bluuebunny/crossref_metadata_2025 huggingface dataset:
Giant terminals in the dorsal octavolateralis nucleus of lampreys
Authors: Koyama Hiromichi , Kishida Reiji , Goris Richard , Kusunoki Toyokazu
Published: January 2005

The dorsal octavolateralis nucleus of lampreys is a primary nucleus for electroreceptive stimuli in the medulla. In Lampetra japonica, the rostral and caudal thirds of this nucleus are exclusively occupied by giant terminals, which become evident when the primary fibers of an electrosensory nerve (recurrent branch of the anterior lateral line nerve) are labeled with horseradish peroxidase. We studied the ultrastructure of these terminals. They contain neurofilaments, mitochondria, microtubules, and tubular membranous structures. Many synapses, all of the chemical type, are located around the neck region of the terminal swellings. Many vesicular structures, which are clear, round, and uniform in size, and most of which are probably synaptic vesicles, are densely clustered in a single large mass in the neck region of the terminals. Some of the tubular structures may serve as a membrane reservoir for the large number of synaptic vesicles required in the giant terminals. © 1993 Wiley‐Liss, Inc.
Coexistence of NADPH diaphorase with GABA, glycine, and acetylcholine in rat spinal cord
Authors: Spike Rosemary C. , Todd Andrew J. , Johnston Heather M.
Published: January 2005

The enzyme NADPH diaphorase is present in many spinal neurons, and is thought to correspond to nitric oxide synthase. In order to determine which types of neuron in the spinal cord contain this enzyme, we have carried out a combined enzyme histochemical and immunocytochemical study with antibodies to GABA, glycine, and choline acetyltransferase. Two hundred and twenty‐four NADPH diaphorase‐positive neurons in midlumbar spinal cord from four rats were tested for GABA‐ and glycine‐like immunoreactivity. The majority of these neurons (207/224) were GABA‐immunoreactive and 139 were also glycine‐immunoreactive. NADPH diaphorase‐positive neurons in laminae I and II generally showed both types of immunoreactivity, while those in deeper laminae of the dorsal horn and around the central canal either showed both types or else were only GABA‐immunoreactive. Since GABA and acetylcholine are thought to coexist in spinal neurons, NADPH diaphorase staining was combined with immunostaining for choline acetyltransferase. Immunoreactive neurons in laminae III and IV were all NADPH diaphorase‐positive, while only some of those around the central canal and in the deeper laminae of the dorsal horn were positive. Choline acetyltransferase‐immunoreactive neurons in the intermediolateral cell column (presumed sympathetic preganglionic neurons) were often NADPH diaphorase‐positive, whereas those in the ventral horn (presumed motorneurons) were not. NADPH diaphorase‐positive cells in the intermediolateral cell column were not immunoreactive with GABA or glycine antibodies.

These results suggest that NADPH diaphorase is largely restricted to GABAergic neurons in the lumbar spinal cord, and that it is mainly present in those neurons in which GABA coexists with glycine or acetylcholine. Since nitric oxide has been implicated in pain processing and hyperalgesia, while GABA, glycine, and acetylcholine are thought to be involved in analgesia and prevention of hyperalgesia, it is likely that nitric oxide synthase‐containing GABAergic neurons in dorsal horn have dual actions in transmission of nociceptive information. © 1993 Wiley‐Liss, Inc.
Monoclonal antibody labels olfactory and visual pathways in Drosophila and Apis brains
Authors: Bicker Gerd , Kreissl Sabine , Hofbauer Alois
Published: January 2005

We employed a monoclonal antibody raised against Drosophila brain homogenate for a comparative immunocytochemical analysis of visual and olfactory pathways in brains of two insect species. On Western blots of Drosophila and Apis nervous tissue, antibody fb45 recognized an antigen with an apparent molecular weight higher than 180 kD. Application of the antibody to sections of Drosophila and Apis brain stained certain interneurons which conspicuously fasciculate in common tracts or neuropilar compartments. Both in Drosophila and in Apis, the antigen was also expressed on the perineural sheath and granular cell compartments in the majority of neuronal cell bodies.

The antibody stained monopolar cells in the visual system of both species, and in Apis those fibers of the anterior superior optic tract which link the medulla with the mushroom bodies. In Drosophila, bundles of Kenyon cells of the mushroom bodies were stained. In worker bees and drones, the relay neurons of the median and lateral antennoglomerular tracts were labelled.

Since the recognition of the antigen does not require fixation, the antibody can be employed to label selectively living neurons in dissociated cell culture. This opens up the possibility for future functional studies on the role of the antigen in vitro. © 1993 Wiley‐Liss, Inc.
Cholinergic innervation of the amygdaloid complex in the human brain and its alterations in old age and Alzheimer's disease
Authors: Emre Murat , Heckers Stephan , Mash Deborah C. , Geula Changiz , Mesulam M.‐Marsel
Published: January 2005

