpyramidal in shape and the three most common types had the morphological features of tufted, bipolar, and multipolar cells.Electron microscopic examination revealed that all the CCK‐positive boutons established symmetrical (Gray's type II) synaptic contacts with perikarya and dendrites of pyramidal and nonpyramidal neurons. The origin of some of the boutons was established by tracing fine collaterals that arose from the main axon of two CCK‐immunostained cells and terminated in the stratum pyramidale; these collaterals were then examined in the electron microscope. The axon of one such neuron exhibited a course parallel to the pyramidal layer and formed pericellular nets of synaptic boutons upon the perikarya of pyramidal neurons. This pattern of axonal arborization is very similar to that of some of the basket cells, previously suggested to be the anatomical correlate for pyramidal cell inhibition. Typical dendrites of pyramidal cells also received symmetrical synaptic contacts from CCK‐immunoreactive boutons, and some of these boutons could be shown to originate from a local neuron in stratum radiatum. Many CCK‐immunoreactive cells received CCK‐labeled boutons upon their soma and dendritic shafts. Synaptic relationship, established by multiple Men passant boutons, was observed between CCK‐positive interneurons of the stratum lacunosum‐moleculare and radiatum. The soma and dendrites of the CCK‐immunostained neurons also received symmetrical and asymmetrical synapses from nonimmuno‐reactive boutons.These results indicate that the CCK‐immunoreactive neurons participate in complex local synaptic interactions in the hippocampus.
Postnatal changes in the distribution of acetylcholinesterase in kitten striate cortex
Authors: Bear Mark F. , Carnes Kenneth M. , Ebner Ford F. 
Published: January 2005

AbstractWe have traced the postnatal development of axons and cells in kitten striate cortex that contain acetylcholinesterase (AChE) by using a modification of Koelle's histochemical method.The maturation of AChE‐positive axons was not found to be fully complete until at least 3 months of age, and was characterized by several distinct developmental trends. AChE‐positive fibers in layers IVc–VI proliferate rapidly after birth until, by 4 weeks postnatal, they appear to exceed the adult density. They remain at this level as late as 8 weeks and then decrease to the adult density by 13 weeks. In contrast, the AChE‐positive fibers in layer I do not show a substantial increase in density until 6 weeks of age and the adult level is not achieved before 3 months postnatal. Finally, the density of AChE‐positive fibers in layers II and III appears to increase gradually from birth until the mature pattern is reached at about 6 weeks.AChE could also be localized histochemically to cell bodies whose position and appearance depended on postnatal age. Stained cells first appeared in the white matter subjacent to layer VI shortly after birth. By 2 weeks of age, most cells in layer VI were also AChE positive. The staining of these cells gradually disappears over the next 2 months until, at 3 months of age, there are no AChE‐positive cells in cat striate cortex. However, a subpopulation of stained neurons appears in layer V by 1 year of age that persists throughout adulthood.The possible contributions of acetylcholine and AChE to the postnatal development of kitten striate cortex are discussed.
Projections from the anterior ventral cochlear nucleus to the central nucleus of the inferior colliculus in young and aging C57BL/6 mice
Authors: Willott James F. , Pankow David , Hunter Kelly Paris , Kordyban Mary 
Published: January 2005

AbstractProjections from the anterior ventral cochlear nucleus (AVCN) to the central nucleus of the inferior colliculus (ICC) were studied in young and aging C57BL/6 mice. The latter animals demonstrate progressive loss of hearing. Wheat germ agglutinin‐horseradish peroxidase (WGA‐HRP) was injected into the inferior colliculus and retrograde transport to the AVCN was evaluated. No age‐related differences were found in the area of AVCN sections, quality or labelling, number of labelled neurons adjusted for injection size, or topographic organization of projections. Thus, despite progressing loss of auditory sensitivity, chronic profound hearing loss (oldest animals), and aging, projections from AVCN to ICC remain stable.
Anatomical identification of neurons in selected brain regions associated with maternal behavior deficits induced by knife cuts of the lateral hypothalamus in rats
Authors: Numan Michael , Morrell Joan I. , Pfaff Donald W. 
Published: January 2005

