bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological diversity and glutamate immunoreactivity of retinal terminals in the suprachiasmatic nucleus of the cat
Authors: Chen Boqing , Pourcho Roberta G.
Published: January 2005

Although the cat visual system has been the subject of intensive investigation, little attention has been given to the morphological features of ganglion cell projections to the suprachiasmatic nucleus. The present study has utilized anterograde transport of horseradish peroxidase and wheat germ agglutinin–conjugated horseradish peroxidase to label ganglion cell terminals in the cat suprachiasmatic nucleus. Visualization of the reaction product was facilitated through the use of gold‐substituted silver intensification. Ganglion cell terminals were found to be morphologically diverse, making both asymmetric and symmetric contacts with postsynaptic processes. Synaptic vesicles were either scattered or densely packed, sometimes forming paracrystalline arrays. In contrast to other retinorecipient areas in which ganglion cell terminals have, been characterized by the presence of lightly staining mitochondria, many of the retinal terminals in the suprachiasmatic nucleus were seen to contain darkly stained mitochondria. Postembedding antiglutamate immunocytochemistry was used to evaluate the level of endogenous glutamate in these ganglion cell terminals. Although morphologically diverse, all of the retinal terminals in the suprachiasmatic nucleus were glutamate positive, consistent with the postulated role of glutamate as the neurotransmitter of retinal ganglion cells. © 1995 Wiley‐Liss, Inc.
Oculomotor control in calliphorid flies: Head movements during activation and inhibition of neck motor neurons corroborate neuroanatomical predictions
Authors: Gilbert Cole , Gronenberg Wulfila , Strausfeld Nicholas J.
Published: January 2005

In tethered flying flies, moving contrast gratings or small spots elicit head movements which are suited to track retinal images moving at velocities up to 3,000°/sec (about 50 Hz contrast frequency for gratings of spatial wavelength 15°). To investigate the neural basis of these movements we have combined videomicroscopy with electrophysiological stimulation and recording to demonstrate that excitation of prothoracic motor neurons projecting in the anterodorsal (ADN) and frontal nerves (FN), respectively, generates the yaw and roll head movements measured behaviorally. Electrical stimulation of the ADN produces head yaw. The visual stimuli which excite the two ADN motor neurons (ADN MNs) are horizontal motion of gratings or spots moving clockwise around the yaw axis in the case of the right ADN (counterclockwise for left ADN). Activity is inhibited by motion in the opposite direction. Spatial sensitivity varies in the yaw plane with a maximum between 0° and 40° ipsilaterally, but both excitation and inhibition are elicited out to 80° in the ipsilateral and contralateral fields. ADN MNs respond to contrast frequencies up to 15–20 Hz, with a peak around 2–4 Hz forgrating motion in the excitatory or inhibitory directions. Electrical stimulation of the FN primarily elicits roll down to the ipsilateral side. The one FN MN consistently driven by visual stimulation is excited by downward motion and inhibited by upward motion at 80° azimuth in the ipsilateral visual field. At −80° contralateral, visual motion has the opposite effect: Upward is excitatory and downward is inhibitory. The FN MN is tuned to contrast frequencies in the same range as the ADN MNs, with peak sensitivity around 4 Hz. The functional organization of inputs to the ADN and FN is discussed with respect to identified visual interneurons and parallel pathways controlling motor output. © 1995 Wiley‐Liss, Inc.
Oculomotor control in calliphorid flies: GABAergic organization in heterolateral inhibitory pathways
Authors: Strausfeld Nicholas J. , Kong Alberta , Milde Jürgen J. , Gilbert Cole , Ramaiah Lila
Published: January 2005

In calliphorid Diptera, motor neurons mediating visually evoked head movements can be excited or inhibited by visual stimuli, depending on the directionality of the stimulus and whether it is in the ipsi‐ or contralateral visual field. The level at which inhibition occurs is of special interest because binocular activation of homolateral tangential neurons in the lobula plate demonstrates that excitatory interaction must occur between the left and right optic lobes. Recordings and dye fillings demonstrate a variety of motion‐sensitive heterolateral pathways between the lobula plates, or between them and contralateral deutocerebral neuropil, which provides descending pathways to neck motor centers. The profiles of heterolateral tangential cells correspond to neurons stained by an antibody against γ‐aminobutyric acid (GABA). Other GABA‐immunoreactive interneurons linking each side of the brain correspond to uniquely identified motion‐sensitive neurons linking the deutocerebra. Additional inhibitory pathways include heterolateral GABAergic descending and ascending neurons, as well as heterolateral GABAergic neurons in the thoracic ganglia. The functional significance of heterolateral GABAergic pathways was tested surgically by making selective microlesions and monitoring the oculoniotor output. The results demonstrate an important new attribute of theinsect visual system. Although lesions can initially abolish an excitatory or inhibitory response, this response is reestablished through alternative pathways that provide inhibitory and excitatory information to the same motor neurons. © 1995 Wiley‐Liss, Inc.
The guidance molecule Semaphorin III is expressed in regions of spinal cord and periphery avoided by growing sensory axons
Authors: Wright D. E. , White F. A. , Gerfen R. W. , Silos‐Santiago I. , Snider William
Published: January 2005