The cholinergic innervation of the human amygdaloid complex was studied immunohistochemically with a choline acetyltransferase (ChAT) antibody in eight brains: five control and three with Alzheimer's disease (AD). All amygdaloid nuclei displayed ChAT‐immunopositive axons and varicosities. The density of these axons reached levels that were higher than in any other part of the forebrain except for the striatum. The highest level of ChAT‐immunopositive profiles was seen in the basolateral nucleus and the second highest in the lateral part of the central nucleus. The basomedial, accessory basal, and cortical nuclei, the amygdalohippocampal and cortico‐amygdaloid transition areas, as well as the anterior amygdaloid area, showed a moderate density of ChAT‐positive varicosities and fibers. The lateral nucleus displayed a relatively low density of cholinergic innervation, and there were only rare ChAT‐positive fibers in the medial nucleus. Although the level of cholinergic innervation in the lateral nucleus was relatively lower than in many of the other amygdaloid nuclei, it was approximately equivalent to that of entorhinal cortex, a region that receives one of the heaviest cholinergic inputs in the cerebral cortex. The distribution of the cholinergic fibers as studied by ChAT immunohistochemistry was nearly identical to that observed with AChE histochemistry. Quantitative densitometry in control specimens showed that there was no decline of amygdaloid cholinergic input when middle‐aged subjects were compared with senescent subjects. In AD there was a severe and regionally selective depletion of this innervation in the amygdaloid complex. The cortical, accessory basal, and lateral nuclei displayed the most severe loss of ChAT‐positive profiles, whereas the basolateral, and especially the central, nuclei displayed relatively little change. There was no consistent relationship between the loss of cholinergic fibers and the density of amyloid plaques and neurofibrillary tangles in amygdaloid nuclei. © 1993 Wiley‐Liss, Inc.
Connections of the auditory forebrain in the pigeon (columba livia)
Authors: Martin Wild J. , Karten H. J. , Frost B. J.
Published: January 2005

Ascending auditory efferents in birds terminate mainly within Field L2, a cytoarchitectonically distinct region of the caudomedial telencephalon. The organization of Field L2, and that of its flanking regions, L1 and L3, was investigated with 14C‐2‐deoxyglucose (14C‐2‐DG), cytochrome oxidase, and both retrograde and anterograde tracing techniques.

Field L2 was found to contain a high concentration of cytochrome oxidase. Following auditory stimulation, 14C‐2‐DG autoradiography revealed that Field L2 consists of two adjacent but seemingly discontinuous zones, designated Field L2a, which lies ventromedially, and Field L2b, which lies dorsolaterally.

Termination of thalamic efferents: The thalamic auditory nuclei ovoidalis (Ov) and semilunaris parovoidalis (SPO) project predominantly upon Field L2, and possibly sparsely upon L1, L3 and the overlying hyperstriatum ventrale (HV). Ov subnuclei project upon L2a and SPO projects predominantly upon L2b. The topography of the projections is inverted along the ventromedial‐to‐dorsolateral axis of L2, and is in accord with an inverted tonotopic representation of frequencies; high frequencies (<3.5 kHz) being found in the more ventromedial parts of L2a, and low frequencies and broad band responses in L2b.

Intra‐ and extratelencephalic connections: Field L2a also receives a substantial projection from HV, but the efferent projections of L2a appear confined to adjacent “neostriatal” regions. The subsequent projections of L2b were not identified in this study. L1 and L3 project predominantly to the dorsal neostriatum (Nd) caudolateral to Field L, and have fewer projections to the caudomedial paleostriatum and anterior hyperstriatum accessorium. Nd projects massively upon the ventromedial nucleus of the intermediate archistriatum (Aivm), which has bilateral projections upon the caudomedial telencephalon and is the origin of a major descending pathway having dense terminations surrounding the ovoidalis complex (Ov and SPO), MLd, the lateral lemniscal nuclei, and sparse terminations within SPO itself.

It is suggested that within the telencephalon the major components of the auditory pathway consist of cell groups which collectively correspond to the populations of neurons found within the auditory cortex of mammals. © 1993 Wiley‐Liss, Inc.
Projections from the nucleus tractus solitarii to the spinal cord
Authors: Mtui Estomih P. , Anwar Muhammad , Gomez Roberto , Reis Donald J. , Ruggiero David A.
Published: January 2005

Projections from the nucleus tractus solitarii (NTS) to the spinal cord were demonstrated in the male Sprague‐Dawley rat. In retrograde transport studies, a horseradish peroxidase conjugate or a fluorescent dye, Fluoro Gold, were injected into midcervical or upper thoracic spinal segments. Most solitariospinal neurons were multipolar or bipolar and located between the obex and spinomedullary junction. Solitariospinal neurons were concentrated in proximity to the ventral border of the solitary tract and extended dorsally into the intermediate division and ventrolaterally into the intermediate reticular zone (IRt) of the lateral tegmental field. This subgroup predominantly projects to midcervical spinal segments. A subset of small neurons was retrogradely labeled from cervical or thoracic spinal segments in the medial commissural nucleus and contiguous with a periventricular group surrounding the central canal.

