bluuebunny/crossref_metadata_2025 huggingface dataset:
Immunocytochemical localization of midbrain estrogen receptor‐ and progestin receptor‐containing cells in female guinea pigs
Authors: Turcotte Joanne C. , Blaustein Jeffrey D.
Published: January 2005

In the guinea pig midbrain, a low concentration of progestin receptors is induced by estradiol. This is in contrast to the mediobasal hypothalamus which has a large number of estradiol‐induced progestin receptors. Because the midbrain is an important site for the hormonal regulation of sexual behavior, we mapped the distribution of cells containing estrogen receptor‐ and estradiol‐induced progestin receptor‐immunoreactivity in that area. Estrogen receptor‐immunoreactive cells are found in midbrain sites previously reported, including the midbrain central gray, the tegmentum lateral and ventral to the central gray, peripeduncular region, and parabrachial nuclei. While progestin receptor‐immunoreactive cells were not detected without estradiol priming, estradiol‐induced progestin receptors were found throughout the rostrocaudal extent of the midbrain central gray and adjacent tegmental area. Progestin receptor‐immunoreactive cells were far fewer than estrogen receptor containing cells, had less cytoplasmic staining, and appeared restricted to the midbrain central gray, lateral and ventrolateral to the cerebral aqueduct and the adjacent tegmental area. © 1993 Wiley‐Liss, Inc.
Topography of descending projections from the inferior colliculus to auditory brainstem nuclei in the rat
Authors: Caicedo Alejandro , Herbert Horst
Published: January 2005

We examined the organization of descending projections from the inferior colliculus (IC) to auditory brainstem nuclei and to pontine and reticular nuclei in the rat by employing the anterograde axonal tracer Phaseolus vulgaris‐leucoagglutinin (PHA‐L). Small PHA‐L injections into cytologically defined subnuclei of the IC revealed that each subnucleus has a unique pattern of efferent projections.

The central nucleus of the IC projects in a topographic order to the dorsal nucleus of the lateral lemniscus (DLL), the rostral periolivary nucleus (RPO), the ventral nucleus of the trapezoid body (VNTB), and the dorsal cochlear nucleus (DCN). It is assumed that this topography represents a cochleotopic arrangement. The external cortex of the IC projects to the nucleus sagulum (Sag), the RPO, the VNTB, and the DCN. Minor projections were found to pontine and reticular nuclei. Efferent fibers from the dorsal cortex of the IC terminate mainly in the Sag, while other nuclei of the auditory and extra‐auditory brainstem receive only minor projections. The intercollicular zone sends a moderate number of fibers to the DLL and very few, if any, to the remaining auditory brainstem nuclei. In contrast, fairly strong projections from the intercollicular zone to the reticular formation were found.

The present data demonstrate that the four subnuclei of the IC have a differential pattern of descending projections to nuclei in the pontine and medullary brainstem. These parallel colliculofugal pathways, assumed to belong to functionally separate circuits, may modulate auditory processing at different levels of the auditory neuraxis. © 1993 Wiley‐Liss, Inc.
Cells of origin of the spinoparabrachial fibers in the rat: A study with fast blue and WGA‐HRP
Authors: Kitamura Taiko , Yamada Jinzo , Sato Hitoshi , Yamashita Kazuo
Published: January 2005

The internal lateral (IL) subnucleus of the parabrachial nucleus (PB), which is one of the seven lateral subnuclei of the PB, receives information from the spinal cord. The IL subnucleus perhaps relays nociceptive signals to the intralaminar nuclei of the thalamus, apparently being implicated in the motivational‐affective component of pain reaction. However, cells of origin of spinal fibers to the IL subnucleus have not been investigated sufficiently. We intended to clarify these cells by injection of fast blue or wheat germ agglutinin‐conjugated horseradish peroxidase into the IL subnucleus and/or other lateral subnuclei in the rat. When the tracer was injected into the IL subnucleus, many cells were labeled bilaterally in laminae I, V, and VII, and in the dorsolateral and dorsomedial parts of the lateral funiculus throughout the entire length of the spinal cord. A small number of labeled cells appeared ipsilaterally in laminae II–IV and VI in the upper cervical segments and contralaterally in laminae VIII and X throughout the spinal cord. Labeled cells in lamina I were more numerous ipsilaterally than contralaterally in the first two cervical segments but were more numerous contralaterally than ipsilaterally in the remaining spinal segments. Labeled cells were seen with a contralateral predominance in lamina VII, but with an ipsilateral predominance in lamina V and in the dorsolateral and dorsomedial parts of the lateral funiculus. With tracer injected into the lateral subnuclei of the PB, excluding the IL subnucleus, labeled cells were found primarily in lamina I throughout the entire length of the spinal cord. These results show that cells giving rise to spinoparabrachial fibers were more numerous and more widely distributed than previously reported. © 1993 Wiley‐Liss, Inc.
Neuropeptides and a neuronal marker in cutaneous innervation during human foetal development
Authors: Terenghi G. , Sundaresan M. , Moscoso G. , Polak J. M.
Published: January 2005

