bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential distribution of exogenous BDNF, NGF, and NT‐3 in the brain corresponds to the relative abundance and distribution of high‐affinity and low‐affinity neurotrophin receptors
Authors: Anderson Keith D. , Alderson Ralph F. , Altar C. Anthony , DiStefano Peter S. , Corcoran Thomas L. , Lindsay Ronald M. , Wiegand Stanley J. 
Published: January 2005

AbstractTo evaluate effective means for delivering exogenous neurotrophins to neuron populations in the brain, we compared the distribution and transport of brain‐derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophin‐3 (NT‐3) following intracerebral delivery. Rats received an injection of radioiodinated or unlabeled neurotrophin into the lateral ventricle and were killed humanely after 1.5–24 hours. Other rats received continuous infusion of unlabeled neurotrophin into the lateral ventricle, the striatum, or the hippocampus for 3–14 days. The neurotrophins were detected by autoradiography or immunohistochemistry. There were striking differences between BDNF, NGF, and NT‐3 in their penetration through brain tissue. These differences occurred regardless of the site or method of delivery, but were most pronounced following a bolus intracerebroventricular (ICV) injection. After ICV injection, NGF was widely distributed in tissues around the ventricles and at the surface of the brain, whereas the penetration of BDNF into brain tissue was distinctly less than that of NGF, and the penetration of NT‐3 was intermediate. An ICV injection of NGF produced prominent but transient labeling of cells that contain the low‐affinity NGF receptor, whereas an injection of BDNF prominently labeled the ventricular ependyma. During ICV infusion (12 g/day), the distribution of BDNF was no greater than that observed after a 12‐g bolus injection. A sixfold increase in the amount of BDNF infused (72 g/day) produced a more widespread distribution in the brain and doubled the depth of penetration into periventricular tissues near the cannula. Corresponding to their differences in penetration, NGF was retrogradely transported by basal forebrain cholinergic neurons after ICV or intrastriatal delivery, whereas NT‐3 was transported by a few basal forebrain neurons after ICV delivery, and BDNF was rarely detected in neurons after ICV delivery. Delivery of BDNF directly to the striatum or the hippocampus labeled numerous neurons in nuclei afferent to these structures. In situ hybridization studies confirmed that the high‐affinity BDNF receptor (TrkB) was much more widely expressed in neurons than was the high‐affinity NGF receptor (TrkA). Moreover, mRNA for truncated forms of TrkB was expressed at high levels in the ependyma, the choroid epithelium, and the gray matter. It is likely that binding of BDNF to TrkB, which appears to be more abundant and ubiquitous than TrkA, restricts the diffusion of BDNF relative to that of NGF. © 1995 Wiley‐Liss, Inc.
An ultrastructural double‐label immunohistochemical study of the enkephalinergic input to dopaminergic neurons of the substantia nigra in pigeons
Authors: Medina Loreta , Keith D. Anderson , Ellen J. Karle , Keiner Anton 
Published: January 2005

AbstractElectron microscopic immunohistochemical double‐label studies were carried out in pigeons to characterize the ultrastructural organization and postsynaptic targets of enkephalinergic (ENK+) striatonigral projection. ENK+ terminals in the substantia nigra were labeled with antileucineenkephalin antiserum by using peroxidase‐antiperoxidase methods, and dopaminergic neurons were labeled with anti‐tyrosine hydroxylase antiserum by using silver‐intensified immunogold methods. ENK+ terminals on dopaminergic neurons were equal in abundance to ENK+ terminals on nondopaminergic neurons, although the former were typically somewhat smaller than the latter (mean size: 0.50 vs. 0.75 pm, respectively). ENK+ terminals were evenly distributed on the cell bodies and dendrites of dopaminergic neurons, and they were evenly distributed on dendrites but rare on perikarya of nondopaminergic neurons. Transection of the basal telencephalic output revealed that 75% of the nigral ENK+ terminals were of basal telencephalic origin. These telencephalic ENK+ terminals included over 80% of those smaller than 0.80 pm on dopaminergic neurons and smaller than 1.0 pm on nondopaminergic neurons, and none greater than this in size. Both telencephalic and the nontelencephalic ENK+ nigral terminals made predominantly symmetric synapses on nigral neurons. Although the basal telencephalic ENK+ terminals uniformly targeted dendrites and perikarya, nontelencephalic ENK+ terminals seemed to avoid perikarya. The results indicate that ENK+ striatonigral neurons in birds may directly influence both dopaminergic and nondopaminergic neurons of the substantia nigra. Based on similar data for substance Pcontaining striatonigral terminals, the roles of enkephalin and substance P in influencing nigral dopaminergic neurons may differ slightly, as they appear to target preferentially different portions of dopaminergic neurons. The overall results in pigeons are similar to those for ENK+ terminals in the ventral tegmental area in rats, suggesting that the synaptic organization of the ENK+ input to the tegmental dopaminergic cell fields is similar in mammals and birds. © 1995 Wiley‐Liss, Inc.
Ultrastructural and immunocytochemical observations on the superior olivary complex of the mustached bat
Authors: Vater Marianne 
Published: January 2005