In anterograde transport studies, iontophoretic deposits of Phaseolus vulgaris leucoagglutinin were centered stereotaxically on sites in NTS identified by retrograde transport data. The lectin was incorporated by neurons of the solitary complex and transported bilaterally by axons that emerged from the nucleus and entered the reticular formation. The solitario‐reticular (transtegmental) pathway irradiated diagonally across the IRt and extended caudally into the cervical lateral funiculus and spinal gray. A small periventricular‐spinal pathway also descended longitudinally to the neuraxis. Solitariospinal neurons project to superficial lamina of the dorsal horn, laminae VII and X and ventral horn. The projections are predominantly contralateral to phrenic and intercostal motor nuclei and ipsilateral to the intermediolateral cell column. The solitariospinal projection represents the shortest route in the central nervous system, other than the local intraspinal reflex, through which first order visceral afferents signal cardiorespiratory and alimentary motor nuclei. © 1993 Wiley‐Liss, Inc.
SmI cortical barrels in an australian marsupial, Trichosurus vulpecula (brush‐tailed possum): Structural organization, patterned distribution, and somatotopic relationships
Authors: Weller W. Lee
Published: January 2005

This study reports on the cerebral cortex of an Australian marsupial, Trichosurus vulpecula (brush‐tailed possum). It consists of an analysis of layer IV of somatosensory cortex in tangential sections of flattened specimens and in oblique radial sections stained to show Nissl substance or myelin, or tested for succinic dehydrogenase. It includes results of electrophysiological mapping experiments that ascertained the somatotopic significance of the cytoarchitecture of this cortical region.

Layer IV has two interlocking cytoarchitectural fields: one granular (the barrelfield, comprising cell‐dense barrels 150 to 500 μm in diameter) and one dysgranular. Only neurons within the granular field responded to light cutaneous stimulation. In the barrelfield cell‐sparse septa (about 100 μm wide), low in succinic dehydrogenase activity and containing many radial myelinated axons, separate adjoining barrels. Possum barrels are “solid,” lacking the prominent hollows characteristic of most rodent barrels. In some specimens three to five small neuronal “lobules” may constitute each large barrel.

In tangential sections the size, shape, and arrangement of barrels combine to form a histological caricature of the possum's body, especially of the face and forepaw. Six rows of “mystacial barrels” are homeomorphic to the six rows of large mystacial vibrissae, and “forepaw barrels” are homeomorphic to the glabrous palmar and apical digital pads. Correlating cortical recording sites and receptive fields confirmed that individual barrels represent specific cutaneous regions.

These results show that the cortical barrels of brush‐tailed possums are remarkably similar to those of rodents, in structure, arrangement, and functional significance. © 1993 Wiley‐Liss, Inc.
Physiology and morphology of spiking local interneurons in the terminal abdominal ganglion of the crayfish
Authors: Nagayama Toshiki , Isogai Yukihiro , Namba Hisaaki
Published: January 2005

Not only nonspiking local interneurons but also spiking local interneurons in the terminal abdominal ganglion of the crayfish (Procambarus clarkii Girard) contribute to form the motor output of the uropod. In this study, 14 spiking local interneurons are identified by their gross morphology and physiological properties including the sensory inputs from the uropod and premotor output onto the uropod motor neurons on both sides. Morphologically, they are divided into three groups based on the position of their somata: anterior, medial, and posterior. The main branches of interneurons in each group are usually extended on the side contralateral to the soma, or they have profuse bilateral branches. Physiologically, all of them receive excitatory inputs from the afferents innervating the exopodite on the side ipsilateral their main branches. They are usually silent, and spike only in response to sensory stimulation. The majority of them (11 out of 14 neurons) have output effects on the uropod motor neurons that elicit reciprocally closing pattern. They increased the activity of the closer motor neurons and decreased the activity of the opener motor neurons. Only one interneuron inhibits the closer motor neurons. The remaining two interneurons coactivate both the antagonistic motor neurons. Since the reciprocal closing pattern of the uropod motor neurons is elicited in response to sensory stimulation of the uropod, spiking local interneurons may initiate this local reflex circuit. They detect the initiation of the stimulus and convey signals from the sensory to the motor side. © 1993 Wiley‐Liss,Inc.
Stathmin: Cellular localization of a major phosphoprotein in the adult rat and human CNS
Authors: Peschanski Marc , Hirsch Etienne , Dusart Isabelle , Doye Valérie , Marty Serge , Manceau Valérie , Sobel André
Published: January 2005

Stathmin is a ubiquitous, 19 kDa cytoplasmic protein the phosphorylation of which is associated with many cellular signaling pathways. It is particularly abundant in neurons and reaches a peak of expression in the neonatal period, although it remains highly expressed in the adult brain. In order to determine whether this abundant expression is associated with discrete cellular populations that are still at an immature stage during adulthood, as suggested by others, the cellular localization of stathmin was investigated in the adult rat and human central nervous system.

Western blotting with a specific antiserum indicated that stathmin was unbiquitous in the brain and spinal cord but that its relative concentration varied up to 2.6 times between regions. To characterize the distribution of stathmin within the brain, its cellular localization was analyzed by immunocytochemistry. Highly immunoreactive neurons and oligodendrocytes were observed, and stathmin immunoreactivity was localized to the perikaryon and all processes, but not the nucleus. Most brain and spinal cord cell groups showed stathmin immunoreactivity, although the extent and intensity of labeling differed largely from one place to another. Particularly numerous stathmin‐immunoreactive neuronal cell bodies were found in the pyriform, cingulate, and neocortex, as well as in many cholinergic nuclei of the basal forebrain and brainstem, in the medial thalamus, in various brainstem nuclei, in the dorsalmost layers of the spinal cord, and in brain areas lacking a blood‐brain barrier to macromolecules. In addition to neuronal populations, stathmin‐antibodies intensely labeled choroid plexuses. Many other brain regions exhibited moderate neuronal immunostaining. The distribution of stathmin‐immunoreactive processes was in some areas relatively heterogeneous. Intense immunoreactivity was observed in some fiber tracts (corpus callosum, anterior commissure, inferior cerebellar peduncle, etc.) but was missing in others (internal capsule, posterior commissure, etc.). Some brain areas rich in immunoreactive neurons also displayed an intense immunoreactivity of the neuropile, whereas others contained either immunoreactive cells or fibers. In the human brain, stathmin immunostaining occurred in many areas, corresponding to those identified in the rat, with the exception of the cerebral cortex, the hippocampal fascia dentata, and the substantia nigra.