There is evidence that foetal body movements first occur at 6 weeks gestation, and that the reflex arc is functional at 8 weeks. This correlates with the detection of the sensory neuropeptides calcitonin gene‐related peptide (CGRP) and substance P (SP) in spinal cord at 10 weeks gestation. However, the development of cutaneous neuropeptide‐containing nerves is not well documented in humans. We have investigated the early appearance and distribution pattern of CGRP, SP, vasoactive intestinal peptide (VIP) and neuropeptide Y (NPY), as well as those of the general neuronal marker protein gene product 9.5 (PGP) in various areas of foetal skin at different gestational ages. PGP‐immunoreactive nerves were first seen in the subepidermal plexus at 6 weeks gestational age. Initially, the immunoreactive nerves are thick, club‐shaped and distributed in the superficial dermis. Beaded adult‐like fibres become more numerous only at later ages (10–12 weeks), and extend from this plexus to penetrate the epidermis. Histologically, the skin of the hand develops faster than that of other body areas and at 9 weeks, more PGP‐immunoreactive nerves were seen in the palm than in the dorsum. Primitive sweat glands were first noted in axillary skin at 17 weeks, accompanied by a few PGP‐immunoreactive nerves. Occasional, small CGRP‐immunoreactive fibres were first noticed in the dermis at 7 weeks, but it was at 17 weeks that the presence of this neuropeptide was unequivocal in the subepidermal plexus. Sparse VIP‐, SP‐ and NPY‐immunoreactive fibres were not found until 16–17 weeks gestation, when they were seen in the dermis and around small blood vessels. These results show that development of nerves containing sensory neuropeptides precedes that of autonomic fibres, and that the former are present in developing cutaneous innervation after neuronal protein markers are detectable. The timing of the appearance of CGRP immunoreactivity in the skin correlates with that of the peptide in spinal cord, which is consistent with the reported reflex movements of the foetus. The morphological and functional development of cutaneous neuronal elements shows a close correlation that might provide some insight into the process of nerve regeneration in adult skin. © 1993 Wiley‐Liss, Inc.
An aromatase‐associated cytoplasmic inclusion, the “stigmoid body,” in the rat brain: II. Ultrastructure (with a review of its history and nomenclature)
Authors: Shinoda Koh , Nagano Mamoru , Osawa Yoshio
Published: January 2005

The ultrastructure of aromatase‐associated “stigmoid (dot‐like) structures,” which were detected in a previous study using light‐microscopic immunohistochemistry (Shinoda et al.: J. Comp. Neurol. 322:360–376, '92), were examined in the rat medial preoptic region, bed nucleus of the stria terminalis, medial amygdaloid nucleus, and arcuate nucleus by pre‐ and post‐embedding marking with a polyclonal antibody against human placental antigen X‐P2 (hPAX‐P2) for immuno‐electron microscopic analysis. The immunoreactive stigmoid structure was identified as a distinct, non‐membrane‐bounded cytoplasmic inclusion (approximately 1–3 μm in diameter), which has a granulo‐fuzzy texture with moderate‐to‐low electron density in non‐immunostained preparations. It consists of at least four distinct granular and three distinct fibrillo‐tubular elements forming a granulo‐fibrillar conglomerate. This type of inclusions was formally termed the “stigmoid body” under the electron microscope. The stigmoid body is composed of the outer granulo‐fibrillar and inner hyaloplasmic compartments. The immunoreactivity for hPAX‐P2 is mainly localized to the former, especially to the low density granulo‐fuzzy materials associated with the fibrillo‐tubular elements. Identification of the ultrastructure of stigmoid body clarified their prevalence not only in the limbic and hypothalamic regions, but also in sex‐steroid‐sensitive peripheral tissues (e.g., peripheral sensory ganglia, ovary, testis) by consulting earlier electron‐microscopic studies.

Reviewing the history and nomenclature of this inclusion body, we reorganized the terminology of related neuronal cytoplasmic inclusions, the terms of which have often been confused, and discussed its functional significance on the basis of the present and previously accumulated data. In conclusion, we emphasized the importance of the stigmoid bodies in the sex‐steroid‐sensitive neural system because of their large size, high frequency, specific distribution in brains and peripheral tissues, effects of sex‐steroids, and immunological and histochemical characteristics of the antibody marking the inclusion. The stigmoid bodies may provide a subcellular site for sex‐steroid metabolism in their target tissues and play a critical role in cytosolic modulation of their actions (e.g., by aromatization) prior to their receptor binding. © 1993 Wiley‐Liss, Inc.
The organization of the descending ventral pallidal projections in the monkey
Authors: Haber S. N. , Lynd‐Balta E. , Mitchell S. J.
Published: January 2005

This study describes the organization and topography of the descending efferent projections from the monkey ventral pallidum. The main efferent projections from the globus pallidus are to the subthalamus, to the thalamus, and to the substantia nigra. Although these projections have been well established for the dorsal pallidum, the projections of the ventral pallidum have not been explored in primates. The results of this study add an important link in how information from the limbic lobe is channeled through the basal ganglia in monkeys.

Anterograde tracers, Phaseolus vulgaris‐leucoagglutinin, and tritiated amino acids were injected into various regions of the ventral pallidum. The descending efferent projection from the ventral pallidum in monkeys terminates primarily in the subthalmaic nucleus and adjacent lateral hypothalamus, in the substantia nigra, and in the lateral habenular nucleus. Although terminals are also found in the thalamus, these are relatively sparse. The projections to the subthalamic nucleus and the lateral hypothalamus are topographically arranged, while those to the substantia nigra are not.