The protein collapsin was purified from chick brain on the basis of its ability to inhibit sensory neuron growth cones, implicating this molecule in sensory axon guidance (Luo et al. [1993] Cell 75:217–227). To examine the relationship between collapsin and sensory axon growth, we examined the pattern of mRNA expression of collapsin's mammalian paralogue, Semaphorin III (Sema III), and compared it to dorsal root ganglion (DRG) axon pathways in the developing rat embryo. Centrally, DRG axons enter the spinal cord by embryonic (E) 11 and branch into the gray matter by E 15 in brachial and thoracic regions. Laminar specific targets are reached by E17. Between E13 and E17, Sema III mRNA is expressed at high levels in the entire ventral half of the spinal cord except the floor plate. This pattern suggests that Sema III may inhibit non‐proprioceptive sensory axons from penetrating the ventral spinal cord. Peripherally, sensory axons have entered the anterior sclerotome by E 11 at all rostrocaudal levels. At this age, Sema III mRNA is already expressed in the dermamyotome and ventral aspect of the posterior sclerotome, areas which axons pass between but do not penetrate en route to their peripheral targets. From E12 to E15, the axons lengthen and branch into smaller fascicles which extend toward peripheral targets. During this time, Sema III mRNA isexpressed by many mesodermal structures surrounding the axon fascicles, with highest levels observed in the dermamyotome, perinotochordal mesenchyme, pelvic girdle, and limb. As development proceeds, Sema III mRNA expression is quickly downregulated before disappear ing by birth. Taken together, our results demonstrate that the gene for Sema III is expressed in central and peripheral regions which are avoided by growing DRG axons. These findings are consistent with the idea tha Sema III inhibits growth and branching of axons into inappropri ate areas during development. © 1995 Wiley‐Liss, Inc.
Presence or absence of TrKA protein distinguishes subsets of small sensory neurons with unique cytochemical characteristics and dorsal horn projections
Authors: Molliver Derek C. , Radeke Monte J. , Feinstein Stuart C. , Snider William D.
Published: January 2005

Investigations into the biological actions of nerve growth factor (NGF) have shown that dorsal root ganglion (DRG) neurons subserving nociception require NGF for survival and maintenance of phenotype. This discovery suggests that the signaling NGF receptor, TrkA, can be used as a marker for nociceptive neurons. In this study, we have used antibodies to TrkA, in conjunction with cell biological markers that show a restricted distribution in the DRG, to further characterize subsets of DRG neurons that are dependent upon NGF. Staining for TrkA labeled small and medium‐sized neurons that composed 47% of all neurons in thoracic ganglia. Double‐labeling with antibodies to the high molecular weight neurofilament protein (NFH), a marker for neurons with myelinated axons, demonstrated that TrkA staining is found in only a small subset of myelinated neurons. Surprisingly, many DRG neurons were not labeled by either TrkA or NFH. These neurons had small soma areas, contained the intermediate filament protein peripherin, and were labeled by the lectin BSI, identifying them as neurons likely to have unmyelinated axons. In addition, small TrkA–negative neurons were extensively labeled by antibodies to the intermediate filament protein γ‐internexin, the delta isoform of protein kinase C, and by the BSI isolectin BSI‐B4. In order to assess the potential functions of TrkA–negative small neurons, we examined their projections to the dorsal horn of the spinal cord. TrkA–immunoreactivity in the spinal cord was restricted to lamina I and the outer region of lamina II (II0), similar to staining for calcitonin gene‐related peptide. In contrast, the central projections of TrkA–negative neurons, as visualized by BSI‐B4 staining, were particularly dense in lamina IIi. Our results suggest that TrkA‐expressing and non‐TrkA‐expressing small neurons compose functionally distinct populations of DRG neurons. © 1995 Wiley‐Liss, Inc.
Retinal neurons and vessels are not fractal but space‐filling
Authors: Panico Joseph , Sterling Peter
Published: January 2005

Many branched patterns in nature are hypothesized to be fractal, i. e., statistically self‐ similar across a range of scales. We tested this hypothesis on the two‐dimensional arbors of retinal neurons and blood vessels. First, we measured fractalness on synthetic fractal and nonfractal patterns. The synthetic fractal patterns exhibited self‐similarity over a decade of scale, but the nonfractal “controls” showed hardly any self‐similarity. Neuronal and vascular patterns showed no greater self‐similarity than the controls. Second, we manipulated a synthetic fractal pattern to remove its self‐similarity and found this to be reflected in a loss of measured fractalness. The same manipulation of the nonfractal control and also of the neural and vascular patterns did not alter their measured fractalness. Third, we “grew” patterns of branched line segments according to a variety of nonfractal algorithms. These patterns were, if anything slightly more fractal than the neural and vascular patterns. We conclude that the biological patterns studied here are not fractal. Finally, we measured extended versions of these patterns: a contiguous array of homotypic neuron arbors and a vascular pattern with a high degree of total detail. These patterns showed a “fractal dimension” of 2, which implies that down to some cut‐off scale they fill space completely. Thus, neural and vascular patterns might best be described as quasi‐regular lattices. © 1995 Wiley‐Liss, Inc.
The rod pathway of the macaque monkey retina: Identification of AII‐amacrine cells with antibodies against calretinin
Authors: Wässle Heinz , Grüunert Ulrike , Chun Myung‐Noon , Boycott Brian B.
Published: January 2005

