bluuebunny/crossref_metadata_2025 huggingface dataset:
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

In 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

During 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

The 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.
Parallel pathways and convergence onto HVc and adjacent neostriatum of adult zebra finches (Taeniopygia guttata)
Authors: Fortune Eric S. , Margoliash Daniel
Published: January 2005

The structure and connectivity of the forebrain nucleus HVc, a site of sensorimotor integration in the song control system of oscine birds, were investigated in adult zebra finches. HVc in males comprises three cytoarchitectonic subdivisions: the commonly recognized central region with large and medium‐sized darkly staining cells, a ventral caudomedial region with densely packed small and medium‐sized cells, and a dorsolateral region with oblong cells and rows of cells. All three subdivisions project to area X and the robust nucleus of the archistriatum, with more complexity in the classes and distribution of cells than previously reported. In females, HVc is very small and has a cytoarchitecture distinct from that of the three male subdivisions. The structure of HVc in females treated with estradiol at 15 days of age is similar to male HVc.

Tracer studies in males with fluorescent and biotinylated dextrans demonstrate non‐topographic projections onto HVc that may carry auditory information, including type 1 and type 2 neurons in subdivisions L1 and L3 of the field L complex, a class of neurons in nucleus interface, nucleus uvaeformis, the caudal neostriatum ventral to HVc, and intrinsic HVc connections. These data are interpreted in terms of HVc's functional properties. Additionally, the neostriatum immediately ventral to HVc receives projections from field L, ventral hyperstriatum, and caudal neostriatum, and projects to a region surrounding RA and near to or into area X. The similarity of the connectivity of HVc and adjacent neostriatum suggests the possibility that they share a common origin. © 1995 Wiley‐Liss, Inc.
Asymmetrical blastomere origin and spatial domains of dopamine and neuropeptide Y amacrine subtypes in Xenopus tadpole retina
Authors: Huang Sen , Moody Sally A.
Published: January 2005

Amacrine cells are located almost exclusively in the inner nuclear layer (INL) of the retina, but they express a variety of neurotransmitters. To begin to elucidate the relative roles of the local environment and cell lineage in determining the different neurotransmitter subtypes of amacrine cells, we combined lineage tracing and immunocytochemical techniques to map the spatial distribution and clonal origin of dopamine (DA) and neuropeptide Y (NPY) amacrine cells in Xenopus tadpole retina. At the earliest period of neurotransmitter expression, both DA and NPY amacrine cells were distributed preferentially in center and intermediate annular regions, and in anterior and dorsal quadrants. Most of the DA and NPY cells first emerged as scattered cells and later as clusters (of 2 or more cells) that increased in number and size up to premetamorphic stages. These results suggest that DA and NPY amacrine subtypes may be influenced by environmental cues localized to specific regions of the retina. Lineage analysis showed that the percentage of DA or NPY amacrine cells produced by most blastomere progenitors is significantly different from that predicted by the number of cells in the retina produced by those blastomeres. Only two blastomeres produced over 90% of the DA amacrine cells and only four produced 97% of the NPY amacrine cells. Some retinal progenitors did not contribute at all to these two amacrine subtypes. There also is a marked asymmetry in the blastomere origin of DA and NPY amacrine cells. Two retinal progenitors produced significant numbers of NPY but very few DA amacrine cells. This analysis provides evidence that blastomere origin restricts the developmental choices of retinal progenitors. © 1995 Wiley‐Liss, Inc.
Distribution of small vasopressinergic neurons in golden hamsters
Authors: Ferris Craig F. , Delville Yvon , Miller Margaret A. , Dorsa Daniel M. , De Vries Geert J.
Published: January 2005