These results suggest that pathways from distinct pallidal regions that receive specific striatal input terminate in distinct regions of the subthalmic/hypothalamic regions, thus maintaining a topographic arrangement. Projections to the substantia nigra, however, overlap extensively, suggesting convergence of terminals from different ventral pallidal regions. The relatively small projection to the thalamus raises the question that without a prominent thalamic projection, is this system parallel to that described for the dorsal globus pallidus? © Wiley‐Liss, Inc.
Morphology and somatotopy of the central arborizations of rapidly adapting glabrous skin afferents in the rat lumbar spinal cord
Authors: Shortland Peter , Woolf Clifford J.
Published: January 2005

The central arborizations in the dorsal horn of the spinal cord of 23 rapidly adapting (RA) A‐beta primary afferent neurons innervating different regions of the glabrous skin of the hindpaw were studied by the intra‐axonal injection of horseradish peroxidase in adult rats. A total of 284 arbors of the complex, simple, and blind‐ending variety were recovered. The arbors of RA afferents innervating the toes, paw pads, and non‐pad hindpaw differed from each other in branch pattern and dimensions. The simple and complex arbors, which are both bouton‐containing, were distributed mainly in laminae III–V, although some complex arbors projected dorsally into lamina IIi.

The hindpaw glabrous skin afferent terminals were located in the lumbar enlargement from caudal L3 to rostral L6. A crude somatotopic organization was observed such that toes 1–5 were represented successively in more caudal positions from mid‐L4 to caudal L5. The paw pads were organized in a rostrocaudal sequence moving from the paw pads proximal to toe 1 across the foot to the paw pads proximal to toe 5, from caudal L3 to mid‐L5. Non‐pad hindpaw afferents were located in caudal L5. Overlap between toe, paw pad and non‐pad afferent central fields was present, however, and the central terminals of afferents with non‐adjacent peripheral receptive fields were shown to occupy the same region of the dorsal horn. © 1993 Wiley‐Liss, Inc.
Differential expression of neuron‐glia cell adhesion molecule (Ng‐CAM) on developing axons and growth cones of interneurons in the chick embryo spinal cord: An immunoelectron microscopic study
Authors: Shiga Taskashi , Shirai Toshio , Grumet Martin , Edelman Gerald M. , Oppenheim Ronald W.
Published: January 2005

To elucidate the role of neuron‐glia cell adhesion molecule (Ng‐CAM) in axonal pathway formation of avian spinal interneurons, we have examined the ultrastructural expression of Ng‐CAM in the developing spinal cord, by using a preembedding immunocytochemical method. Ng‐CAM immunoreactivity was punctate and was restricted to cell surfaces. In accordance with our previous light microscopic observations (Shiga et al., '90), the earliest developing spinal interneurons were Ng‐CAM‐positive on their cell bodies, axons, and growth cones. Axons and growth cones that were either fasciculated or in contact with each other strongly expressed Ng‐CAM, thus indicating the possible involvement of Ng‐CAM in fasciculation of axons and in the contact guidance of growth cones along preexisting axons. By using higher resolution immunoelectron microscopy, the present study has also revealed new information on the subcellular localization of Ng‐CAM on developing spinal interneurons, neuroepithelial cells, and floor plate cells. Although Ng‐CAM immunoreactivity was prominent on both axons and growth cones, these structures were Ng‐CAM‐negative when they contacted the basal lamina around the spinal cord. By contrast, Ng‐CAM was detectable on the surface of both neuroepithelial cells and floor plate cells only when they made contact with the Ng‐CAM‐positive axons and growth cones of interneurons. These results suggest that the subcellular distribution of Ng‐CAM is regulated differentially, depending on the apposing cell surfaces, and that such differential and developmentally regulated expression may contribute to the elongation, fasciculation, and guidance of spinal axons. © 1993 Wiley‐Liss, Inc.
Immunocytochemical localization of atrial natriuretic factor (ANF)‐like peptides in the brain and heart of the treefrog Hyla japonica: Effect of weightlessness on the distribution of immunoreactive neurons and cardiocytes
Authors: Feuilloley Marc , Yon Laurent , Kawamura Kosuke , Kikuyama Sakae , Gutkowska Jolanta , Vaudry Hubert
Published: January 2005