AbstractThis study investigates the functional organization of the superior olivary complex of the mustached bat with classical transmission electron microscopy and postembedding immunocytochemistry for gamma‐aminobutyric acid (GABA) and glycine antisera in semithin serial sections. The ultrastructure and distribution of terminal types in the lateral superior olive (LSO) and the medial nucleus of the trapezoid body (MNTB) closely resemble that of other mammals; the organization within the medial superior olive (MSO) differs significantly. The differences concern the relative proportion of putatively inhibitory boutons, which appear as symmetrical synapses with flattened vesicles on MSO somata. In the bat, inhibitory boutons comprised 75–100% of perisomatic boutons, a value identical to that observed in the LSO. These terminals most likely arise from the MNTB. In other species, putatively inhibitory terminals form a much smaller proportion of perisomatic boutons in MSO. This difference suggests that in the bat MSO excitatory input to cell somata is considerably reduced and outweighed by inhibitory input. This suggestion is corroborated by immunocytochemical data. Glycine‐immunoreactive puncta encrust somata of LSO and MSO cells to a similar degree and in rather homogeneous patterns throughout these nuclei. Putatively GABAergic terminals are located inainly on distal dendrites of MSO and LSO cells. Regional variations in the density of GABA‐immunoreactive puncta in LSO suggest that different tonotopic zones are under differential modulatory influence. Both the LSO and MSO of the mustached bat contain significant amounts of putatively inhibitory projection cells. Coexistence of both antigens was commonly observed in subsets of cells. Quantitative analyses of labeling patterns and comparisons with other mammals suggest that the mix of neurotransmitters in projection cells of LSO and MSO is phylogenetically flexible, and thus the details of the functions of ascending pathways are species specific. In contrast to other mammals, the bat MSO forms parallel output pathways with excitatory and inhibitory components. Data are discussed in relation to specialized physiological response features. © 1995 Wiley‐Liss, Inc.
Variation and evolution of mammalian corticospinal somata with special reference to primates
Authors: Nudo R. J. , Sutherland D. P. , Masterton R. B. 
Published: January 2005

AbstractThe morphology of the somata originating the corticospinal tract was examined in 24 species of mammals to identify commonalities and major sources of variation among the different species. Horseradish peroxidase was applied to a hemisection of the spinal cord at the C1–C2 junction. After tetramethylbenzidine processing, the labeled somata throughout the cerebral cortex were plotted and counted. Then, 23 morphological characteristics of the corticospinal somata were examined, including their number, size, and density across the cortical surface.The results show that morphological characteristics of corticospinal somata are closely related to an animal's body, brain, and cerebral cortex size. That is, mammals with large neocortical surfaces tend to have larger as well as more corticospinal somata; mammals with large bodies tend to have corticospinal somata that are less densely distributed. Moreover, the probable increase in the ratio of local noncorticospinal somata to corticospinal somata implies that the evolution of the corticospinal tract was accomplished by an increase in “support” or “server” cells as well as an increase in the size of the tract itself.The results also show that several characteristics are reliably related to an animal's taxonomic classification and hence its ancestry. Comparisons among three mammalian lineages indicate that some characteristics may have changed uniquely in the anthropoid primate lineage, and thus, presumably, in the human lineage. The results suggest that if morphological characteristics of the corticospinal tract important in the evolution of the specialized motor abilities in anthropoid primates are sought, then examination of the role of changes in soma diameter, rostral (motor)/caudal (sensory) ratios of density, concentration, surface density, and volume density may be more instructive than examination of the total number of corticospinal neurons alone. © 1995 Wiley‐Liss, Inc.
Organization of the olfactory system in the adult zebrafish: Histological, immunohistochemical, and quantitative analysis
Authors: Byrd Christine A. , Brunjes Peter C. 
Published: January 2005