In rats, small (diameter: ca. 10 μm) vasopressinergic neurons have been localized in the forebrain, including extrahypothalamic sites, such as the bed nucleus of the stria terminalis (BST) and the medial amygdala (MeA). In golden hamsters, no such neurons have ever been described in extrahypothalamic sites, while their presence in some hypothalamic sites, such as the paraventricular nucleus (PVN), remains controversial. The present studies were carried out to confirm the existence of small vasopressinergic neurons in the forebrain of golden hamsters, using rats as a positive control. The presence of small vasopressinergic neurons in these sites was first tested by imrnunocytochemistry in colchicine‐treated animals. The resulting distribution was corroborated by in situ hybridization for vasopressin (AVP) mRNA. While a large number of small AVP‐immunoreactive (AVP‐ir) neurons was found in the BST and MeA of colchicine‐treated rats, none was found in the same locations in hamsters. Interestingly, as a few large (diameter: 20–25 μm) AVP‐ir neurons were found in the BST just medial to the small neurons in rats, the same area contained a few large and small AVP‐ir neurons in hamsters. In the PVN, large and small AVP‐ir neurons were found in rats and hamsters. However, three to four times more neurons were counted in rats. These data were confirmed by in situ hybridization. Indeed, in hamsters, no labelling for AVP mRNA was detected in small neurons within the BST and MeA. Furthermore, the PVN of rats contained more labelling for AVP mRNA, as compared to hamsters. These results confirm that the distribution of vasopressiner gic neurons in rats cannot be generalized to other species without a detailed analysis. © 1995 Wiley‐Liss, Inc.
Distinct morphological characteristics of touch, temperature, and mechanical nociceptive neurons in the crotaline trigeminal ganglia
Authors: Liang Yun‐Fei , Terashima Shin‐Ichi , Zhu Al‐Qing
Published: January 2005

Intrasomal recording and horseradish peroxidase injection techniques were employed in vivo to determine the morphological characteristics of touch, temperature, and mechanical nociceptive neurons in the trigeminal ganglia of crotaline snakes. The touch neurons, with a peripheral axon conducting at the A–β range, could be subdivided into tactile and vibrotactile neurons according to their response properties, but there were no morphological differences between them. These neurons exhibited a large and oval soma and possessed a set of large stem, peripheral, and central axons which were all myelinated and equal in diameter with a constriction at the bifurcation. The temperature neurons, which conducted peripherally at the A‐δ; range, were physiologically separated into thermosensitive and thermo‐mechanosensitive neurons, which were also morphologically indistinguishable. The temperature neurons had a round soma of medium size and a set of medium axons with varied axonal bifurcation patterns. All axons of these neurons were myelinated, but the central axon was thinner than the stem and peripheral axons. The mechanical nociceptive neurons, which had a peripheral axon conducting at the A‐δ range, were morphologically heterogeneous based on their conduction velocities. The neurons conducting at the fast A‐δ range were morphologically similar to the temperature neurons in the ganglion excepting their thinner central axons, whereas those at the slow A‐δ range had a thinner myelinated stem axon that gave rise to a thinner myelinated peripheral axon and an unmyelinated central axon with a bifurcation of either a triangular expansion at the bifurcating point or a central axon arising straightforwardly from the constant stem and peripheral axons. This study revealed that distinct morphological characteristics do exist for the touch and temperature neurons and the subtypes of mechanical nociceptive neurons in the trigeminal ganglion, but not for the subfunctional types of touch neurons or temperature neurons. © 1995 Wiley‐Liss, Inc.
Non‐uniform distribution of cellular phenotypes in the optic tectum of the leopard frog
Authors: Debski Elizabeth A. , Liu Qin , Chapman Angela M.
Published: January 2005

Regional specializations in the retina have been described in a number of species. We have investigated whether such specializations can be found in the optic tectum, an area of the brain responsible for the processing of visual information. Using the tectum of Rana pipiens, we have examined the distribution of three different cell types defined on the basis of their immunoreactivity to somatostatin, substance P, and serotonin antibodies. These three immunoreactive cell populations had differing, nonuniform distributions in the optic tectum. Somatostatin‐like irnmunoreactive cells were largely restricted to the caudal one‐third of the tectum, whereas both substance P‐like immunoreactive (SP‐ir) and serotonin‐like immunoreactive (5‐HT‐ir) cells were found unequally represented throughout the tectum. The percentage of SP‐ir cells decreased significantly in both the posterior and medial directions from its high in the anterior lateral tectum. Although serotonin‐like immunoreactivity was also greatest in the lateral tectum and decreased significantly medially, it was largely constant in the anterior‐to‐posterior dimension. The populations of SP‐ir and 5‐HT‐ir cells were nonoverlapping. Our results suggest that information may be processed differently in different regions of the optic tectum. © 1995 Wiley‐Liss, Inc.
Two rules for callosal connectivity in striate cortex of the rat
Authors: Lewis James W. , Olavarria Jaime F.
Published: January 2005

In the rat, callosal cells occupy lateral as well as medial portions of striate cortex. In the region of the border between areas 17 and 18, which contains a representation of the vertical meridian of the visual field, cells projecting through the corpus callosum are concentrated throughout the depth of the cortex. In contrast, in medial portion of striate cortex, where peripheral portions of the visual field are represented, callosal cells are preferentially found in infragranular layers. These differences in topography and laminar distribution suggest that these callosal regions, referred to as medial and lateral callosal regions in the present study, subserve different functions. We explored this possibility by analyzing the patterns of callosal linkages in these two cailosai regions. We charted the location of retrogradely labeled cells within striate cortex of one hemisphere after placing restricted injections of one or more fluorescent tracers into selected sites in the contralateral striate cortex.