The localization of atrial‐natriuretic factor (ANF)‐like immunoreactivity was investigated in the brain and heart of the treefrog Hyla japonica by the indirect immunofluorescence technique. Concurrently, the effect of weightlessness on the distribution of ANF‐containing neurons and cardiocytes was studied in frogs that were sent into space for 9 days on the space station „MIR.”︁ In control animals, the amygdala contained the most prominent group of ANF‐immunoreactive cells and fibers. ANF‐positive neurons and nerve processes were also detected in other areas of the telencephalon such as the nucleus olfactorius, the pallium mediale, and the striatum. In „space frogs,”︁ the intensity of labeling of the amygdala and nucleus olfactorius was similar to that seen in control animals. In contrast, the pallium and the striatum of „space frogs”︁ were totally devoid of positive cell bodies. In the diencephalon, of all animals, numerous ANF‐immunoreactive perikarya and fibers were seen in the hypothalamus, the anterior thalamus, the infundibulum, and the median eminence. ANF‐positive cell bodies were also noted in the lateral forebrain bundle of control frogs but were absent in „space frogs.”︁ The major difference between control and „space frogs”︁ was observed in the posterior nuclei of the thalamus. In „space frogs,”︁ the nucleus posterocentralis thalami and the nucleus posterolateralis thalami exhibited large ANF‐immunoreactive perikarya, while, in control frogs, these nuclei only contained scarce positive nerve fibers. In the mesencephalon, ANF‐positive cell bodies and nerve processes were seen in the nucleus tegmenti mesencephali, the interpeduncular nucleus, and the nucleus cerebelli of all animals. However, stained perikarya were only observed in the nucleus reticularis isthmi of control frogs. In the heart, atrial cardiocytes exhibited intense ANF‐like immunoreactivity. ANF‐positive myocytes were also detected in the subpericardial region of the ventricle. The density and distribution of the staining were identical in the heart of control and „space frogs.”︁ These data support the concept that prolonged exposure to microgravity affects biosynthesis and/or release of ANF‐related peptides in discrete regions of the amphibian brain.
First appearance, distribution, and origin of macrophages in the early development of the avian central nervous system
Authors: Cuadros Miguel A. , Martin Claude , Coltey Pierre , Almendros Antonio , Navascués Julio
Published: January 2005

A phagocytic cell system of hemopoietic origin exists in the early avian embryo (Cuadros, Coltey, Nieto, and Martin: Development 115:157–168, '92). In this study we investigated the presence of cells belonging to this system in the central nervous system (CNS) of chick and quail antibodies recognizing cells of quail hemangioblastic lineage. The origin of these cells was traced in interspecific chick–quail yolk sac chimeras. Hemopoietic cells were detected within the CNS from developmental stage HH15 on, and steadily increased in number at subsequent stages. Analysis of yolk sac chimeras revealed that most of these cells were of yolk sac origin, although some hemopoietic cells of intraembryonic origin were also found in the CNS.

Immunocytochemical, histochemical, and ultrastructural characterization allowed us to identify hemopoietic cells in the CNS as macrophages. These cells were consistently found in the brain vesicles and spinal cord, appearing (1) between undifferentiated neuroepithelial cells at dorsal levels of the CNS; (2) in areas of cell death; (3) in the marginal layer in close relationship with developing axons; (4) in large extracellular spaces in the subventricular layer; (5) on vascular buds grwoing through the marginal and subventricular layers; and (6) in the ventricular lumen. Macrophages in different locations varied in morphology and ultrastructure, suggesting that in addition to their involvement in phagocytosis, they play a role in other processes in the developing CNS, such as axonal growth and vascular development.

The first macrophages migrate to the CNS independently of its vascularization, apparently traversing the pial basal lamina to reach the nervous parenchyma. Other macrophages may enter the CNS together with vascular buds at subsequent stages during CNS vascularization.
Relay cells, not interneurons, of cat's lateral geniculate nucleus contain N‐acetylaspartylglutamate
Authors: Xing Li‐Chuan S. , Tieman Suzannah Bliss
Published: January 2005

N‐Acetylaspartylglutamate (NAAG) is an endogenous brain dipeptide that satisfies many of the criteria for a neurotransmitter. We have previously identified NAAG immunoreactivity in neurons of the lateral geniculate nucleus (LGN) of the cat and monkey. To determine whether all LGN neurons contain NAAG, we treated sections of cat LGN with affinity‐purified antibodies to NAAG and counterstained them with thionin. The larger neurons contained NAAG, but the smaller neurons did not. We treated other sections with antiserum to glutamic acid decarboxylase (GAD), the rate‐limiting enzyme in the synthesis of γ‐aminobutyric acid (GABA), in order to label interneurons of the LGN. In these sections, the smaller cells were labeled; the larger neurons were not. We hypothesized that NAAG was present in relay cells, but not interneurons. We used two double‐labeling paradigms to test this hypothesis. We combined immunocytochemistry for NAAG using a fluorescent secondary antibody with either (1) fluorescent retrograde tracers (true blue, granular blue, rhodamine beads, or propidium iodide) injected into areas 17 and/or 18 or (2) immunocytochemistry for GAD using a second fluorescent secondary antibody. In the LGN, over 99% of retrogradely labeled cells contained NAAG, but few GAD‐positive neurons did. In contrast, neurons of the perigeniculate nucleus contained both NAAG and GAD, demonstrating that staining by one set of antisera did not inhibit staining by the other and that perigeniculate neurons are chemically distinct from the interneurons of the LGN. We conclude that in LGN, the relay cells, which project to visual cortex, contain NAAG, whereas most of the interneurons, which contain GABA, do not.
Neuroanatomical distribution and binding properties of saxitoxin sites in the rat and turtle CNS
Authors: Xia Ying , Haddad Gabriel G.
Published: January 2005