AII‐amacrine cells were characterized from Golgi‐stained sections and wholemounts of the macaque monkey retina. Similar to other mammalian retinae, they are narrow‐field, bistratified amacrine cells with lobular appendages in the outer half of the inner plexiform layer (IPL) and a bushy, smoother dendritic tree in the inner half. AII cells of the monkey retina were stained immunocytochemically with antibodies against the calcium‐binding protein Calretinin. Their retinal mosaic was elaborated, and their density distribution across the retina was measured. Convergence within the rod pathway was calculated. Electron microscopy of Calretinin‐immunolabelled sections was used to study the synaptic connections of the AII cells. They receive a major input from rod bipolar cells, and their output is largely onto cone bipolar cells. Thus, the rod pathway of the primate retina follows the general mammalian scheme as it is known from the cat, the rabbit, and the rat retina. The spatial sampling properties of macaque AII‐amacrine cells are discussed and related to human scotopic visual acuity.© 1995 Wiley‐Liss, Inc.
Subdivisions of macaque monkey auditory cortex revealed by calcium‐binding protein immunoreactivity
Authors: Jones E. G. , Dell'Anna M. E. , Molinari M. , Rausell E. , Hashikawa T.
Published: January 2005

The aim of this investigation was to characterize auditory areas of the primate cerebral cortex on the basis of chemoarchitecture. Cortical areas of the supratemporal plane were delineated in Macaca fuscata (M. fuscata) by immunocytochemical staining for parvalbumin, staining for cytochrome oxidase, examination of cyto‐ and myeloarchitecture, and retrograde tracing of corticocortical connections. Comparative observations were made on Macaca fascicularis (M. fascicularis).

Differential staining of fiber plexuses, probably of thalamic origin, identifies a central core zone of dense iznmunostaining and a surrounding zone of moderate‐to‐dense immunostaining composed of anteromedial, lateral, and posteromedial fields. Outside the second zone, there is a third anterolateral zone of weaker immunoreactivity, and, outside that zone, there is a fourth zone in which immunoreactivity is virtually absent. Differences in parvalbumin immunostaining in the auditory fields may reflect differences in relative contributions of thalamic inputs from parvalbumin‐immunoreactive cells in the medial geniculate complex.

The central core zone and the surrounding three fields can be correlated with major auditory fields previously defined by multiunit mapping and thalamocortical connectivity. The core zone contains a large principal field and an anterior extension. The pattern of corticocortical connections between thse and adjoining fields suggests that the anteromedial, lateral, and posteromedial fields represent first steps in three streams of connections passing outward from auditory into association cortex.

M. fuscata has an unusually large auditory cortex that is more deeply placed in the lateral sulcus in comparison to that of M. fascicularis. A small annectant gyrus provides a guide to the position of the primary auditory area. © Wiley‐Liss, Inc.
Distribution of growth‐associated class I α‐tubulin and class II β‐tubulin mrnas in adult rat brain
Authors: Paden Charles M. , Zhou Xinrong , Watt John A. , Burton Rebecca , Pickett Judith , Oblinger Monica M.
Published: January 2005

A comprehensive survey of class I α‐tubulin (αl) and class II β‐tubulin (βII) mRNAs was performed using in situ hybridization in order to determine the extent of continued expression of these immature tubulin isotype mRNAs in the adult rat brain. Qualitatively similar distributions of the two isotype mRNAs were observed, with marked variations in hybridization intensity of both probes apparent across different brain regions. Neurons in a wide variety of structures throughout the brain exhibited intense hybridization signals. While the presence of large numbers of neurons with a moderate hybridization intensity could account for the relatively high level of total binding in some regions such as the cerebellar and dentate granule layers, in most cases higher regional mRNA levels reflected greater hybridization intensity per neuron. Little variability in hybridization intensity was typically seen between individual cells within specific nuclei throughout the brain. The presence of occasional intensely labeled neurons scattered throughout the basal ganglia provided the most striking exception to this pattern. While no qualitative differences between the distributions of αl‐tubulin and βII‐tubulin mRNAs were observed, consistent differences in the relative intensity of hybridization for α1‐tubulin versus βII‐tubulin mRNA were apparent in a few brain regions. Expression by glia did not appear to contribute significantly to detectable levels of either α1‐tubulin or βII‐tubulin mRNA. These findings suggest that continued expression of growth‐associated tubulin isotype mRNAs may have functional significance in specific neuronal populations of the adult brain. Partial overlap between the distributions of α1‐ and βII‐tubulin mRNAs and that of GAP‐43 mRNA is discussed, as are potential roles for growth‐associated tubulin gene expression in supporting cytoskeletal turnover, reactive axonal growth, and dendritic remodeling in the adult brain. © 1995 Wiley‐Liss Inc.
Fate of GABAergic septohippocampal neurons after fimbria‐fornix transection as revealed by in situ hybridization for glutamate decarboxylase mRNA and parvalbumin immunocytochemistry
Authors: Kermer P. , Naumann T. , Bender R. , Frotscher M.
Published: January 2005

Many septohippocampal neurons are GABAergic and are affected by transection of the fimbria‐fornix, like the septohippocampal cholinergic cells. Here we have studied the changes that occur in GABAergic septohippocampal neurons following fimbria‐fornix transection. For labeling of septohippocampal projection neurons, adult Sprague‐Dawley rats received injections of the fluorescent tracer Fluoro‐Gold into the hippocampus 1 week prior to bilateral transection of the fimbria‐fornix. After axotomy, rats were allowed to survive for varying periods ranging from 3 weeks to 18 months. Following fixation of the animals, sections through the septal region were either stained by in situ hybridization for glutamate decarboxylase (GAD) mRNA or immunostained for parvalbumin (PARV) which is known to be present in GABAergic septohippocampal neurons.

In situ hybridization for GAD mRNA revealed no statistically significant changes in cell number 3 weeks and 6 months postlesion. In contrast, PARV‐immunoreactive neurons were reduced to 35% of control 3 weeks postlesion. This value increased to 66% after 6 months of survival. As seen in the electron microscope, axotomized PARV‐positive neurons exhibited characteristics of vital cells. Most neurons contained lysosomes associated with Fluoro‐Gold, resulting from retrograde labeling prior to fimbria‐fornix transection.