We found the medial and lateral callosal regions have distinctly different topographic organizations. Injections into medial striate cortex of one hemisphere produced labeled cells predominantly in mirror‐symmetric loci in medial portions of contralateral striate cortex. The arrangement of these connections suggests that they mediate direct interactions between cortical regions representir visual fields located symmetrically on opposite sides of the vertical meridian of the visual field. In contrast, the mapping in the lateral callosal region is reversed: injections into the 17/18a border produced labeled fields located medial to the contralateral 17/18a border, while injections slightly medial to the 17/18a border produced labeled fields located at the contralateral 17/18a border. Assuming that lateral striate cortex represents aportion of the ipsilateral visual field, this reversal in the callosal mapping suggests that callosal fibers in the lateral callosal region interlink cortical loci representing similar portions of the visual field. © 1995 Wiley‐Liss, Inc.
Distribution of brainstem projections from spinal lamina I neurons in the cat and the monkey
Authors: Craig A. D. (Bud)
Published: January 2005

The distribution of terminal projections in the brainstem from lamina I neurons in the spinal dorsal horn was investigated with the anterograde tracerPhaseolus vulgaris–leucoagglutinin in the cat and the cynomolgus monkey. Iontophoretic injections made with physiological guidance were restricted to lamina I or to laminae I–III in the cervical (C6–8) or lumbar (L6–7) enlargement. The distribution of terminal labeling was essentially identical in the cat and the monkey, although consistently of greater intensity in the monkey. Terminations were observed in the solitary nucleus, the dorsomedial medullary reticular formation, the entire rostrocaudal extent of the ventrolateral medulla, the locus coeruleus, the subcoerulear region and the Kölliker–Fuse nucleus, the lateral and medial portions of the parabrachial nucleus, the cuneiform nucleus, the ventrolateral and lateral portions of the periaqueductal gray, and the intercollicular nucleus. Lamina I terminations were generally bilateral in the medulla but more dense contralaterally in the pons and mesencephalon. The density and laterality of labeling in the medulla varied between cases independently from that in the pons and mesencephalon, suggesting that the lamina I projections to these regions may originate from different subsets of neurons. A clear topographic organization was observed only in the lateral column of the periaqueductal gray, where lumbar lamina I terminations were found caudal to cervical terminations.

These observations indicate that spinal lamina I neurons project to a variety of brainstem sites involved in autonomic (cardiovascular, respiratory) and homeostatic processing and the control of behavioral state. These projections provide an afferent substrate for spino‐bulbo‐spinal somatoautonomic reflex arcs activated by nociceptive, thermoreceptive activity and for a spino‐bulbo‐hypothalamic relay of such activity by cells in the caudal ventrolateral medulla. These observations support the general concept that lamina I projections distribute modality‐selective sensory information relevant to the physiological status and maintenance of the tissues and organs of the entire organism. © 1995 Wiley‐Liss, Inc.
Evidence for muscarinic acetyicholine receptor subtypes in the pigeon telencephalon
Authors: Kohler Emlee C. , Messer William S. , Bingman Verner P.
Published: January 2005

At least five subtypes of muscarinic acetyicholine receptors are expressed in various mammalian tissue preparations. The following experiment, through the use of direct binding assays (using tritiated quinuclidinyl benzilate), competitive binding assays (using tritiated quinuclidinyl benzilate and unlabeled pirenzepine or AF‐DX 116), and autoradiographic techniques, examined whether two of these five putative muscarinic acetylcholine receptor subtypes can be found in avian brain. Accordingly, autoradiographic mapping of pirenzepine sensitive (M1‐like) and AF‐DX 116‐sensitive (M2‐like) muscarinic acetylcholine receptor subtypes in the pigeon telencephalon was condu Although both ligands bound throughout the brain, most telencephalic regions, including the archistriatum, the neostriatum, and basal ganglia structures like lobus paraolfactorius, nucleus accumbens, and paleostriatum, showed a higher density of M1‐like sites. The exception to this finding was the nucleus basalis which appeared as a region where M2‐like sites predominated. Moreover, the telencephalic region with the largest ratio of M1‐like to M2‐like sites was the lateral portion of the parahippocampus; a characteristic shared with the mammalian dentate gyrus. The findings reported here are generally consistent with previous reports of mammalian M1/M2 receptor distributions. © Wiley‐Liss, Inc.
Large retinal ganglion cells in the channel catfish (Ictalurus punctatus): Three types with distinct dendritic stratification patterns form similar but independent mosaics
Authors: Cook J. E. , Sharma S. C.
Published: January 2005