AbstractThe present experiment identified neurons associated with maternal behavior deficits induced by damage to the lateral hypothalamus (LH) in rats. Fully maternal lactating rats received bilateral coronal knife cuts through either the dorsal or ventral LH at the level of the ventromedial nucleus. The blade of the wire knife used to make the cuts was coated with horseradish peroxidase (HRP). The maternal behavior of all females was studied for 4 days postoperatively and then the brains were processed for the localization of neurons retrogradely filled with HRP. The analysis focused on those brain regions thought to be important for maternal behavior.The dorsal LH cuts severely disrupted maternal behavior while the ventral LH cuts did not. The ventral cuts labeled more medial preoptic area (MPOA) and septal‐diagonal band neurons with HRP than did the dorsal cuts. The dorsal LH cuts labeled more neurons with HRP in the lateral preoptic area (LPOA), magnocellular preoptic area, bed nucleus of the stria terminalis, ventral tegmental area (VTA), substantia nigra, and central gray than did the ventral cuts.Previous research has suggested that the lateral efferents of the MPOA interact with the VTA in the control of maternal behavior. The results of the present experiment suggest that MPOA axons which descend directly to the brainstem via the ventral LH are not essential for maternal behavior. Our results are consistent with the view that an MPOA‐to‐LPOA‐to‐VTA circuit may be important for maternal behavior.
Inferior colliculus of the house mouse. I. A quantitative study of tonotopic organization, frequency representation, and tone‐threshold distribution
Authors: Stiebler Imme , Ehret Günter 
Published: January 2005

AbstractElectrophysiological mapping was used to study frequency representation in the inferior colliculus (IC) of the mouse. In the lateral nucleus (LN) only part of the frequency range of hearing was represented and tonotopicity was separate from that in the rest of the IC. Highest frequencies occupied the medial part (M) of the central nucleus (CN). A single complete representation of the hearing range was present only if representations in the dorsal cortex (plus dorsomedial nucleus) and CN (including M) were combined. Continuous isofrequency planes making up these nuclei (without the lateral part of the CN) were reconstructed. They tilted from medial to lateral and from caudal to rostral. The steepness of the slopes increased from caudal to rostral and from dorsal to ventral (i.e., with increasing frequency). Isofrequency planes had similar angles of deviation from the horizontal plane as described for dendritic laminae in the CN. Differences of mapping in the lateral part of the CN from that in the rest of the CN could be explained by the different organization of laminae in this part.The relative e mounts of IC depth and volume occupied by parts of the mouse audible frequency range were quantified. Frequency representation along IC depth wan not proportional to that along cochlear length. Compared with the relative density of afferent nerve fiber supply within given frequency ranges represented along the basilar membrane, there is a relative under‐representation in the IC up to 15–20 kHz and an over‐representation of higher frequencies.Highest absolute tone sensitivity (lowest threshold) was found in neurons forming a column (running perpendicular to isofrequency planes) in the center of the IC.Results are discussed with regard to frequency representation, intrinsic neuronal organization, and functional segregation in the IC of mammals.
Morphology of retinogeniculate terminals in the turtle, pseudemys scripta elegans
Authors: Sjöströum Anne M. , Ulinski Philip S. 
Published: January 2005