Since saxitoxin (STX) binds to voltage‐sensitive sodium channels and blocks their function, it has been widely used in the study of these channels. There is, however, limited information on STX binding properties and the neuroanatomical distribution of the Na+ channel as a function of brain region in the rat and in lower vertebrates such as the turtle. In the present study, we used a broad range of 3H‐STX concentration (up to 64 nM) to examine saturation profiles and density distribution in both adult rat and turtle brains. We found that (1) STX sites do not vary greatly in affinity (most Kds = 2 to 5 nM) in various regions of the adult rat brain; (2) STX binding distribution was very heterogeneous in the rat with much higher density in the cortex, hippocampus, amygdala, and cerebellum than in the brainstem and spinal cord; (3) STX sites are mostly localized in layers made mostly of neurons with low density in white matter; and (4) turtle brain STX sites had similar binding properties, but its brain had much fewer STX sites than the rat, especially in the cerebellum and rostral areas such as the cortex. We conclude that (a) adult brain sodium channels have similar STX binding affinity in spite of the existence of multiple sodium channel subtypes; (b) the brainstem is very different from rostral brain areas in channel density; and (c) the turtle brain has a much lower sodium channel density than the rat brain.
Intracellular injection of neurobiotin or horseradish peroxidase reveals separate types of preganglionic neurons in the sacral parasympathetic nucleus of the cat
Authors: Morgan Charles W. , De Groat W. C. , Felkins L. A. , Zhang S.‐J.
Published: January 2005

Sacral preganglionic neurons are essential to the neural control of the excretory and sex organs. Previously employed multi‐cell tracing methods have certain limitations in the precise morphological analysis of the neural pathways that control these organs. These limitations were overcome by the intracellular injection of neurobiotin or horseradish peroxidase into single preganglionic neurons in the lateral sacral parasympathetic nucleus of the cat. Following light microscopic examination, these neurons, as a group, were found to have an average of five stem dendrites, which divided into 15 dendritic end‐branches that were distributed among eight dendritic terminal fields. These dendrites had a major transverse orientation and were quite long, many of them reaching well into the dorsal and ventral horns and into the dorsal gray commissure. These dendrites also exhibited a major longitudinal orientation, extending an average of 869 μm (combined length of rostral and caudal dendrites) within the nucleus. Two groups of cells emerged on the basis of different dendritic patterns. Cells classed as Type I had dendrites in lamina I and in the ventral horn but lacked a significant projection into the lateral funiculus. Cells classed as Type II had major dendritic projections into the lateral funiculus but lacked dendrites in lamina I. The diverse dendritic patterns of these two cell types indicate dissimilar afferent control mechanisms and suggest that these preganglionic neurons may innervate different target organs. © 1993 Wiley‐Liss, Inc.
Compartmental origin of the striato‐entopeduncular projection in the rat
Authors: Rajakumar N. , Elisevich K. , Flumerfelt B. A.
Published: January 2005

The mammalian neostriatum is divisible into neurochemically and cytoarchitectonically distinct striosome and matrix compartments. This compartmentalization is respected by many afferent and efferent projections of the striatum. The distribution of distinct types of neuroactive substances and receptors and the unique connections of the striosome and matrix suggest a functional segregation between these compartments. The present study examines the organization of efferent projections from each of the striatal compartments to the entopeduncular nucleus (EPN), a major output cente of the basal ganglia.

The fluorescent retrograde tracer fluorogold, or rhodamine‐conjugated dextran, was injected into the lateral habenula or the ventrolateral nucleus of the thalamus of adult Wistar rats to identify the topographical organization of EPN‐habenular and EPN‐thalamic neurons. Fluorogold was then placed into the rostral or caudal parts of the EPN, identified from the previous experiment as areas containing predominantly EPN‐habenular or EPN‐thalamic neurons, respectively. Sections containing retrogradely labeled neurons in the neostriatum were simultaneously immunolabeled for calbindin‐D28kDa, a calcium‐binding protein found exclusively in the projection neurons of the matrix. The results indicate that the striatal projection to the EPN‐habenular and EPN‐thalamic parts of the EPN originates from striosome and matrix neurons, respectively. The duality of striatal outflow involving the EPN suggests a mechanism whereby the striosome is integrated into subcortical pathways that modulate the activity of the basal ganglia via the ascending serotoninergic projection from the dorsal raphe nucleus, whereas the matrix is involved in a loop that includes the thalamus and the cerebral cortex. © 1993 Wiley‐Liss, Inc.
Ipsilaterally projecting retinal ganglion cells in Xenopus laevis: An HRP study
Authors: Schütte Michael , Hoskins Sally G.
Published: January 2005

The routes of ipsilaterally projecting retinal ganglion cell axons in the visual pathway of young postmetamorphic Xenopus laevis were studied by anterograde and retrograde transport of horseradish peroxidase (HRP). In the retina, most cells heavily labeled from injections in ipsilateral thalamus are large multipolar ganglion cells. They are found exclusively in the posterior half of the retina, and their axons occupy a central position in the optic nerve head. Immediately behind the eye, axons of ipsilaterally projecting axons leave the core of the nerve and regroup around the circumference of the nerve. The nerve increases in diameter in the region where the fibers reorganize, and pigmented processes are seen in this region of the nerve. At the point where the optic nerve enters the brain case through the optic foramen, the fibers undergo a second reorganization which results in a laminar arrangement of ipsilaterally projecting axons at the ventral margin of the intracranial portion of the nerve. As soon as the nerve touches the brain, uncrossed axons begin to turn toward the ipsilateral side rather than proceeding further towards the midline of the chiasm. These uncrossed axons keep their internal topographical order at least at the beginning of the marginal tract. All ipsilaterally projecting axons run at the rostral edge of the marginal tract at the lateral‐wall of the brain until they reach their terminal fields in the thalamic visual nuclei. © 1993 Wiley‐Liss, Inc.
Purkinje cell dendrites in staggerer ↔ wild type mouse chimeras lack the aberrant morphologies found in lurcher ↔ wild type chimeras
Authors: Soha James M. , Herrup Karl
Published: January 2005