AbstractThe zebrafish, Danio rerio, is becoming an important model system for developmental studies. We have used a variety of histological techniques to characterize the adult structure of the olfactory system in this teleost to form a base for future developmental work. The olfactory epithelium in this fish contains ciliated and microvillar sensory neurons, microvillar supporting cells, secretory goblet cells, and basal cells, and the adjacent nonsensory epithelium contains ciliated supporting cells. The olfactory bulb is a diffusely organized structure with four laminae: olfactory nerve, glomerular, mixed mitral cell/plexiform, and granule cell layers. These structures and the synapses observed in the olfactory bulb are typical of what is found in other vertebrates. We also examined the distribution of several neurotransmitter markers (tyrosine hydroxylase, neuropeptide Y, dopamine‐β‐hydroxylase, and serotonin) in the olfactory bulb. Antibodies to neuropeptide Y, dopamine‐β‐hydroxylase, and serotonin labeled fibers in the olfactory bulb and cell bodies in caudal regions of the brain in distributions comparable to other species. Tyrosine hydroxylase immunoreactivity was observed in a set of intrinsic bulb neurons with extensive processes in the glomerular layer. In addition, the structural proteins glial fibrillary acidic protein and vimentin have distributions similar to those in the olfactory bulbs of other animals. Thus, the adult olfactory structures are analogous to the structures in other vertebrate animals in morphology and chemical neuroanatomy. This similarity, along with its numerous advantages for developmental studies, makes the zebrafish a good model for studies of olfaction and forebrain maturation. © 1995 Wiley‐Liss, Inc.
Acutely isolated and cultured cells from the electrosensory lateral line lobe of a gymnotiform teleost
Authors: Turner Ray W. , Borg Laurie L. 
Published: January 2005

AbstractThe present study established the morphological and immunocytochemical criteria necessary to identify neuronal and nonneuronal cells after dissociating select regions of the medullary electrosensory lateral line lobe of adult weakly electric fish (Apteronotus Zeptorhynchus). Cells dissociated from the pyramidal cell body layers of the centromedial and lateral segments exhibited similar characteristics in the acutely dissociated preparation and up to 14 days in culture. Basilar and nonbasilar pyramidal cells were tentatively identified according to a bipolar or monopolar process extension, and polymorphic cells by the extension of three or more processes and positive immunoreactivity for gamma‐aminobutyric acid. Nonneuronal cells were identified by the pattern of process arborization and positive immunolabel for gamma‐aminobutyric acid or glial fibrillary acidic protein. Neuronal cells increased in total number over the first 4 days and could appear for the first time on any day in culture. Individual pyramidal cells could maintain their morphology from the time of dissociation and over several days in culture. Pyramidal cell processes were phenotypically similar to apical and basal dendrites found in situ but were reduced in size and in the degree of process branching. These results indicate that dissociated adult apteronotid neurons can maintain a morphology sufficiently similar to that found in situ as to allow tentative identification, opening up a wide range of possibilities for studying the electrophysiological and regenerative properties of electrosensory neurons. © 1995 Wiley‐Liss, Inc.
Arcuate nucleus neurons that project to the hypothalamic paraventricular nucleus: Neuropeptidergic identity and consequences of adrenalectomy on mRNA levels in the rat
Authors: Baker Ross A. , Herkenham Miles 
Published: January 2005