AbstractThe dorsal lateral geniculate complex in turtles receives a bilateral, topographic projection from the retina and projects to the telencephalon. This study examined the morphology of individual retinogeniculate terminals that were filled with horseradish peroxidase by injections in the optic tract or optic tectum.A large number of retinogeniculate terminals were successfully filled and detailed drawings were prepared of 87 terminals. Terminals were classified into three types based on the size and number of varicosities in the terminal, and (if a terminal formed a spatially restricted arbor) the volume of the arbor. Type I retinogeniculate terminals form spatially restricted, large‐volume arbors with a low density of large varicosities. Type II retinogeniculate terminals form small volume arbors with a high density of small varicosities. Type III retinogeniculate terminals, in contrast to types I and II, do not form spatially restricted arbors. Rather, they consist of sparsely branched axons that parallel the optic tract and contain scattered en passant varicosities. Plots of the distribution of different terminal types throughout the geniculate complex show that all three terminal types occur throughout the rostrocaudal and mediolateral extents of the complex. However, each terminal type has a preferential distribution with type II terminals being concentrated in the outer half of the neuropile, type I terminals in the inner half of the neuropile, and type III terminals in the cell plate. All three types can arise from axons that continue caudally to terminate in the tectum.These findings raise the possibility that various classes of retinal ganglion cells differ in their mode of termination within the geniculate complex, but the precise relation between the three types of retinogeniculate terminals and the classes of ganglion cells remains to be determined.
Specificity of motoneuron projection patterns during development of the bullfrog tadpole (Rana catesbeiana)
Authors: Farel Paul B. , Bemelmans Sibyl E. 
Published: January 2005

AbstractThe pattern of connectivity between motoneurons of the lumbar lateral motor column (LMC) and hindlimb regions was examined in bullfrog tadpoles (Rana catesbeiana) over the course of larval development. The purpose of this study was to determine if a period of relatively imprecise connectivity, such has been found in the toad Xenopus laevis (Lamb, '76), could be identified. Patterns of connectivity were assessed by placing small amounts of the retrogradely transported enzyme horseradish peroxidase (HRP) into discrete hindlimb regions and mapping the locations of labeled motoneuron somata along the transverse and longitudinal axes of the LMC. The distribution of labeled motoneurons was as circumscribed in the youngest animals studied (st. IV of Taylor and Kollros, '46), before mesenchymal condensation into distinct myotubes, as in metamorphic or adult animals. This finding that the pattern of neuromuscular connectivity is as precise early in development as in mature animals is consistent with previous studies of chick hindlimb (Landmesser, '78). The relevance of these results to the hypothesis that naturally occurring cell death plays a substantial part in molding the mature pattern of neuromuscular connectivity (Lamb, '77) is discussed.
The organization of the diencephalon and the pretectum in the cichlid fish, Haplochromis burtoni
Authors: Fernald Russell D. , Shelton Linda C. 
Published: January 2005

AbstractAlthough teleost fish comprise the largest vertebrate radiation, surprisingly little is known about the structure and development of their central nervous systems. Since teleosts are being used much more frequently as model systems in neurobiological research, particularly in understanding visual function, detailed information is needed about central nervous system structures and interconnections. By using the Bodian method with Nissl counterstaining we have analyzed the major nuclei in the diencephalon and pretectum of a cichlid fish, Haplochromis burtoni, which is dependent on vision for its survival. Although our results are broadly comparable with those from other teleost species, there are clear differences, particularly among the visual nuclei. By using animals of a range of sizes to confirm our descriptions we were able to identify possible developmental relationships among several nuclei.
Multiple opioid peptides and the modulation of pain: Immunohistochemical analysis of dynorphin and enkephalin in the trigeminal nucleus caudalis and spinal cord of the cat
Authors: Cruz Lilia , Basbaum Allan I. 
Published: January 2005

AbstractUsing immunocytochemistry we have identified important differences in the distribution of immunoreactive dynorphin and enkephalin cells and terminals in the trigeminal nucleus caudalis and in the spinal dorsal horn of the cat. Dynorphin immunoreactive processes are more closely associated with those regions of cord that process nociceptive information, specifically laminae I and V. Enkephalin neurons and terminals are more widespread. Based on the staining pattern with an antiserum to the octapeptide‐met‐enkephalin‐arg‐gly‐leu, we suggest that the dense enkephalin terminal immunoreactivity in the inner part of the substantia gelatinosa derives from cells in lamina III. There are also significant differences in the anatomical relationship of the two opioid peptides with the organization of parasympatheic autonomic preganglionic neurons. The functional significance of these observations must await physiological analysis; nevertheless, it is almost certain that differences will be found and that these will be important in understanding the mechanisms through which exogenous opiates and a variety of descending control systems exert their effects on spinal cord neurons.