We conclude that mainly PARV‐containing GABAergic neurons in the medial septal nucleus (MS) project to the hippocampus and are thus heavily affected by the lesion but are able to survive and restore the synthesis of PARV. The lack of significant changes in the number of GAD mRNA‐expressing cells is explained by the presence of numerous GABAergic MS neurons not projecting to the hippocampus. © 1995 Wiley‐Liss Inc.
Subsets of midbrain dopaminergic neurons in monkeys are distinguished by different levels of mRNA for the dopamine transporter: Comparison with the mRNA for the D2 receptor, tyrosine hydroxylase and calbindin immunoreactivity
Authors: Haber S. N. , Ryoo H. , Cox C. , Lu W.
Published: January 2005

The midbrain dopamine system can be divided into two groups of cells based on chemical characteristics and connectivity. The dorsal tier neurons, which include the dorsal pars compacta and the ventral tegmental area, are calbindin positive, and project to the shell of the nucleus accumbens. The ventral tier neurons are calbindin‐negative and project to the sensonmotor striatum. This study examined the distribution of the mRNAs for the dopamine transporter molecule (DAT) and the D2 receptor in the midbrain of monkeys by using in situ hybridization. The distribution patterns were compared to that of tyrosine hydroxylase and calbindin immunohistochemistry. The results show that high levels of hybridization for DAT and the D2 receptor mRNA are found in the ventral tier, calbindin‐negative neurons and relatively low levels are found in the dorsal, calbindin‐positive tier. Within the dorsal tier, the dorsal substantia nigra pars compacta has the least amount of both messages. These results show that in monkeys, the ventral tegmental area and the dorsal pars compacta form a dorsal continuum of dopamine neurons which express lower levels of mRNA for DAT and D2 receptor than the ventral tier. DAT has been shown to be involved in the selective neurotoxicity of N‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP). Different levels of DAT mRNA and calbindin may explain the differential effects of MPTP neurotoxicity. © 1995 Wiley‐Liss Inc.
Interdigitation of nitric oxide synthase‐, tyrosine hydroxylase‐, and serotonin‐containing neurons in and around the laterodorsal and pedunculopontine tegmental nuclei of the guinea pig
Authors: Leonard C. S. , Kerman I. , Blaha G. , Taveras E. , Taylor B.
Published: January 2005

The topography of neurons containing nitric oxide synthase (NOS) and monoamines was investigated in the guinea pig mesopontine tegmentum. NOS‐containing neurons were identified with NADPH‐diaphorase (NADPH‐d) histochemistry, and monoamine‐containing neurons were identified with tyrosine hydroxylase (TH) and serotonin (5‐HT) immunocytochemistry. The distribution of NADPH‐d positive cells was centered on the laterodorsal tegmental (LDT) and pedunculopontine tegmental (PPT) nuclei. Diaphorase‐containing cells had a mean soma diameter of 23.0 ± 4.1 μm (n = 160) and were distributed inhomogeneously, with numerous cells found within densely packed clusters. A nearest‐neighbor analysis revealed that these cells were closely spaced, with up to 20% within one cell diameter and more than 50% within two cell diameters of a neighboring NADPH‐d cell. Within the LDT and PPT, NADPH‐d positive cells were mixed with smaller, diaphorase‐negative cells (diam: 12.8 ± 3.3 μm; n = 182;P< 0.01). TH‐containing cells were not organized into a compact LC as in rat and their distribution more closely resembled that observed in cat. On average, TH‐containing cells (diam: 21.2 ± 4.8 μm;n =160) were smaller than NADPH‐d cells (P< 0.01). 5‐HT‐containing cells were mainly located in the raphe nuclei, as in other species. 5‐HT‐containing cells (diam: 18.2 ± 4.4 μm; n = 161) were smaller on average than both the NADPH‐d (P< 0.01) and TH‐containing cells (P< 0.01). An analysis of the overlap in soma distributions revealed that TH‐containing cells were largely interdigitated with NADPH‐d‐containing cells. As much as 78% of the area occupied by the NADPH‐d cells of LDT was contained within the area occupied by TH cells. Substantial numbers of TH and 5‐HT immunoreactive processes were seen in both LDT and PPT. Varicose 5‐HP and TH‐containing fibers, as well as thicker, possibly dendritic processes containing TH were often seen in close apposition to NADPH‐d containing somata and proximal dendrites. These results support the hypothesis that NADPH‐d cells of both the PPT and LDT receive input from TH and 5‐HT cells. Moreover, the clustered substructure of LDT and PPT and the extensive overlap of NADPH‐d and TH‐containing somata raise the possibility that the membrane permeable messenger nitric oxide plays a role in modulating TH‐containing somata and their processes as well as 5‐HT‐containing processes in the LDT and PPT. © 1995 Wiley‐Liss Inc.
Developmental expression of glycine immunoreactivity and its colocalization with gaba in the embryonic chick lumbosacral spinal cord
Authors: Berki Ágnes Cs. , O'Donovan Michael J. , Antal Miklós
Published: January 2005