Retinal ganglion cells in the channel catfish (Ictalurus punctatus) were retrogradely labelled, and those with the largest somata and thickest primary dendrites were categorized by their levels of dendritic stratification. Three types were found, each forming a mosaic making up ∼ 1% of the ganglion cell population. Using a system based on established sublaminar terminology, we call these the alpha‐a (αa), alpha‐b (αb), and alpha‐c (αc) ganglion cell mosaics. Cells of the αa mosaic had large, sparsely branched trees in sublamina a at 10–30% of the depth of the inner plexiform layer (IPL), sclerad to those of all other large ganglion cells. Some αa somata were displaced into the IPL or inner nuclear layer (INL) but belonged to the same mosaic as their orthotopic counterparts. Cells of the αa mosaic had dendrites that branched a little more and arborized in sublamina b at 50–60% of the IPL depth. Many also sent fine branches into sublamina a, and some were fully bistratified in a and b. The αc cells arborized in the most vitread sublamina, sublamina c, at 80–95% of the IPL depth. The soma areas of the three types in the largest retina studied ranged between 139 μm2 and 670 μm2 with significant differences in the order αa > αc ≥ αb. Analyses based on nearest‐neighbour distance (NND) and on spatial auto‐ and cross‐correlograms showed that each mosaic was statistically regular and independent of the others. Mosaic spacings were similar for each type, giving mean NNDs of 242–279 μm in the largest retina and 153–159 μm in a smaller one. Correspondences between these mosaics, previously defined large ganglion cell types in catfish, and other mosaic‐forming large ganglion cells in fish and frogs are discussed along with their implications for neuronal classification, function, development, and evolution. © 1995 Wiley‐Liss Inc.
Migration of A7 immortalized astrocytic cells grafted into the adult rat striatum
Authors: Okoye Godwin S. , Powell Elizabeth M. , Geller Herbert M.
Published: January 2005

The A7 cell line is an SV4O large T antigen‐immortalized astrocyte cell line produced from the neonatal rat optic nerve. Previous studies have demonstrated that A7 cells provide a favorable environment for the survival and growth of cultured neurons and can also stimulate axonal growth after grafting into the rat striatum. The current study was designed to investigate whether A7 cells grafted into adult rat striatum can migrate away from the implantation site. A7 cells were labelled in culture by incorporation of bromodeoxyuridine (BrdU) or by expression of an alkaline phosphatase transgene. The labelled cells were then transplanted into the left striatum of normal adult rats by introducing a blunt‐end 22 gauge needle through a trephine hole. The rats were euthanized at periods of up to 30 days after grafting. The A7 cells did not appear to alter the cytoarchitecture of the surrounding brain parenchyma. Labelled A7 cells were observed in both gray and white matter areas, and many were located in areas free of damage due to the implantation procedure. The migration of the BrdU‐labelled A7 cells with respect to the implantation needle track was determined on coronal sections. The radial migration distance from the needle tract was similarly determined on horizontal sections. A7 cells migrated progressively longer distances with increasing survival time of the animals: The largest migration distance (1,125 ± 52 μ) occurred at 30 days after grafting with an estimated migration rate of 31 μm per day. There was no significant directional polarity in the migration of these cells within the striatum. Some of the labelled A7 nuclear profiles were associated with blood vessels, some appeared to be associated with fiber bundles within the striatum, and some were found within the gray matter without apparent association with any anatomical structure. These results demonstrate that A7 immortalized astrocytic cells migrate away from a single implantation site following grafting into the adult rat striatum to populate a large area of the striatum. © 1995 Wiley‐Liss Inc.
Relationships between the morphology and function of gastric‐ and intestine‐sensitive neurons in the nucleus of the solitary tract
Authors: Zhang Xueguo , Fogel Ronald , Renehan William E.
Published: January 2005