AbstractThe possible role that the hypothalamic arcuate nucleus might play in mediating the increase in paraventricular nucleus corticotropin‐releasing hormone mRNA levels following adrenalectomy was investigated in two series of experiments. In the first series, in situ hybridization histochemistry was used to quantify levels of eight arcuate nucleus neuropeptide and neurotransmitter mRNAs in neurons that potentially relay adrenal steroid feedback to the paraventricular nucleus. In the second series of experiments, arcuate neuropeptidergic projections to the hypothalamic paraventricular nucleus were characterized using retrograde tracing in combination with in situ hybridization histochemistry. Despite an increase in paraventricular nucleus corticotropin‐releasing hormone (60%) and pituitary proopiomelanocortin mRNA levels (sixfold), arcuate mRNA levels for proopiomelanocortin, neuropeptide Y, somatostatin, galanin, dynorphin, tyrosine hydroxylase, glutamate decarboxylase, and the glucocorticoid receptor were unchanged 14 days following adrenalectomy. Neuropeptidergic characterization of arcuatoparaventricular projections was achieved by injection of the retrograde tracer fluorogold into the paraventricular nucleus; retrogradely labeled neurons were characterized with polyclonal antisera against fluorogold in combination with oligonucleotide probes directed against neuropeptide Y, proopiomelanocortin, or somatostatin. Out of these three arcuate neuropeptides, neuropeptide Y mRNA was contained in 18% of the fluorogold‐positive neurons in the arcuate, proopiornelanocortin mRNA was contained in 8%, and somatostatin mRNA was contained in 6%. Overall, the results from both experiments suggest that the arcuatoparaventricular neuropeptide Y, proopiomelanocortin, and somatostatin projections are not sensitive to a chronic (14 day) lack of adrenal steroids. These projections as well as the other arcuate neurotransmitter and neuropeptide systems appear not to contribute to the persistent elevations in paraventricular nucleus corticotropin‐releasing hormone mRNA levels or pituitary proopiomelanocortin mRNA levels found in 14 day adremlectomized rats. © 1995 Wiley‐Liss, Inc.This article is a US Government work and, as in the public domain in the United States of America.
The septal complex of the telencephalon of the lizard Podarcis hispanica. I. chemoarchitectonical organization
Authors: Font Cristian , Hoogland Piet V. , van der Zee Eefke Vermeulen , Pérez‐Clausell Jeús , Martínez‐García Fernando 
Published: January 2005

AbstractIn this paper we study the septal complex architecture in the lizard Podarcis hispanica (Lacertidae). Histochemical and immunohistochemical techniques were used to define the distribution of zinc (Timm stain), acetyl cholinesterase (AChase), gamma‐aminobutyric acid (GABA), tyrosine hydroxylase (TH), dopamine (DA), serotonin (5‐HT), and two neuropeptides: leu‐enkephalin (L‐ENK) and substance P (SP). These reactions delineate a coherent map of nine septal nuclei that are named with a topographical nomenclature: anterior, lateral, ventromedial, medial, dorsolateral, ventrolateral, and dorsal septal nuclei, nucleus septalis impar, and nucleus of the posterior pallial commissure.The anterior septal nucleus is characterized by intense reaction for zinc and the presence of fibers immunoreactive for GABA, 5‐HT, and L‐ENK, which form pericellular nests. The lateral septal nucleus shows intense reaction for zinc, a high density of GABA‐immunoreactive cells, and L‐ENK‐immunoreactive fibers forming basketlike figures around unstained somata. The ventromedial septal nucleus shows intense AChase reactivity, a dense network of 5‐HT‐immunoreactive fibers, and virtually no labeling for the other histochemical stains. The medial septal nucleus is defined by heavy reactivity for zinc, dense DA/TH and L‐ENK innervations, and the presence of L‐ENK‐immunoreactive cells. The dorsolateral septal nucleus shows intense AChase staining in the neuropile and a dense network of fibers immunoreactive for 5‐HT and DA/TH, but it shows low staining for zinc, The ventrolateral septal nucleus shows L‐ENK‐immunoreactive cells and a dense L‐ENK innervation, but low reactivity for zinc. The dorsal septal nucleus, intermingled with the fimbrial fibers, shows a dense population of GABA‐immunoreactive cells and terminals, but it is unreactive for zinc. Two subdivisions can be established in this dorsal septal nucleus: the dorsal part, intensely reactive for AChase and innervated by 5‐HT fibers, and the central part, which shows L‐ENK‐immunoreactive neurons and fibers without reactivity for either AChase or 5‐HT. The nucleus septalis impar, traversed by the fibers of the anterior pallial commissure (mildly reactive for zinc), shows reaction for AChase but low (if present) reactivity for the remaining markers. The nucleus of the posterior pallial commissure shows a generally low reactivity for the histochemical reactions employed.The distribution of these markers is similar to that found in other squamate reptiles and allows for a direct comparison with the septal formation of mammals. Such a comparison reintorces the view that the limbic system has undergone a conservative evolution within vertebrates. © 1995 Wiley‐Liss, Inc.
Effects of early periods of monocular deprivation and reverse lid suture on the development of cat‐301 immunoreactivity in the dorsal lateral geniculate nucleus (dLGN) of the cat
Authors: Kind P. C. , Beaver C. J. , Mitchell D. E. 
Published: January 2005