The development of immunoreactivity for the putative inhibitory amino acid neurotransmitter glycine was investigated in the embryonic and posthatched chick lumbosacral spinal cord by using postembedding immunocytochemical methods. Glycine immunoreactive perikarya were first observed at embryonic day 8 (E8) both in the dorsal and ventral gray matters. The number of immunostained neurons sharply increased by ElO and was gradually augmented further at later developmental stages. The general pattern of glycine immunoreactivity characteristic of mature animals had been achieved by E12 and was only slightly altered afterward. Most of the immunostained neurons ware located in the presumptive deep dorsal horn (laminae IV‐VI) and lamina VII, although glycine‐imrnunoreactive neurons were scattered throughout the entire extent of the spinal gray matter. By using some of our previously obtained and published data concerning the development of gamma‐aminobutyric acid (GABA)‐ergic neurons in the embryonic chick lumbosacral spinal cord, we have compared the numbers, sizes, and distribution of glycine‐ and GABA‐immunoreactive spinal neurons at various develomental stages and found the following marked differences in the developmental characteristics of these two populations of putative inhibitory interneurons. (i) GABA immunoreactivity was expressed very early (E4), whereas immunoreactivity for glycine appeared relatively late (ES) in embryonic development. (ii) In the ventral horn, GABA immunoreactivity declined, whereas immunoreactivity for glycine gradually increased from ES onward in such a manner that the sum of glycinergic and GABAergic perikarya remained constant during the second half of embryonic development. (iii) Glycinergic and GABAergic neurons showed different distribution patterns in the spinal gray matter throughout the entire course of embryogenesis as well as in the posthatched animal. When investigating the colocalization of glycine and GABA immunoreactivities, perikarya immunostained for both amino acids were revealed at all developmental stages from E8 onward, and the proportions of glycine‐ and GABA‐immunoreactive neurons that were also immunostained for the other amino acid were remarkably constant during development. The characteristic features of the development of the investigated putative inhibitory spinal interneuroris are discussed and correlated with previous neuroanatomical and physiological studies. © 1995 Wiley‐Liss Inc.
In situ hybridization analysis of vasopressin gene transcription in the paraventricular and supraoptic nuclei of the rat: Regulation by stress and glucocorticoids
Authors: Herman James P.
Published: January 2005

Hypothalamic arginine vasopressin‐containing neurons are prime elements in central circuits regulating the hypothalamo‐pituitary‐adrenocortical stress response. It is known that release and synthesis of vasopressin are cued by stressful stimuli. The present study was designed to assess effects of stress on vasopressin transcription and mRNA expression in defined populations of vasopressin neurons in the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Intron‐ and exon‐directed in situ hybridization analyses were used to examine stress regulation cf vasopressin heteronuclear (hn) gene transcription and mRNA levels. Actions of glucocorticoids on vasopressin induction were tested using adrenalectomized rats implanted with subcutaneous pellets delivering a constant, physiological dose of corticoste rone. Pellet implantation into adrenalectomized rats allows for normal pituitary‐adrenal tone in the absence of the ability to mount glucocorticoid stress responses. Elevation of vasopressin heteronuclear (hn) RNA in the medial parvicellular PVN was observed in both normal and adrenaleetomized‐corticosterone replaced rats as early as 30 minutes after stress initiation. In control rats, vasopressin hnRNA levels returned to baseline by 120 minutes. In contrast, vasopressin hnRNA remained elevated 120 minutes post‐restraint in adrenalectomized corticosterone replaced rats, indicating that the glucocorticoid stress response acts to rapidly inhibit vasopressin transcription. Significant changes in post‐stress vasopressin mRNA levels were observed in the parvicellular PVN of control rats 90 minutes following restraint induction, returning to normal expression profiles by 120 minutes. Adrenalectomized‐replaced rats showed elevated vasopressin mRNA expression at all time points examined. No changes were observed in magnocellular vasopressin‐containing nuclei at any time point, suggesting that magnocellular vasopressin is not induced by this particular stress paradigm. Thus, in parvicellular paraventricular nucleus neurons the vasopressin gene is rapidly induced by stress. Restraint‐induced up‐regulation of vasopressin transcription is limited by glucocorticoid secretion, consistent with direct actions of glucocorticoid negative feedback on the vasopressin gene in parvicellular neurons. © 1995 Wiley‐Liss, Inc.
Nerve‐mast cell interaction in normal guinea pig urinary bladder
Authors: Keith Ingegerd M. , Jin J. , Saban R.
Published: January 2005

Urinary bladders of normal adult female guinea pigs were analyzed for anatomical evidence of nerve‐mast cell interaction using light microscopy and electron microscopy. Nerves, ganglia, and individual nerve fibers were visualized on paraffin sections using immunohistochemistry with antisera against the neural antigens neurofilament protein and protein gene product 9.5, and sections were also immunoreacted with antisera against the neuropeptides substance P and calcitonin gene‐related peptide. Separate mast cell populations were identified by counterstain ing with toluidine blue and alcian blue; Mast cells of both types were found within nerves and intramural ganglia and were in close contact with individual nerve fibers displaying substance P‐ and calcitonin gene‐related peptide‐like immunoreactivity. Moreover, serotonin‐immunoreactive mast cells were innervated with nerve fibers that reacted with antiserum against vasoactive intestinal polypeptide. At the ultrastructural level, these fibers were almost exclusively identified as unmyelinated primary sensory afferents. Mast cells contacted these fibers with lamellipodia that wrapped around and enclosed the fibers deeply within the cell. Close association between mast cells, nerves, and vessels was common. Ultrastructural evidence suggests that bidirectional communication occurs between nerve fibers and mast cells. These structures may participate in axon reflexes that regulate normal vascular and detrusor smooth muscle function and cause vasodilation, edema, inflammation, and bladder hyperreactivity. In summary, a close relationship exists between mast cells and peptidergic nerve fibers, including primary sensory afferents. Results suggest that bidirectional interaction could occur between nerves and mast cells. © 1995 Wiley‐Liss, Inc.
Development of microglial topography in human retina
Authors: Diaz‐Araya Claudia M. , Provis Jan M. , Penfold Philip L. , Billson Francis A.
Published: January 2005