This study employed single cell recording and intracellular iontophoretic injection techniques to characterize and label gastric‐ and/or intestine‐sensitive neurons in the rat nucleus of the solitary tract (NST). It was possible to divide our sample of NST neurons into three broad groups based on their response to increased intra‐gastric and intra‐duodenal pressure. Group 1 cells (N=14) were excited by duodenal distention but were not responsive to gastric stimulation. Most of these intestine‐sensitive neurons exhibited a delayed tonic response to the stimulus. Group 2 neurons (N=13) were excited by gastric distention but were not sensitive to distention of the duodenum. The typical Group 2 neuron evidenced a rapid, phasic response to the distention stimulus. Group 3 neurons (N=29) responded to both gastric and duodenal stimulation. We found that the Group 2 neurons had greater dendritic length and more dendritic branch segments than the Group 1 or Group 3 neurons. Most of the Group 1 neurons were found in the subpostremal/commissural region of the NST, while the majority of the Group 2 neurons were in the gelatinous subnucleus and a disproportionate number of the Group 3 neurons were located in the medial subnucleus. The results of this investigation demonstrate that (1) there are relationships between the morphology and physiology of distention‐sensitive neurons in the NST, and (2) there are distinct functional differences between the gelatinous, medial and commissural subnuclei of this nucleus. © 1995 Wiley‐Liss, Inc.
Peripheral projections of rat primary sensory neurons immunoreactive for neurotrophin 3
Authors: Zhou X.‐F. , Rush R. A.
Published: January 2005

Sensory neurons can be classified into subpopulations based on a variety of characteristics, including their morphology and physiological modalities. Whether any of these classifications correlates with neurotrophic sensitivities has not been determined, We have recently reported that a subpopulation of large diameter sensory neurons of the rat contain neurotrophin 3‐like immunoreactivity (NT3‐ir). In this study, we have further characterised NT3‐ir sensory neurons by their size, segmental localization, and peripheral projections by combined techniques of retrograde tracing and immunohistochemistry. The size distribution showed that NT3‐ir was localised to a subpopulation of large‐diameter neurons ranging from 560 to 3,120 m Greater numbers of NT3‐ir neurons reside in trigeminal (43% of total), cervical (36%), and lumbar (39%) than in thoracic spinal ganglia (13–17%). In combination with Fluoro‐Gold retrograde tracing, it was found that about 30% of sensory neurons projecting to the tibial muscle were NT3‐ir, compared with 39% for tendon, 50% for whisker hair follicles, 17% for subdermis or epidermis, and only 1% for kidney or adrenal gland. These studies indicate that NT3‐ir sensory neurons mainly project to skin and muscles but not viscera. Thus, the characterization of NT3‐ir spinal sensory neurons suggests that large sensory neurons subserving proprioception and mechanoception require NT3 for the maintenance of normal function. © 1995 Wiley‐Liss, Inc.
Anuran dorsal column nucleus: Organization, immunohistochemical characterization, and fiber connections in Rana perezi and Xenopus laevis
Authors: Muñoz A. , Muñoz M. , González A. , Donkelaar H. J. Ten
Published: January 2005

As part of a research program on the evolution of somatosensory systems in vertebrates, the dorsal column nucleus (DCN) was studied with (immuno) histochemical and tract‐tracing techniques in anurans (the large green frog, Rana perezi, and the clawed toad, Xenopus laevis). The anuran DCN contains some nicotinamide adenine dinucleotide phosphate diaphorase positiye neurons, very little calbindin D‐28k, and a distinct parvalbumin‐positive cell population. The anuran DCN is innervated by primary and non‐primary spinal afferents, by primary afferents from cranial nerves V, VII, IX, and X, by serotonin‐immunoreactive fibers, and by peptidergic fibers. Non‐primary DCN afferents from the spinal cord appear to arise throughout the spinal cord, but particularly from the ipsilateral dorsal gray. The present study focused on the efferent connections of the DCN, in particular the targets of the medial lemniscus. The medial lemniscus could be traced throughout the brainstem and into the diencephalon. Along its course, the medial lemniscus gives off collaterals to various parts of the reticular formation, to the octavolateral area, and to the granular layer of the cerebellum. At mesencephalic levels, the medial lemniscus innervates the lateral part of the torus semicircularis as well as various tegmental nuclei. A striking difference between the two species studied is that while in R. perezi medial lemniscal fibers do not reach the tectum mesencephali, in X. laevis intermediate and deep tectal layers are innervated. Beyond the midbrain, both dorsal and ventral thalamic areas are innervated by the medial lemniscus. The present study shows that the anuran “lemniscal pathway” is basically similar to that of amniotes. © 1995 Wiley‐Liss, Inc.
Structural and functional characterization of a muscle tendon proprioceptor in lobster
Authors: Combes Denis , Simmers John , Moulins Maurice
Published: January 2005