The present results support our suggestion that, in addition to its involvement in cell proliferation and differentiation, stathmin may also be related to regulation of differentiated cell functions, as it appears to be a major signaling protein in widespread areas of the adult brain in both rat and human. © 1993 Wiley‐Liss,Inc.
Corticocortical connections of area F3 (SMA‐proper) and area F6 (pre‐SMA) in the macaque monkey
Authors: Luppino Giuseppe , Matelli Massimo , Camarda Rosolino , Rizzolatti Giacomo
Published: January 2005

The monkey mesial area 6 comprises two distinct cytoarchitectonic areas: F3 [supplementary motor area properly defined (SMA‐proper)], located caudally, and F6 (pre‐SMA), located rostrally. The aim of the present study was to describe the corticocortical connections of these two areas. To this purpose restricted injections of neuronal tracers (wheat germ‐agglutinin conjugated to horseradish peroxidase, fluorescent tracers) were made in different somatotopic fields of F3, F6, and F1 (area 4) and their transport plotted.

The results showed that F3 and F6 differ markedly in their cortical connections. F3 is richly linked with F1 and the posterior premotor and cingulate areas (F2, F4, 24d). Connections with the anterior premotor and cingulate areas (F6, F7, F5, 24c) although present, are relatively modest. There is no input from the prefrontal lobe. F3 is also connected with several postrolandic cortical areas. These connections are with areas PC, PE, and PEa in the superior parietal lobule, cingulate areas 23 and PEci, the opercular parietal areas (PFop, PGop, SII) and the granular insula.

F6 receives a rich input from the anterior premotor areas (especially F5) and cingulate area 24c, whereas its input from the posterior premotor and cingulate areas is very weak. A strong input originates from area 46. There are no connections with F1. The connections with the postrolandic areas are extremely meagre. They are with areas PG and PFG in the inferior parietal lobule, the disgranular insula, and the superior temporal sulcus.

A further result was the demonstration of a differential connectivity pattern of the cingulate areas 24d and 24c. Area 24d is strongly linked with F1 and F3, whereas area 24c is connected mostly with F6.

The present data support the notion that the classical SMA comprises two functionally distinct areas. They suggest that F6 (the rostral area) is responsible for the “SMA” so‐called high level motor functions, whereas F3 (the caudal area) is more closely related to movement execution. © 1993 Wiley‐Liss, Inc.
Organization of the proximal, orbital segment of the infraorbital nerve at multiple intervals after axotomy at birth: A quantitative electron microscopic study in rat
Authors: Golden Judith P. , Rana Jamil Z. , Davis Jason , Zahm Daniel S. , Jacquin Mark F.
Published: January 2005

Although much is known of the central consequences of infraorbital nerve (ION) transection at birth, little is known about the effects of this lesion on the organization of the ION itself. To advance our understanding of how deafferentation alters the developing trigeminal neuraxis, 19 newborn rats were subjected to left ION section and perfused 1, 2, 4, 7, 17, or 90 days later. Left IONs were removed in the orbit proximal to the nerve injury site, and axon numbers, types, and fasciculation patterns were assessed with light and electron microscopic methods. Complete axon counts demonstrated that the axotomized ION contained an average (±SD) of 13,945 ± 10,335, 14,112 ± 3,501, 16,531 ± 1,904, 9,045 ± 1,465, 7,018 ± 4,212, and 8,672 ± 1,030 axons at the above‐listed ages, respectively. These values are well below the 33,059 axons in the normal adult ION (Jacquin et al. [1984] Brain Res. 290:131–135) and the 42,219 axons in the newborn ION (Renehan and Rhoades [1984] Brain Res. 322:369–373). The axotomized ION also contained lower than normal percentages of myelinated axons (26.7% ± 6.3% on postnatal day 90 vs. 59.7% ± 6.2% in normal adults). Unmyelinated fibers constituted the vast majority of the remaining fiber types; degenerating fibers never accounted for > 1.6% of all the axons. The number of fascicles making up the axotomized ION overlapped significantly with those found in the normal newborn and adult ION.