The development of microglial topography in wholemounts of human retina has been examined in the age range 10–25 weeks gestation (WG) using histochemistry and immunohistochemistry for CD45 and major histocompatibility complex class II antigens. Microglia were present in three planes corresponding to the developing nerve fibre layer/ganglion cell layer, the inner plexiform layer and the outer plexiform layer. Distribution patterns of cells through the retinal thickness and across the retinal surface area varied with gestational age. Microglia were elongated in superficial retina, large and ramified in the middle plane, and small, rounded and less ramified in deep retina. Intensely labeled, rounded profiles seen at the pars caeca of the ciliary processes, the retinal margin and at the optic disc may represent precursors of some retinal microglia. At 10 WG, the highest densities of microglia were present in middle and deep retina in the far periphery and at the retinal margin, with few superficial microglia evident centrally at the optic disc. At 14 WG, high densities of microglia were apparent superficially at the optic disc; microglia of middle and deep retina were distributed at more central locations although continuing to concentrate in the retinal periphery. Microglia appear to migrate into the developing human retina from two mains sources, the retinal margin and the optic disc, most likely originating from the blood vessels of the ciliary body and iris, and the retinal vasculature, respectively. The data suggest that the development of microglial topography occurs in two phases, an early phase occurring prior to vascularization, and a late phase associated with the development of the retinal vasculature. © 1995 Wiley‐Liss, Inc.
Do gonadotrophin‐releasing hormone neurons express estrogen receptors in the rainbow trout? A double immunohistochemical study
Authors: Navas José María , Anglade Isabelle , Bailhache Thierry , Pakdel Farzad , Breton Bernard , Jégo Patrick , Kah Olivier
Published: January 2005

A double immunocytochemical procedure, with two different chromogens, was used to compare the respective distributions of estrogen receptor‐immunoreactive cells and gonadotrophin‐releasing hormone‐immunoreactive neurons on the same sections of the brains of adult male and female rainbow trout (Oncorhynchus mykiss). Estrogen receptor‐immunoreactive cells were observed in the ventral and lateral telencephalon, the preoptic region, the mediobasal hypothalamus, and the ventromedial thalamic nucleus. Gonadotrophin‐releasing hormone immunoreactive perikarya were detected in the olfactory bulbs, the ventral telencephalon, the preoptic area, and the mediobasal hypothalamus. Double‐staining studies showed that, although some estrogen receptor‐positive cells were in close proximity to gonadotrophin releasing hormone‐immunoreactive perikarya, careful examination of 550 gonadotrophinreleasing hormone‐positive cells from five adult females and two adult males failed to demonstrate any evidence that gonadotrophin‐releasing hormone neurons coexpress estrogen receptor in the brain of the rainbow trout.

The present study provides, for the first time in teleosts, morphological evidence that gonadotrophin‐releasing hormone neurons do not represent major direct targets for estradiol, suggesting that the positive feedback effects of estradiol onto the gonadotrophin‐releasing hormone system are likely to be conveyed via other cell populations. © 1995 Wiley‐Liss, Inc.
Adenosine A1 receptors are located predominantly on axons in the rat hippocampal formation
Authors: Swanson Thomas H. , Drazba Judith A. , Rivkees Scott A.
Published: January 2005

The nucleoside adenosine exerts potent biological effects via specific receptors, including the inhibitory Al adenosine receptor (A1AR). In the hippocampus A1ARs play an important role in regulating neuronal activity. However, the cellular sites of hippocampal A1ARs are undefined. Using in situ hybridization, receptor autoradiography, and single‐ and double‐label immunocytochemistry techniques, we have characterized the cellular sites of A1AR expression in the rat hippocampus. In situ hybridization and receptor autoradiography studies revealed strikingly different patterns of labeling. In situ hybridization studies revealed heaviest labeling of cell bodies in the granular layer of the dentate gyrus and the pyramidal layers of Ammon's horn. In contrast, using [3H] we observed heavy specific labeling over the neuropil in the dentate hilus stratum moleculare, stratum lacunosum‐inoleculare, stratum radiatum, and stratum oriens, and little labeling over cell bodies. Using single‐label immunocytochemistry, A1AR immunoreactivity was found to be heaviest over fibers in regions corresponding with heavy [3H] labeling. Double‐label florescent confocal microscopy was then used to determine the identity of labeled fibers. A1AR immunoreactivity was found to co‐localize with SMI‐31 that labels axons, but not with MAP2a, b that labels cell bodies and dendrites, orwith synaptophysin that labels synapses. These data identify axons as the predominant site of A1AR expression in hippocampus. Activation of A1ARs may be a powerful mechanism by which adenosine alters axonal transmission to inhibit neurotransmitter release. © 1995 Wiley‐Liss, Inc.
Neurochemical subdivisions of the inferior pulvinar in macaque monkeys
Authors: Gutierrez C. , Yaun A. , Cusick C. G.
Published: January 2005