A morphological and electrophysiological study was made on a unique primary mechanosensory neuron, the anterior gastric receptor (AGR), previously shown to arise from powerstroke muscle gm1 of the gastric mill system in the lobster foregut. Ultrastructural analysis of horseradish peroxidase injected AGR demonstrated that its peripheral dendrites do not ramify in muscle but are confined strictly to the connective tissue/epidermal interface in the tendon of gm1. These terminals are rich in mitochondria and at their very endings are free of glial cell wrapping, suggesting that they are the site at which mechanotransduction occurs. Extracellular axonal recordings from an in vitro neuromuscular preparation consisting of the gm1 muscle still attached to the stomatogastric nervous system, revealed that AGR is activated by passive stretch of gm1. The response to ramp stimuli displays dynamic and static components, both of which increase with the amplitude of applied stretch, while the dynamic component is also velocity sensitive. AGR is also activated by muscle contraction here elicited either by application of exogenous acetyicholine, the excitatory neurotransmitter for gm 1, or by electrical stimulation of the motoneurons (GM) themselves. Consistent with a receptor lying in‐series with its muscle, therefore, the effective stimulus of AGR in vivo is probably an increase in tension exerted on the tendon during active muscle contraction. In neuromuscular preparations including the bilateral commissural ganglia, stretching gm1 reflexly activates GM motoneurons at low stimulus strengths but leads to an inactivation of GM motoneurons at high stimulus strengths. This is consistent with earlier findings that both responses can be elicited by direct electrical stimulation of AGR. The functional implications of AGR's anatomical relationship with muscle gm 1, the receptor's response properties, and its central effeet8 on motor output to gm1 are discussed. Comparison is also drawn between this first reported example of a true tendon receptor in invertebrates and muscle receptors of vertebrates. © 1995 Wiley‐Liss, Inc.
Morphogenesis of the photoreceptive site and development of the electrical responses in the butterfly genital photoreceptors during the pupal period
Authors: Miyako Yumiko , Arikawa Kentaro , Eguchi Eisuke
Published: January 2005

This paper describes the process of morphogenesis of the photoreceptive site of the butterfly genital photoreceptors. Associated development of the electrical responses is also described. The photoreceptor is a sensory neuron whose cell body is located in the genitalia and has a photoreceptive site of the phaosome‐type. This consists of the distal processes and the tubular membranes, which protrude from the tip of distal processes.

Phaosome morphogenesis was studied using electron microscopy. The results indicate that morphogenesis occurs in the latter half of the pupal period and that the process is divided into five phases. First, the tubular membranes appear as small membrane protrusions (phase I). The short tubular membranes emerge from several portions of the cell body forming several membrane clusters (phase II). The clusters then collect to form a small phaosome. Short distal processes become evident (phase III). The phaosome volume increases, mainly due to the extensive elongation and bifurcation of both tubular membranes and distal processes (phase IV). Phase V achieves fii adult morphology. The photoreceptors of phase II are already able to produce spikes in response to light stimulation, although the sensitivity was about one tenth of the adult. The sensitivity increase occurred in parallel with the increase in the phaosome volume. © 1995 Wiley‐Liss, Inc.
Serotonergic innervation of the lateral geniculate nucleus of the rat during postnatal development: A light and electron microscopic immunocytochemical analysis
Authors: Dinopoulos A. , Dori I. , Parnavelas J. G.
Published: January 2005

The serotonergic innervation of the developing lateral geniculate nucleus of the rat was studied with immunocytochemical techniques at the light and electron microscope levels. A relatively small number of thick serotonergic fibers were observed at the time of birth, distributed more densely in the ventral portion of the nucleus and in the intergeniculate leaflet than in the dorsal lateral geniculate nucleus. By the end of the first postnatal week, this distribution pattern was more clearly established, but the number of immunoreactive fibers was increased. Thereafter, and until the adult pattern was estabiished at the end of the third postnatal week, serotonergic fibers increased further in number and changed morphologically (e. g., they became finer and more ramified with closely spaced varicosities), but their pattern of distribution remained unchanged.