We conclude that (1) extensive, though variable, axon elimination occurs proximally within one day of the lesion; (2) the 74% reduction in fiber number seen at 90 days is not reliably achieved until postnatal day 7;(3) the higher than normal proportion of unmyelinated axons in the injured ION may underly many of the known effects of neonatal ION injury on the developing whisker‐barrel neuraxis; (4) gross changes in ION fasciculation patterns are not prerequisite to injury‐induced pattern alterations in the developing trigeminal system. © 1993 Wiley‐Liss, Inc.
Nucleus of the solitary tract and dorsal motor nucleus of the vagus nerve of the pigeon: Localization of peptide and 5‐hydroxytryptamine immunoreactive fibers
Authors: Berk Mitchell L. , Smith Stacy E. , Karten Harvey J.
Published: January 2005

The distribution of peptide and serotonin fibers in the nucleus of the solitary tract (NTS) and the dorsal motor nucleus of the vagus nerve (DMNX) in the pigeon (Columba livia) was investigated immunocytochemically. This information was correlated with the viscerotopic organization of the nuclei and with central NTS circuitry to suggest the role of the neurochemical containing fibers in the regulation of organ function. The distribution of fibers containing cholecystokinin (CCK), calcitonin gene‐related peptide (CGRP), enkephalin (ENK), neuropeptide Y (NPY), neurotensin (NT), substance P (SP), somatostatin (SS), vasoactive intestinal peptide (VIP), and 5‐hydroxytryptamine (5‐HT) was determined. Each substance had a distinct distribution within the subnuclei of NTS‐DMNX, but certain generalities can be deduced. In the DMNX, fibers immunoreactive for ENK, NT, and SP were found in greatest concentration, while CGRP and 5‐HT immunoreactive fibers were the least dense. This suggests that ENK, NT, and SP may have a significant modulatory effect on gastrointestinal functions. In the NTS overall, ENK, NT, SP, and VIP fibers were found in high density, CCK, NPY, SS, and 5‐HT fibers were found in moderate density, and CGRP fibers were found in low density. However, some individual NTS subnuclei were found to contain moderate to high concentrations of each of the substances, including CGRP. Fibers containing CCK, ENK, NT, SP, SS, and VIP in the medial dorsal NTS subnuclei may regulate gastroesophageal functions. The caudal part of subnucleus lateralis parasolitarius did not contain most of the substances, which suggests that pulmonary function is not modulated by these neurochemicals. The boundaries of a subnucleus could sometimes be demarcated by a change in density of immunoreactive fibers between adjacent subnuclei. This was particularly evident in NTS subnuclei medialis dorsalis anterior centralis and lateralis parasolitarius, and in DMNX subnucleus posterior dorsalis magnocellularis. The selective distribution of peptide and serotonin immunoreactive fibers in various subnuclei of NTS‐DMNX suggests that these substances may be differentially involved in neural circuits that mediate cardiovascular and gastrointestinal functions. © 1993 Wiley‐Liss, Inc.
Development of the thalamic reticular and perireticular nuclei in rats and their relationship to the course of growing corticofugal and corticopetal axons
Authors: Mitrofanis John , Baker Gary E.
Published: January 2005

This study examines the connections of the thalamic reticular and perireticular nuclei during development. In addition, because these nuclei lie directly in the path of corticofugal and corticopetal axons during development, we have examined the relationship of these growing axons to the reticular and perireticular cell groups. Neurones were labelled by applying DiI, wheat germ agglutinin conjugated to horseradish peroxidase (WGA‐HRP), or HRP to the dorsal thalamus and/or cerebral cortex of rats at different stages of development.

The axons of neurones in the reticular nucleus reach the dorsal thalamus as early as embryonic day (E) 14. At this age, and during later prenatal development, a small DiI implant limited to the presumptive lateral geniculate nucleus labels reticulothalamic and thalamocortical axons which travel in a clearly defined bundle through the thalamus.

During late gestation, thalamocortical (∼ E15) and corticothalamic (∼ E17) axons pass directly through the reticular nucleus toward their targets. It is not until birth that collaterals are seen extending into the nucleus from the parent axons.

Neurones in the perireticular nucleus, in contrast to those in the reticular nucleus, are not labelled from the lateral geniculate nucleus until after birth. The perireticular nucleus is very large at a stage when the first thalamocortical axons leave and when the first corticothalamic axons approach the thalamus. These axons are seen to change course sharply in the region of the internal capsule, where there are many perireticular cells. Corticothalamic axons turn toward the reticular nucleus, and thalamocortical axons turn toward the cortical subplate. Corticospinal and corticobulbar axons, on the other hand, pass directly through the perireticular region toward their more caudal targets. After these axons have reached their targets, the perireticular nucleus reduces dramatically in size. © 1993 Wiley‐Liss, Inc.
Postnatal development of different classes of cat retinal ganglion cells
Authors: Ault Steven J. , Leventhal Audie G.
Published: January 2005