In lurcher ↔ wild type mouse chimeras (lurcher chimeras), mutant Purkinje cells are transiently present and probably provide target support for afferent granule cells during the sensitive period of target‐dependent cell death. Previous studies demonstrate that wild type Purkinje cells in the cerebella of mature lurcher chimeras often have atrophic dendritic morphologies, leading to the hypothesis that development deafferentation of wild type Purkinje cells occurs uniquely in lurcher chimeras following the period of mutant Purkinje cell loss. Other studies document the survival of a disproportionately large number of granule cells in these animals. Based on cell birthdate analyses, the hypothesis further proposes that deafferentation induces an up‐regulation of trophic activity among the Purkinje cell population and the consequent rescue of late generated granule cells that might otherwise be lost to target related cell death. In the present study, we take advantage of phenotypic differences between the staggerer and lurcher mutations to test this hypothesis. While staggerer ↔ wild type chimeras (staggerer chimeras) resemble lurcher chimeras in several respects, including extensive cell loss, they differ in that staggerer Purkinje cells never provide target support for granule cells. Hence the hypothesis predicts that Purkinje cells in these animals should not exhibit the atrophic morphologies found in lurcher chimeras. We have developed a new semiquantitative method for scoring dendritic morphology in a large number of Golgi‐impregnated cells. We have used this method to characterize the distribution of wild type Pukinje cell morphologies in staggerer chimeras, and to compare these with the corresponding distributions of morphologies in lurcher chimeras and wild type ↔ wild type chimeras. We find that morphologies in staggerer chimeras closely resemble those in control chimeras. Furthermore, Purkinje cells in both staggerer and wild type chimeras differ significantly from those in lurcher chimeras. These results confirm a direct prediction of the hypothesis. © 1993 Wiley‐Liss, Inc.
Spatial and temporal differences between the expression of short‐ and middle‐wave sensitive cone pigments in the mouse retina: A developmental study
Authors: Szél Á. , Röhlich P. , Mieziewska K. , Aguirre G. , van Veen T.
Published: January 2005

In an earlier study we found a topographic separation of middlewave‐sensitive (M) and shortwave‐sensitive (S) cones in the adult mouse retina. In the present study we investigated the development of the two colour‐specific cone types to see whether there is also a temporal difference between the expression of the specific cone visual pigments. Using two anti‐cone visual pigment antibodies, COS‐1 and OS‐2, we compared the densities of immunopositive cone outer segments on retinal whole mounts derived from mice of various ages. The first detectable cone outer segments were the S‐cones which appeared in the inferior half of the retina on postnatal day 4. At this stage, the density of the S‐cones was very low (30–40 cones/retina) but increased steadily on the following days to reach a value comparable to that of adults by P30 (18,000/mm2). This cone type always remained much more abundant in the lower part of the retina throughout the whole retinal development. In the superior half of the retina, a few S‐cones appeared from postnatal day 7; however, their number always remained about one order of magnitude lower than in the inferior part.

In contrast, M‐cone outer segments were not identifiable earlier than postnatal day 11 and were confined exclusively to the superior part of the retina during the whole development process. On postnatal day 12, their density was 1,900/mm2 and increased to a value of 11,000/mm2 by postnatal day 30, which represented the adult stage. As shown by comparison of isodensity lines derived from immunocytochemical reactions of whole mount retinas, the two cone types occupied complementary halves of the mouse retina with maximum density centres located in opposite retinal quadrants. We conclude that (1) in contrast to the primate retina, mouse S‐cones precede the M‐cones in their development, and (2) the spatial arrangement of the two cone types is maintained throughout the whole differentiation process. © 1993 Wiley‐Liss, Inc.
2‐DG uptake patterns related to single vibrissae during exploratory behaviors in the hamster trigeminal system
Authors: Jacquin Mark F. , McCasland James S. , Henderson Theodore A. , Rhoades Robert W. , Woolsey Thomas A.
Published: January 2005

Stimulation of one or several whiskers activates discrete foci throughout the trigeminal (V) neuraxis. These foci contribute to patterns, corresponding to the patterns of vibrissae, that have been directly related to aggregates of cells and axon terminals in the “barrel” cortex. Here, we combine high‐resolution, 2‐deoxyglucose (2DG) mapping and cytochrome oxidase (CO) staining to determine whether the known pattern of V primary afferent projections is sufficient to deduce the functional activation of their targets during exploratory behavior. Four adult hamsters had all of their large mystacial vibrissae trimmed acutely, except for C3 on the left, and B2 and D4 on the right; in two others, the left C3 and right A1 and E4 whiskers were spared. After fasting overnight, 2DG was injected and the animals behaved freely in the dark for 45 minutes. The brainstem, thalamus, and cortices were sectioned, then processed for both CO staining and 2DG autoradiography. Image‐processing microscopy was used to separate the autoradiographic silver grains from the histochemical staining.