Electron microscopical analysis of the dorsal lateral geniculate nucleus revealed that the vast majority of serotonin varicosities formed asymmetrical synapses with dendritic shafts; axosomatic synapses were a feature of the nucleus only at the time of birth. The proportion of serotonin varicosities forming synapses increased gradually from birth to reach a peak at the end of the second post week, then declined markedly in the following week before increasing again at a later stage. It may be speculated that synapses formed during the first two weeks of life may be related to the involvement of serotonin in the morphogenesis of the lateral geniculate nucleus, whereas those formed later in development may be involved in the mediation of neurotransm effects. © 1995 Wiley‐Liss, Inc.
Observations on the weight and length of the central nervous system and of the legs in frogs, of different sizes (Rana virescens brachycephala– cope)
Authors: Donaldson Henry H. , Schoemaker Daniel M.
Published: January 2005

The males of Rana virescens brachycephala rarely attain a body weight above 50 grms. The females (without ovaries) may weigh 75 grams or more.

When the average of the largest males is compared with females yielding the same average weight, the males are found to have the lighter brain and spinal cord.

Spring frogs tend to lose weight rapidly when kept in the laboratory. This tendency diminishes as the season advances toward autumn.

In Rana virescens brachycephala the relative weight of the brain compared to that of the spinal cord decreases as the frog increases in size.

The weight of the leg muscles compared with the weight of the entire frog increases in small frogs up to about 5 grms. of body weight and then slightly decreases as the frog increases in size. In individuals of all sizes, the muscles of the thigh weigh from 1.78 to 1.80 times as much as those of the rest of the leg.

In frogs of all sizes, the sum of the lengths of the leg bones is a nearly constant fraction of the length of the entire frog. The proportional lengths of the several bones are also nearly constant.
Inhibition of prostaglandin synthesis by topically applied flurbiprofen in human primary irritant dermatitis
Authors: Kassis Vibeke , Søndergaard Jørgen
Published: January 2005

The inhibitory effect of topically applied flurbiprofen, a newer nonsteroidal antiinflammatory agent, on prostaglandin biosynthesis in human skin biopsies in primary irritant dermatitis was examined. The flurbiprofen‐treated areas synthesized significantly less PGE1 (279 pg/mg dry weight) than placebo‐treated inflamed skin (626 pg/mg dry weight). The average inhibition in 11 treated patients was 55% (P < 0.01 with Wilcoxon's signed rank test). Furthermore the anti‐inflammatory effect of flurbiprofen was clinically evaluated, and a poor correlation was found between the reduction of prostaglandin synthesis and the clinical effects of flurbiprofen.
Repeated acquisition of three‐response chains for food reinforcement in the rat
Authors: Pollard Gerald T. , McBennett S. Teresa , Rohrbach Kenneth W. , Howard James L.
Published: January 2005

Adult male hooded rats responding on three contact sensors for food reinforcement were trained to acquire a different three‐response sequence each day. Twelve three‐response sequences were used; with minor exceptions, the series of 12 was run four times in two rats and twice in one rat. Elapsed time and error rate for a given sequence declined over sessions and within sessions. Some sequences generated higher error rates than others. Results were generally consistent with previous results from pigeons emitting four‐response sequences. Application to the testing of drugs for therapeutic effects on cognitive deficits associated with aging is discussed.
Inhibitors of mast cell‐mediated shock in the rat: Relationship to histamine and serotonin antagonism
Authors: Awouters Frans , Niemegeers Carlos J. E. , Janssen Paul A. J.
Published: January 2005

Thirteen compounds of heterogenous chemical structure and pharmacologic profile were studied in vivo in tests that measure antagonism of histamine and/or serotonin in the rat. These tests were the compound 48/80‐lethality test, skin reactions to histamine and serotonin, the PCA test, and tryptamine‐induced bilateral convulsions and tremors. The compounds were always administered orally with a time interval of 2 hr between dose and challenge, to allow quantitative comparisons between activities in different tests. Compounds that preferentially antagonize histamine in the skin test have the same potency rank in the histamine skin test and in the compound 48/80‐lethality test. This indicates not only that H1‐antagonism is sufficient to prevent compound 48/80‐induced lethal shock, but also that the basis of the protection is the maintenance of a sufficiently large intravascular fluid volume compatible with normal cardiovascular function. Inhibition of a serotonin‐induced increase of capillary permeability may also be sufficient to prevent lethal shock, although the ergoline derivatives were much weaker than expected. For full inhibition of PCA‐reactions, doses are required that exhibit effective antagonism of both serotonin and histamine. Antagonism of tryptamine‐induced bilateral convulsions and tremors, which is a centrally mediated effect, showed no clear relation to any of the peripheral actions that were investigated.
Heterocyclic GABA analogues as new selective inhibitors of astroglial GABA transport
Authors: Schousboe A. , Larsson O. M. , Hertz L. , Krogsgaard‐Larsen P.
Published: January 2005