Previous investigators have documented the postnatal development of alpha and beta type ganglion cells in cat retinae (Ramoa et al. [1987] Science 237:522–525; Ramoa et al. [1988] J. Neurosci. 8:4239–4261; Dann et al. [1987] Neurosci. Lett. 80:21–26; Dann et al. [1988] J. Neurosci. 8(5):1485–1499). The development of the remaining cells (about 50%), which constitute a heterogeneous group and are referred to here collectively as gamma cells (Boycott and Wässle, '74), has not been studied in detail. The purpose of this study was to compare the postnatal development of alpha, beta, and gamma cells in kitten and adult retinae using horseradish peroxidase histochemistry and the fluorescent dye Dil. In the kitten, alpha, beta, and gamma cells are recognizable. We find, as have others, that kitten alpha and beta cell bodies and dendritic fields are significantly smaller than in the adult. However, kitten gamma cells are nearly adult sized. In fact, at birth the cell bodies of beta cells throughout the retina are significantly smaller than those of gamma cells. During the first 12 weeks of life, alpha and beta cell bodies increase in size from 90% to 680% depending upon eccentricity. Gamma cells hardly increase in size at all. Also, the normal adult center‐to‐peripheral cell size gradient for alpha and beta cells is not seen in the neonate. Gamma cells show no such gradient in the neonate or adult. Our results suggest that the morphological development of alpha and beta cells occurs later than that of gamma cells and may explain some of the differences in the effects of visual deprivation and surgical manipulation upon the parallel Y‐, X‐, and W‐cell pathways. © 1994 Wiley‐Liss, Inc.
Postembryonic development of γ‐aminobutyric acid‐like Immunoreactivity in the brain of the sphinx moth Manduca sexta
Authors: Homberg Uwe , Hildebrand John G.
Published: January 2005

We have investigated the distribution of immunocytochemical staining for the neurotransmitter γ‐aminobutyric acid (GABA) in the brain of the sphinx moth Manduca sexta during larval, pupal, and adult development. In the larval brain, about 300 neurons are GABA‐immunoreactive. All neuropil areas except the mushroom bodies and central complex show intense immunostaining. Only minor changes in the pattern of immunoreactivity occur during larval development. During metamorphosis, changes in immunostaining occur in two phases. Beginning in wandering fifth‐instar larvae (stage W2), immunoreactivity appears in numerous neurons of the central body and optic lobe and becomes more intense during early pupal stages. At the same time, GABA‐like immunoreactivity disappears in most neuropil areas of the brain and becomes faint in many immunoreactive somata. Neurons with arborizations in the ventrolateral protocerebrum, however, continue to exhibit intense immunostaining during this period, and strongly immunolabeled fibers connect these areas with the ventral nerve cord. The second phase of transformation begins around pupal stage P5/P6, when faint immunostaining appears in many previously nonimmunoreactive somata and most neuropil areas of the brain. In subsequent stages (P8–P10), this immunoreactivity disappears again in most somata, but in certain cell groups, it becomes more intense and gradually develops to the adult pattern. Most larval GABA‐immunoreactive neurons appear to survive through metamorphosis into the adult. Neurons in the midbrain that acquire GABA‐like immunoreactivity during metamorphosis usually lie adjacent to larval immunostained neurons, suggesting common lineages. The onsets of the two developmental phases of GABA‐like immunoreactivity correlate with sharp rises in hemolymph titers of ecdysteroid hormones, suggesting a role for ecdysteroids in the regulation of GABA synthesis. We hypothesize that the disappearance of GABA in many areas of the brain starting 2 days prior to pupation dramatically alters its functional circuitry and thus may account for profound changes in the behavior of the animal. © 1994 Wiley‐Liss, Inc.
Synaptic interrelationships between the optic tectum and the ipsilateral nucleus isthmi in Rana pipiens
Authors: Gruberg Edward R. , Hughes Thomas E. , Karten Harvey J.
Published: January 2005

The nucleus isthmi is reciprocally connected to the ipsilateral optic tectum. Ablation of the nucleus isthmi compromises visually guided behavior that is mediated by the tectum. In this paper, horseradish peroxidase (HRP) histochemistry and electron microscopy were used to explore the synaptic interrelationships between the optic tectum and the ipsilateral nucleus isthmi. After localized injections of HRP into the optic tectum, there are retrogradely labeled isthmotectal neurons and orthogradely labeled fibers and terminals in the ipsilateral nucleus isthmi. These terminals contain round. Clear vesicles of medium diameter (40–52 nm). These terminals make synaptic contact with dendrites of nucleus isthmi cells. Almost half of these postsynaptic dendrites are retrogradely labeled, indicating that there are monosynaptic tectoisthmotectal connections.

Localized HRP injection into the nucleus isthmi labels terminals primarily in tectal layers B, E, F, and 8. The terminals contain medium‐sized clear vesicles and they form synaptic contacts with tectal dendrites. There are no instances of labeled isthmotectal terminals contacting labeled dendrites. Retrogradely labeled tectoisthmal neurons are contacted by unlabeled terminals containing medium‐sized and small clear vesicles. Fifty‐four percent of the labeled fibers connecting the nucleus isthmi and ipsilateral tectum are myelinated fibers (average diameter approximately 0.6 μm). The remainder are unmyelinated fibers (average diameter approximately 0.4 μm). © 1994 Wiley‐Liss, Inc.
Auditory nerve terminals in the cochlear nucleus magnocellularis: Differences between low and high frequencies
Authors: Köppl Christine
Published: January 2005