CO patches were patterned in a whiskerlike fashion in the full rostrocaudal extent of V nucleus principalis and in caudal portions of spinal V subnuclei interpolaris and caudalis, but absent in subnucleus oralis. 2DG silver grains were densest above those CO patches in the pattern corresponding to the active whiskers. There were no consistent 2DG foci in subnuclei oralis or rostral caudalais. In these same cases, prominent 2DG labeling was restricted to the appropriate barrels in the contralateral cortex. Only one case, however, displayed a clear and appropriate region of heightened 2DG uptake in contralateral ventroposteromedial thalamus (VPM) and the adjacent part of the reticular thalamic nucleus.

Patterns of increased glucose utilization with single whisker stimulation are well matched to the CO patterns that mirror distributions of neurons associated with a vibrissa in the V brainstem complex, thalamus, and cortex. Single whiskers are represented by relatively homogeneous longitudinal columns of 2DG labeling in the V brainstem nuclei. The columns are not continuous through the axial extent of the V brainstem complex; rather, they occur separately within principalis, interpolaris, and caudalis. While whisker columns were consistently labeled in interpolaris and caudalis in all animals, the labeling was increasingly variable in principalis, barrel cortex, and VPM, respectively. This suggests that the behaving animal can and does significantly modulate activity in this major, synaptically secure pathway. © 1993 Wiley‐Liss, Inc.
Spinal cord afferent systems containing the nerve terminal protein NT75
Authors: Kanekar Shami S. , Ritchie Teresa C. , Coulter Joe D.
Published: January 2005

In the adult spinal cord, immunocytochemical staining for NT75 is concentrated in nerve terminals in the superficial laminae of the dorsal horn. Deeper laminae of the dorsal horn contain moderate immunocytochemical labeling, but the ventral horn is only sparsely stained. The origin of spinal nerve terminals containing NT75 was investigated with lesion techniques, colchicine treatment, and retrograde tracing in combination with immunocytochemical staining. Primary afferent neurons express NT75 immunoreactivity and account for most of the dense staining in the superficial dorsal horn and part of the labeling in the deeper laminae. It was found that corticospinal and virtually all brainstem neurons with descending projections to the spinal cord also express NT75 immunoreactivity, including those terminating in the ventral horn. Colchicine treatment of the spinal cord also resulted in NT75 staining in most, if not all, spinal neurons. It appears that neurons in all three major sources of spinal afferents (primary sensory, descending, and intrinsic systems) can express NT75 immunoreactivity, but that some neurons normally contain higher levels of the protein in their nerve terminals. Previous analysis of developing spinal cord has shown widespread, dense NT75 labeling throughout the spinal gray in the early postnatal period, which later becomes restricted to the adult pattern. These studies support the hypothesis that many spinal pathways express high levels of NT75 immunoreactivity during development, but that only certain pathways maintain high levels in the adult. © 1993 Wiley‐Liss, Inc.
Immunocytochemical staining of AII‐amacrine cells in the rat retina with antibodies against parvalbumin
Authors: Wäussle Heinz , Grüunert Ulrike , Röhrenbeck Jürgen
Published: January 2005

The rod dominated rodent retina is the preferred tissue for in vitro studies of mammalian retinal physiology and pharmacology. The rod pathway through the rat retina was investigated, therefore, in order to find out whether its organization follows the mammalian “plan.” AII‐amacrine cells of the rat retina were injected with Lucifer Yellow to characterize the morphology of this bistratified interneuron of the rod pathway. When sections or whole mounts of the rat retina were stained with antibodies against the calcium binding protein parvalbumin (PV), two different amarcine cell types were labeled: the AII‐amacrine cell and a widefield amacrine cell. They occur at a ratio of 12:1. Weak label was also observed in ganglion cells. The density of PV‐labeled AII‐cells decreases from approximately 7,000 cells/mm2 in upper central retina to 2,000 cells/mm2 in peripheral retina. Their cell bodies form a regular mosaic, and the dendritic arbors of three neighbouring AII‐amacrine cells overlap (coverage of 3). © Wiley‐Liss, Inc.
Immunoelectron microscopic analysis of a novel carbohydrate differentiation antigen (CDA‐3C2) in the developing rat olfactory and otic systems
Authors: Prouty Stephen M. , Levitt Pat
Published: January 2005

A carbohydrate differentiation antigen (CDA‐3C2) exhibits a highly specific and restricted pattern of expression during rat embryogenesis. In the periphery of the embryo, this antigen is associated transiently with the lateral ectoderm but is retained only in the olfactory and otic epithelium throughout morphogenesis. At the light microscopic level, CDA‐3C2 immunoreactivity appears mostly along cell periphery and in the extracellular matrix. The aim of the present study was to determine the specific cellular and subcellular distribution of CDA‐3C2 in vivo in order to identify potential sites of cellular and tissue function of the antigen during embryogenesis. There was a strikingly similar subcellular distribution of CDA‐3C2 in the developing otic and olfactory systems, found mostly along cell membranes, microvillar projections and acellular secretions of the epithelium. Mature sensory components of the epithelia were not immunoreactive, whereas supportive cells and their secreted structures were densely stained. The highly coincident nature of CDA‐3C2 in both sensory epithelia suggests that this carbohydrate epitope, and possibly its carrier macromolecule, participate in a morphogenetic function common to these two sensory epithelia. © Wiley‐Liss, Inc.
Immunocytochemical study of GABAA receptors in the cat visual cortex
Authors: Gu Qiang , Perez‐Velazquez Jose L. , Angelides Kimon J. , Cynader Max S.
Published: January 2005