AbstractDuring certain sensitive periods early in postnatal life, the anatomical and physiological development of the central visual pathways of cats and monkeys can be affected by the nature of an animal's early visual experience. In the last few years, studies have been started on some of the molecular and biochemical events that underlie the many functional changes induced by early selected visual deprivation in the visual cortex of kittens. In this respect, the monoclonal antibody Cat‐301 provides a potentially powerful tool, because it recognizes in the cat dorsal lateral geniculate nucleus (dLGN) a proteoglycan associated with the surface of a particular class of cells, namely Y cells. In the dLGN, the Cat‐301 proteoglycan appears late in postnatal development, and its expression has been shown to be experience dependent in both the dLGN and visual cortex (M. Sur, D. Frost, and S. Hockfield, 1988, J. Neurosci. 8:874–882; A. Guimaraes, S. Zaremba, and S. Hockfield, 1990, J. Neurosci. 10:3014–3024).We have explored further the experience‐dependent nature of Cat‐301 expression in the dLGN with a view to establishing a biochemical correlate of the many functional changes induced by early monocular deprivation and its reversal in the kitten visual system. In addition to demonstrating differences in Cat‐301 expression between deprived and nondeprived laminae of the dLGNs of kittens monocularly deprived to only 4 or 5 weeks of age, the magnitude of the laminar difference was found to increase as the period of deprivation was extended. Moreover, monocularly deprived kittens that subsequently received long periods of reverse lid suture exhibited a reversal of the pattern of immunoreactivity, so that the greatest immunoreactivity occurred in laminae innervated by the initially deprived eye. However, possibly the most surprising and important finding was the extremely low levels of immunoreactivity observed in both A laminae of monocularly deprived animals that had received relatively short periods of reverse lid suture. These data suggest that Y cell development can be drastically altered depending on the time of initiation of the period of reverse lid suture and its duration. © 1995 Wiley‐Liss, Inc.
5′‐Nucleotidase in the rodent ventral striatum: Relation to the distribution of leu‐enkephalin, cell clusters, and infralimbic cortical innervation
Authors: Laubach Mark G. , Woodward Donald J. 
Published: January 2005

AbstractThe goal of this study was to determine the compartmental organization of 5′‐nucleotidase within the rodent ventral striatum and to compare the distribution of 5′‐nucleotidase with that of leu‐enkephalin, cell clusters, and infralimbic cortical innervation. In the core, 5′‐nucleotidase is present in several contiguous patchy structures that are in register with leu‐enkephalin compartments. In the shell, 5′‐nucleotidase is concentrated in a longitudinal band along the septal border. This “medial band” extends from the rostral pole of the ventral striatum to the bed nucleus of stria terminalis. The ventral portion of the medial band is in register with a cluster of cells, located medial to the most dorsal island of Cajella. A second 5′‐nucleotidase compartment along the border of the core and shell is in register with a cell cluster and is most evident at caudal levels of the ventral striatum. The innervation of the ventral striatum by the infralimbic cortex is denser in the shell than in the core. In the shell, fibers from the superficial layers of the infralimbic cortex tend to avoid the 5′‐nucleotidase‐rich cell clusters and terminate in areas of moderate 5′‐nucleotidase density. By contrast, fibers from the deep layers terminate in the ventral striatum without regard to the 5′‐nucleotidase‐rich cell clusters. Overall, the compartmental structure of 5′‐nucleotidase in the ventral striatum segregates projections from different layers of the infralimbic cortex. Dense 5′‐nucleotidase compartments are innervated by neurons in the deep layers of the infralimbic cortex. The area of moderate 5′‐nucleotidase density surrounding the 5′‐nucleotidase compartments is innervated by neurons in both the superficial and deep layers. © 1995 Wiley‐Liss, Inc.