Primary auditory nerve fibers were labelled in the barn owl by localized horseradish peroxidase (HRP) injections into the cochlear nucleus angularis. They were followed to their terminal sites in the hearing organ (basilar papilla), confirming that they were auditory, and to the cochlear nucleus magnocellularis. The terminal sites of low‐frequency fibers within nucleus magnocellularis always included an area previously described as the lagenar part, i.e., an area receiving primary input which is probably only vestibular. Furthermore, a number of differences were recognized between these low‐frequency (up to 0.64 kHz) and the high‐frequency (1.8 kHz and above) auditory nerve projections to nucleus magnocellularis. Most importantly, the collaterals given off by low‐frequency fibers into the nucleus typically showed multiple terminal branching, with both en passant and terminal bouton‐like swellings. High‐frequency fiber collaterals, in contrast, terminated unbranched in a single endbulb of Held. Nucleus magnocellularis is the first station in a brainstem auditory pathway processing stimulus timing information, coded through neuronal phase locking. The prominent difference in terminal shape found between its low‐ and high‐frequency input fibers is interpreted as reflecting different requirements of the absolute temporal precision for significant phase locking. Terminals in the shape of endbulbs of Held are probably a specialization to improve the temporal precision of synaptic transmission, allowing phase locking to higher frequencies. © 1994 Wiley‐Liss, Inc.
Age‐related increase in the total number of corticotropin‐releasing hormone neurons in the human paraventricular nucleus in controls and alzheimer's disease: Comparison of the disector with an unfolding method
Authors: Raadsheer F. C. , Oorschot D. E. , Verwer R. W. H. , Tilders F. J. H. , Swaab D. F.
Published: January 2005

It has been hypothesized that the corticotropin‐releasing hormone (CRH) neurons of the hypothalamic paraventricular nucleus (PVN) become hyperactive with age, and even more so in Alzheimer's disease. This hyperactivity could be due to an increased production of CRH per neuron, or an increased number of PVN neurons producing CRH, or both. As a first step in elucidating which of these biological mechanisms might be operative, we have estimated the absolute number of CRH immunoreactive neurons in the PVN of 10 human control subjects between 36 and 91 years of age and 10 Alzheimer patients between 40 and 97 years of age. CRH neurons were immunocytochemically detected in 6 μm paraffin sections with the aid of a highly specific monoclonal antibody to CRH. The antibody signal was amplified by the biotinstreptavidin and alkaline phosphatase methods. The absolute number of CRH neurons in the PVN was obtained by multiplying the number of CRH neurons in a unit volume (Nv) by the total volume of the PVN. Two different methods were used to estimate the Nv: an unfolding method and a disector method (about three times more time‐consuming). Compared to the disector, the unfolding method consistently yielded a lower cell number for all patients by 38% (± 2.8%; mean ± SEM). However, both methods yielded an increase in the absolute number of CRH neurons in control and Alzheimer patients with age. No statistically significant difference in the absolute number of CRH neurons was found between control and Alzheinler patients with both methods. The age‐dependent increase in the absolute number of CRH neurons within the PVN of both control and Alzheimer patients is interpreted as a sign of activation of the CRH neurons with age. © 1994 Wiley‐Liss, Inc.
Tenascin in the injured rat optic nerve and in non‐neuronal cells in vitro: Potential role in neural repair
Authors: Ajemian A. , Ness R. , David S.
Published: January 2005

The distribution of tenascin was examined in the lesioned adult rat optic nerve and central nervous system (CNS) non‐neuronal cells in vitro, by means of a double immunofluorescence technique. Tenascin‐like immunoreactivity is localized to the leptomeninges and astrocytes that border the site of optic nerve transection. Anti‐tenascin labeling was observed as early as 24 hours after transection, when it appeared as a fine interface between leptomeninges and neural tissue. The anti‐tenascin labeling increased in the cells at this border zone during the next 2 weeks, and disappeared 18–21 days after transection. In vitro studies further confirmed that both astrocytes and leptomeningeal cells express tenascin as detected by immunofluorescence labeling with anti‐tenascin antibodies. However, the pattern of immunolabeling associated with the two cell types differed. Astrocytes showed exclusively punctate labeling of the cell surface, while leptomeningeal cells showed mainly coarse, fibrillary, matrix‐like deposits. Astrocytes and leptomeningeal cells remained segregated when cocultured. In these cultures, an increased amount of the fibrillary, matrix‐like deposits of tenascin was also observed in the region of the interface between astrocytes and leptomeningeal cells when these two cell types contact each other. Given the antiadhesive and antispreading properties of tenascin, these in vivo and in vitro results suggest that tenascin might playa role in the initial segregation of leptomeningeal cells from neural tissue at the site of CNS trauma during the first 2 weeks after injury, i.e., prior to the formation of a fully differentiated glia limitans. Therefore, tenascin may influence the early stages in the formation of the glia limitans, and thus prevent the indiscriminate migration of leptomeningeal cells into CNS tissue after injury. © Wiley‐Liss, Inc.
Enkephalin‐positive and acetylcholinesterase‐positive patch systems in the superior colliculus have matching distributions but distinct developmental histories
Authors: Graybiel A. M. , Illing R.‐B.
Published: January 2005

Histochemical stains for acetylcholinesterase activity and enkephalin‐like immunoreactivity both demonstrate a high degree of patterning in the superior colliculus, particularly in the intermediate and deep layers. Both markers occur predominantly in the neuropil of these layers, and both are principally distributed in distinct macroscopic compartments. We report here that patches of heightened acetylcholinesterase activity correspond to patches of high enkephalin‐like immunoreactivity. The two markers thus delineate largely the same domain in the intermediate and deep layers. The most prominent zones of staining for enkephalin‐like peptide and for acetylcholinesterase also coincided in the dorsolateral periaqueductal gray matter. These findings suggest a close interlocking of one or more acetylcholinesterasecontaining systems with one or more pathways related to endogenous opioids in the superior colliculus. As the acetylcholinesterase expression in the patches is known to match in detail choline acetyltransferase expression, our results also suggest the possibility of local cholinergicopiatergic interactions.