The laminar distribution and morphological structures associated with GABAA receptor immunoreactivity in the cat visual cortex were studied by using two different polyclonal antibodies directed either against the purified GABAA receptor protein (antibody “967”) or against a specific domain of the β1‐subunit of the GABAA receptor (antibody “Q”). Immunoblots of cat visual cortex tissue with these antibodies revealted that antibody “Q” recognizes only one subunit, namely the β1‐subunit of the GABAA receptor, and that antibody “967” recognizes three subunits. Both antibodies produced very similar staining patterns, indicating that the β1‐subunit may be an essential component of the GABAA receptor in the cat visual cortex. The typical staining pattern showed a clear membrane structure around neuronal somata. Using cell body shape criteria, immunopositive neurons included both pyramidal cells in cortical layers II, III, and V, and nonpyramidal cells in all cortical layers. Immunopositive neurons were uniformly distributed in layers II to VI, whereas the density of immunopositive cells in layer I was lower. Some immunopositive neurons were also found in the white matter underlying the visual cotex. In gray matter, immunopositive structures also included dendrites, especially the proximal dendrites, and axon initial segments of pyramidal neurons. The immunopositive processes usually ran vertically toward the pial surface. Some astrocytes were also immunostained. They were localized in layer I and in the white matter. The overall pattern of immunostaining was similar in areas 17, 18, and 19. © 1993 Wiley‐Liss, Inc.
Sequential differentiation of sensory innervation in the mystacial pad of the ferret
Authors: Mosconi T. M. , Rice F. L.
Published: January 2005

The mystacial pad of the ferret has an elaborate sensory innervation provided by three types of terminal nerves that arise from the infrorbital branch of the trigeminal nerve. Deep and superficial vibrissal nerves innervate nearly exclusive targets in the large follicle–sinus complexes (F‐SCs) at the base of each tactile vibrissa. Dermal plexus nerves innervate the fur between the vibrissae. Each type of nerve provides a similar variety of sensory endings, albeit to different targets. In this study, Winkelmann and Sevier‐Munger reduced silver techniques revealed that most of the endings differntiate postnatally in an overlapping sequence like that observed previously in the rat. Afferents from the deep vibrissal nerves begin to differentiate first, followed successively by those from superficial vibrissal nerves and the dermal plexus. Within each type of nerve, Merkel endings begin to differentiate first, followed successively by lanceolate endings and circumferential endings. In the ferret, the differentiation of the intervibrissal fur and its innervation is slightly delayed but substantially overlaps the development of the vibrissal innervation, whereas in the rat it occurs almost entirely later. There was no evidence of a transient exuberant or misplaced innervation or other secondary remodeling. Differentiating afferents and endings are located only in the sites normally seen in the adult, suggesting a high degree of afferent‐target specificity. In the ferret, innervation is virtually lacking in one target—the inner conical body of the F‐SCs, which is densely innervated in the rat. This lack was due to a failure of innervation to develop rather than to a secondary elimination of a transient innervation. © 1993 Wiley‐Liss, Inc.
Developmental regulation of Fos and Fos‐related antigens in cerebral cortex, striatum, hippocampus, and cerebellum of the rat
Authors: Alcantara Adriana A. , Greenough William T.
Published: January 2005

Previous work has associated the proto‐oncogene c‐fos with such events as neuronal excitation and cell growth and differentiation. This study specifically examined the expression of the Fos protein as well as other Fos‐related antigens (Fras) during postnatal development of rat brain. Ages P1 through P15 as well as adult animals (P60) were examined. Particular focus was placed on developing cerebral cortex, striatum, hippocampus, and cerebellum. We used both the Alu antiserum, which recognizes the Fos protein specifically, and the M5 antiserum, which recognizes both Fos and a family of Fos‐related antigens.

Fos and Fras were developmentally regulated in a region‐ and cell‐specific manner. Differential nuclear and cytoplasmic labeling appeared age dependent. Transient Fos expression was generally followed by a more protracted time course of Fra expression. Fos and a delayed or an extended expression of Fras were observed in subplate neurons between P1 and P15, in striatal striosome and matrix neurons between P1 and P9, and in hippocampal pyramidal neurons between P1 and P9. Fras alone were expressed in cerebral cortex pyramidal neurons and other cortical neurons between ages P1 and P15. Fos and Fras were concomitantly expressed in piriform and entorhinal cortical neurons between P1 and P9 and in cerebellar Purkinje cells between ages P5 and P10. Constitutive levels of Fos and Fras remained detectable in adult animals in a subset of cerebral cortical neurons and cerebellar Purkinje neurons. © 1993 Wiley‐Liss, Inc.