The architecture of the pulvinar of rhesus monkeys was investigated by acetylcholinester ase (AChE) histochemistry, and by immunocytochemiatry for calbindin‐D28k and the SMI‐32 antibody. The presence of four inferior subdivisions, comparable to those found in architectonic connectional studies in squirrel monkeys (C. G. Cusick, J Scripter, J. G. Darensbourg, and J. T. Weber, 1993, J. Comp. Neurol. 336:1–30), provided a basis for a proposed revised terminology for visual sectors of the macaque pulvinar. In the present study, the inferior pulvinar (PI) was identified as a neurochemically distinct region that included the traditional cytoarchitectonic nucleus PI and adjacent portions of the lateral and medial pulvmar nuclei, PL and PM. In calbindin‐D28k stains, the lateral. subdivision of the inferior pulvinar (PIL) had less intense neuropil staining than the adjacent central division, PIc. The PIL was characterized by large, intensely immunopositive neurons seldom found within Plc. PIL occupied the traditional PL and PI and exhibited a shell zone, PIL‐S, restricted to PL. The medial division of the inferior pulvinar (PIM) was in a location previously shown to be strongly connected with the middle temporal visual area (MT) in macaques. PIM was found in the medial one‐half of the traditional PI and extended into adjacent portions of the traditional PM and PL. PIM was distinguished by less intense staining for calbindin and many cells stained with the SMI‐32 antibody for neurofilament protein. In AChE stains, PIL was moderately dark, Plc appeared lighter, and PIM was characterized by small, intensely stained patches. The small posterior division (PIP) stained darkly for calbindin, lightly for AChE, and was unstained with the SMI‐32 antibody. Thus, neurochemical, and perhaps connectional, subdivisions exist within PI, the region of the pulvinar that relays information to striate, “lower order” extrastriate, and inferotemporal visual cortex. © 1995 Wiley‐Liss, Inc.
Limbic connections of the orbital and medial prefrontal cortex in macaque monkeys
Authors: Carmichael S. T. , Price J. L.
Published: January 2005

Previous studies have shown that the orbital and medial prefrontal cortex (OMPFC) is extensively connected with medial temporal and cingulate limbic structures. In this study, the organization of these projections was defined in relation to architectonic areas within the OMPFC. All of the limbic structures were substantially connected with the following posterior and medial orbital areas: the posteromedial, medial, intermediate, and lateral agranular insular areas (Iapm, Iam, Iai, and Ial, respectively) and areas 11m, 13a, 13b, 14c, and 14r. In contrast, lateral orbital areas 12o, 12m, and [12] and medial wall areas 24a, b and 32 were primarily connected with the amygdala, the temporal pole, and the cingulate cortex. Data were not obtained on the poateroventral medial wall.

Three distinct projections were recognized from the basal amygdaloid nucleus: (1) The dorsal part projected to area 121; (2) the ventromedial part projected to most areas in the posterior and medial orbital cortex except for areas Iai, 12o, 13a, and 14c; and (3) the ventrolateral part projected to orbital areas 12o, Iai, 13a, 14c, and to the medial wall areas. The accessory basal and lateral amygdaloid nuclei projected most strongly to areas in the posterior and medial orbital cortex. The medial, anterior cortical, and central amygdaloid nuclei and the periamygdaloid cortex were connected with the posterior orbital areas.

The projection from the hippocampus originated from the rostral subiculum and terminated in the medial orbital areas. The same region was reciprocally connected with the anterornedial nucleus of the thalamus, which received input from the rostral subiculum. The parahippocampal cortical areas (including the temporal polar, entorhinal, perirhinal, and posterior parahippocampal cortices) were primarily connected with posterior and medial orbital areas, with some projections to the dorsal parr of the medial wall. The rostral cingulate cortex sent fibers to the medial wall, to the medial orbital areas, and to lateral areas 12o, 12r, and Iai. The posterior cingulate gyrus, including the caudomedial lobule, was especially strongly connected with area 11 m. © 1995 Wiley‐Liss, Inc.
Alpha adrenergic receptors and gastric function
Authors: Taylor John A. , Mir G. Nabi
Published: January 2005

Alpha‐2 agonists by an effect on alpha‐2 adrenoreceptors in the stomach (and probably in the brain also) suppress vagal nerve acetylcholine release thereby inhibiting gastric motility and secretion and inhibiting the development of gastric lesions in rats in the stress‐, reserpine‐, and cysteamine‐induced ulcer models. Since the effects of the alpha‐2 agonists are consistently inhibited by alpha‐2 blocking agents, their effects appear to be selectively mediated via the alpha‐2 receptor. It seems appropriate therefore that the role of the alpha‐2 receptors be recognized in studies of gastric function and ulcer development.
Central sympathomimetic activity of (+)‐5‐methyl‐10,11‐dihydro‐5H‐dibenzo [a, d]cyclohepten‐5,10‐imine (MK‐801), a substance with potent anticonvulsant, central sympathomimetic, and apparent anxiolytic properties
Authors: Clineschmidt Bradley V. , Martin Gregory E. , Bunting Patricia R. , Papp Nan L.
Published: January 2005

MK‐801 at doses < 100 μg/kg given orally induced an ipsilaterally directed directed rotational response in rats with a unilateral nigrostriatal lesion produced by 6‐hydroxydopamine. (+)‐Amphetamine, amfonelic acid, and methylphenidate also evoked ipsilateral turning with their dose‐response lines lying considerably to the right of that for MK‐801. Rotations caused by a standard test dose of 50 μg/kg of MK‐801 were reduced by pretreatment with haloperidol (ED50 = 0.068 mg/kg IP), clozapine (ED50 = 3.35 mg/kg IP), or prazosin (ED50 = 0.15 mg/kg SC). MK‐801‐induced turning was also inhibited by pretreatment with α‐methyl‐p‐tyrosine (α‐MPT) and blocked by reserpine.