In some sections, blood vessels associated with enkephalin‐rich and acetylcholinesteraserich patches extended beyond the colliculus into the periaqueductal gray matter, where they again became surrounded by dense fibrous labeling. This pattern suggests that neurohumoral signal exchange might occur through blood vessels even in a sensory‐motor structure such as the colliculus.

In a postnatal developmental series of kitten brains we found that enkephalin‐like immunoreactivity was already distinctly compartmental in the intermediate layers at birth and continued to show this distribution throughout postnatal development. By contrast, acetylcholinesterase staining was nearly homogeneous at birth and became compartmental gradually during the first postnatal weeks. Thus, despite the eventual near coincidence of the enkephalinrich and acetylcholinesterase‐rich compartments of the superior colliculus, they mark systems that follow distinct programs of neurochemical development. © Wiley‐Liss, Inc.
Effects of estrogen on the number of neurons expressing β‐endorphin in the medial basal hypothalamus of the female guinea pig
Authors: Thornton Janice E. , Loose Michael D. , Kelly Martin J. , Rönnekleiv Oline K.
Published: January 2005

The distribution pattern of immunoreactive β‐endorphin neurons was studied in female guinea pigs that were ovariectomized, and one week later were injected with 25 μg estradiol benzoate or oil. The animals (5 from each group) were perfused after 24 hours with 4% paraformaldehyde. The locations of β‐endorphin cells and fibers were determined using avidin‐biotin immunohistochemistry on free‐floating vibratome sections. β‐endorphin‐immunoreactive fibers were distributed widely throughout specific regions of the rostral forebrain, similar to what has been described in other species. β‐endorphin cell bodies were found in the arcuate nucleus and in adjacent ventrolateral areas throughout the rostrocaudal extent of the basal hypothalamus. Cells immunoreactive to β‐endorphin were also present in the caudal part of the ventromedial nucleus of the hypothalamus. The number of β‐endorphin neurons was quantified in anatomically matched sections through the rostral, medial and caudal basal hypothalamus of estradiol benzoate‐ and oil‐treated guinea pigs. Analysis of variance revealed that the number of immunoreactive β‐endorphin cells was significantly increased in all regions of the basal hypothalamus of estrogen‐treated guinea pigs as compared to vehicle‐treated animals (P < 0.01). These data indicate that in the guinea pig, the number of neurons expressing β‐endorphin is increased in the arcuate nucleus 24 hours after estrogen treatment.
Local circuit neurons immunoreactive for calretinin, calbindin D‐28k or parvalbumin in monkey prefronatal cortex: Distribution and morphology
Authors: Condé Françoise , Lund Jennifer S. , Jacobowitz David M. , Baimbridge Kenneth G. , Lewis David A.
Published: January 2005

In the cerebral cortex, local circuit neurons provide critical inhibitory control over the activity of pyramidal neurons, the major class of excitatory efferent cortical cells. The calciumbinding proteins, calretinin, calbindin, and parvalbumin, are expressed in a variety of cortical local circuit neurons. However, in the primate prefrontal cortex, relatively little is known, especially with regard to calretinin, about the specific classes or distribution of local circuit neurons that contain these calcium‐binding proteins. In this study, we used immunohistochemical techniques to characterize and compare the morphological features and distribution in macaque monkey prefrontal cortex of local circuit neurons that contain each of these calcium‐binding proteins.

On the basis of the axonal features of the labeled neurons, and correlations with previous Golgi studies, calretinin appeared to be present in double‐bouquet neurons, calbindin in neurogliaform neurons and Martinotti cells, and parvalbumin in chandelier and wide arbor (basket) neurons. Calretinin was also found in other cell populations, such as a distinctive group of large neurons in the infragranular layers, but it was not possible to assign these neurons to a known cell class. In addition, although the animals studied were adults, immunoreactivity for both calretinin and calbindin was found in Cajal‐Retzius neurons of layer I. Dual labeling studies confirmed that with the exception of the Cajal‐Retzius neurons, each calcium‐binding protein was expressed in separate populations of prefrontal cortical neurons.

Comparisons of the laminar distributions of the labeled neurons also indicated that these calcium‐binding proteins were segregated into discrete neuronal populations. Calretinin‐positive neurons were present in greatest density in deep layer I and layer II, calbindin‐immuno‐reactive cells were most dense in layers II‐superficial III, and parvalbumin‐containing neurons were present in greatest density in the middle cortical layers. In addition, the relative density of calretinin‐labeled neurons was approximately twice that of the calbindin‐ and parvalbumin‐positive neurons. However, within each group of labeled neurons, their laminar distribution and relative density did not differ substantially across regions of the prefrontal cortex.

These findings demonstrate that calretinin, calbindin, and parvalbumin are markers of separate populations of local circuit neurons in monkey prefrontal cortex, and that they may be useful tools in unraveling the intrinsic inhibitory circuitry of the primate prefrontal cortex in both normal and disease states.