A series of heterocyclic GABA analogues were tested as inhibitors of neuronal and glial GABA transport and GABA‐receptor binding. Four compounds were shown to be selective inhibitors of glial GABA uptake, and the inhibition was in each case of the competitive type. The compounds are: β‐proline, homonipecotic acid, and the bicyclic isoxazoles THPO and THAO, the Kj values for the glial uptake of these compounds were 400, 700, 550, and 600 μM, respectively. The two latter compounds may be putative anticonvulsant drugs since they are likely to cross the blood‐brain barrier, and since they almost exclusively interfere with glial GABA uptake, which presumably would lead to increased synaptic GABA levels in vivo.
Effects of tetrahydroisoquinolines on dopa decarboxylase and pyridoxal kinase
Authors: Ebadi Manuchair , Govitrapong Piyarat
Published: January 2005

The mechanism of the nullification of the therapeutic effects of levodopa by pyridoxine in parkinsonian patients is not known and is still a subject of much speculation. Among other suggestions, it has been proposed that pyridoxine and levodopa may form tetrahydroisoquinoline derivatives in vivo, which may in turn inhibit dopa decarboxylase or act as a false transmitter. This possibility was tested by synthesizing six tetrahydroisoquinoline derivatives and by studying their effects on dopa decarboxylase in brain homogenates. These compounds in concentrations of 50 mM did not inhibit dopa decarboxylase or pyridoxal kinase, which synthesizes pyridoxal phosphate.
A comparison of butyrophenone and tricyclic neuroleptics with narcotics in blocking withdrawal signs in rats continuously infused with morphine
Authors: Hynes Martin D. , Lal Harbans
Published: January 2005

Narcotic dependence was established in male rats by continuous infusion of morphine given in increasing concentrations. Termination of the morphine infusion resulted in the reliable occurrence of body shakes. Narcotic drugs, morphine, fentanyl, and methadone, blocked withdrawal body shakes in a dose‐dependent manner. The butyrophenone neuroleptics, haloperidol, benperidol, and azaperone, were also effective in reducing withdrawal body shakes at doses that do not produce side effects. Trifluoperazine and chlorpromazine, two tricyclic neuroleptics were effective in reducing withdrawal shakes only at high doses that produced side effects. The anti‐withdrawal action of morphine, haloperidol, benperidol, and azaperone but not of chlorpromazine and trifluoperazine was antagonized by naloxone.
Certain GABA mimetics reduce the affinity of anions required for benzodiazepine binding in a GABA‐reversible way
Authors: Squires Richard F.
Published: January 2005

Binding of 3H‐flunitrazepam to specific sites on rat‐brain membranes is anion‐dependent. In the absence of added ions, binding is reduced to less than 10% of maximum, and eight anions (Tris salts) were found to increase binding in a concentration‐dependent and saturable manner with affinity constants (Kd) ranging from 0.75 mM (phosphate) to 4.5 mM (chloride). The GABA mimetic THIP (200 μM) increases these Kd values from three‐ to 10‐fold, depending on the anion. The GABA mimetics isoguvacine and piperidine‐4‐sulfonic acid (P4S) increase the Kd values for chloride ion eight‐ to 10‐fold, while amino‐propanesulfonate and imidazole acetate produce smaller (2‐ to 4‐fold) increases. These effects of THIP on anion affinities are reversed in a competitive manner by GABA and muscimol. Although there is no correlation between the ability of the anions to enhance 3H‐flunitrazepam binding and their ability to substitute for chloride ion electrophysiologically, it seems possible that the ions bind to sites similar to the chloride channels associated with GABA receptors. All benzodiazepine receptors are probably coupled indirectly to GABA receptors through anion binding sites.
“Sudden death” in laboratory rats: Animal model of depression?
Authors: Porsolt R. D.
Published: January 2005

Rats when placed into a highly stressful swimming situation will frequently die within a matter of minutes. It has been suggested that death is due to experimentally induced “hopelessness.” The present paper describes procedures with which “sudden death” can be rapidly and reliably induced in laboratory rats and reports that four psychoactive drugs (imipramine, d‐amphetamine, chlordiazepoxide, and chlorpromazine) tested failed to affect survival time. It is concluded that the procedure is not useful for the screening of potential antidepressant or other kinds of psychotropic agent.