Locomotor activity in mice was increased by MK‐801, amfonelic acid, (+)‐amphetamine, and methylphenidate. Following administration p.o., MK‐801 was the most potent in this regard and methylphenidate the least. Stimulation of locomotor activity by equivalent doses of the four compounds was differentially affected by pretreatment with α‐MPT or reserpine, Reserpinization abolished the increase in activity usually produced by MK‐801, amfonelic acid and methylphenidate, whereas (+)‐amphetamine was only partially (36%) inhibited. Locomotor stimulation by (+)‐amphetamine was, on the other hand, markedly reduced in α‐MPT‐pretreated mice, while the actions of the other three compounds were not singnificantly altered. The ability of all four compounds to increase motor activity was significantly antagonized by haloperidol, but prazosin at the dose (3 mg/kg SC) examined was an effective antagonist of only MK‐801 and (+)‐amphetamine.

MK‐801 has effects in rodents resembling indirect‐acting central sympathomimetic substances such as amfonelic acid, (+)‐amphetamine, and methylphenidate. The central sympathomimetic actions of MK‐801 are mediated via catecholamine‐dependent processes. Results from the drug‐interaction studies in mice (locomotor activity) indicate that the precise mechanism of action of MK‐801 differs from that of the other three compounds.
Antiserotoninergic properties of maprotiline and a new antidepressant, oxaprotiline: Two selective na uptake inhibitors
Authors: Delini‐Stula A. , Bischoff S. , Radeke E.
Published: January 2005

Antiserotoninergic effects of maprotiline and its hydroxy derivative oxaprotiline (Ba 49802 B), two selective inhibitors of NA uptake, and clinically active antidepressants were investigated in several functional tests and also in in vivo 3H‐spiperone binding assay in the rat. In some tests comparisons with amitriptyline, mianserin, and fluoxetine, which are antidepressants of different qualities, were also done. After single doses up to 30 mg/kg neither maprotiline nor oxaprotiline inhibited L‐5‐HTP‐induced head twitch in mice or tryptamineinduced paw clonus in the rat. Maprotiline, however, but not oxaprotiline, significantly reduced the hyperthermic response to LSD in rabbits and blocked to nearly 90% the 3H‐spiperone labeled 5‐HT receptors in the rat frontal cortex at a dose of 30 mg/kg. Moreover, maprotiline also reduced the response of mice to L‐5‐HTP after daily administration of 25 mg/kg over 10 days. No change in the responsiveness of mice to L‐5‐HTP was observed after the same treatment with oxaprotiline. In agreement with other observations, mianserin and amitryptiline displayed clear‐cut antiserotoninergic effects, whereas fluoxetine potentiated the effects of tryptamine and LSD. The results of this study indicate that, although chemically closely related, maprotiline and oxaprotiline distinctly differ in respect to their action on 5‐HT receptors. Maprotiline exerts 5‐HT receptor blocking effects that appear to increase upon repetitive administration in mice. Oxaprotiline, by contrast, is devoid of them. Comparative experimental and clinical investigations of maprotiline and oxaprotiline may, therefore, provide a clue as to the importance of 5‐HT receptor blocking properties for antidepressant profile of action of drugs.
The antiulcer and antisecretory activity of WHR‐1370A 1‐n‐butoxy‐3‐(2,6 dimethylphenylcarbamoyl) guanidine hydrochloride
Authors: Taylor J. A. , Eash J. R. , Nabi Mir G.
Published: January 2005

WHR‐1370A in the rat reduces volume (ED50 = 1.3 mg/kg p.o.) acidity (1.8 p.o.), and pepsin (2.8 p.o.) in the 4‐hr pylorus ligation model, delays gastric emptying (0.75 p.o.), and protects against the development of stress (18‐hr restraint)‐, indomethanic‐, aspirin‐, reserpine‐, and cysteamine‐induced ulcers (ED50s: 10.0 s.c., .65 p.o., 0.59 p.o., 3.0 p.o., and 8.0 s.c., respectively); also WHR‐1370A can completely suppress the cysteamine‐induced rise in serum gastrin. In the pylorus‐ligated rat, the activity of WHR‐1370A is not appreciably altered by methysergide, pimozide, propranolol, corynanthine, or phentolamine but is significantly and competitively antagonized by yohimbine. The pharmacological basis of WHR‐1370A probably can be attributed to an alpha‐2‐mediated inhibition of acetylcholine release at vagal nerve endings.
Central GABA‐ergic systems and analgesia
Authors: Defeudis F. V.
Published: January 2005

Recent studies regarding the relationship between GABA‐ergic systems and analgesia have been reviewed and analyzed. It seems evident that central GABA‐ergic systems are involved in opiate‐mediated analgesia since oral or parenteral administration of agents that elicit increases in GABA content of the CNS can enhance the actions of opiates (e.g., morphine). Also, oral or parenteral administration of GABA‐agonists (e.g., 4,5,6,7‐tetrahydroisoxazolo[5,4‐c]‐pyridin‐3‐ol; THIP), inhibitors of GABA‐α‐oxoglutarate transaminase (e.g., γ‐vinyl‐GABA), or GABA uptake inhibitors (e.g., nipecotic acid ethyl ester) can produce analgesia. As the analgesia produced by agents that enhance central GABA‐ergic mechanisms is not reversed by naloxone, its further study might lead to the development of centrally active analgesic drugs that do not produce physical dependence/tolerance in man.