bluuebunny/crossref_metadata_2025_split huggingface dataset:
Embryonic (PSA) N‐CAM reveals chains of migrationg neuroblasts between the lateral ventricle and the olfactory bulb of adult mice
Authors: Rousselot P. , Lois C. , Alvarez‐Buylla A. 
Published: January 2005

AbstractIn the brain of adult mice, cell division persists in the subventricular zone (SVZ) of the lateral ventricles. These SVZ cells migrate rostrally 3–5 mm to the olfactory bulb, where they differentiate into neurons. We have investigated the distribution of PSA‐N‐CAM in the adult mouse forebrain. Immunoreactivity for PSA‐N‐CAM precisely reveals the migratory pathway of SVZ cells. This pathway of PSA‐N‐CAM positive cells starts in the lateral wall of the lateral ventricle, where immunopositive cells form weblike patterns. The PSA‐N‐CAM positive pathway extends rostrally between the corpus callosum and the striatum into the anterior ventral telencephalon, and then into the core of the olfactory bulb. Experiments in which [3H]‐thymidine was injected systemically indicated that the majority of the dividing cells on the SVZ of the lateral ventricle and along the migratory pathway are positive to PSA‐N‐CAM or closly associated with PSA‐N‐CAM. Microinjection of [3H]‐thymidine into the SVZ of the lateral ventricle to label a small patch of dividing SVZ cells shows that neuroblasts that migrated away from the injection site are positive or are closely associated with other cells that are positive for PSA‐N‐CAM. Migrating cells are tethered together, forming long chains of immunopositive cells. The migratory pathway is formed by 30–40 of these immunopositive chains. Radially oriented individual PSA‐N‐CAM positive cells were observed in the olfactory bulb. These cells seem to have broken away from chains of immunopositive cells in the core of the olfactory bulb and to be migrating to more superficial layers. Little is known about the mechanisms of tangential migration during development and in adulthood. The cell‐cell arrangement revealed by PSA‐N‐CAM staining suggests new models for this form of neuronal migration. PSA‐N‐CAM staining suggests new models for this form of neuronal migration. PSA‐N‐CAM localization along the migratory pathway to the olfactory bulb suggests that in the adult brain this molecule plays a role in migration of neuronal precursors. © 1995 Willy‐Liss, Inc.
Dendritic reorganisation in the basal forebrain under degenerative conditions and its defects in Alzheimer's disease. II. Ageing, Korsakoff's disease, Parkinson's disease, and Alzheimer's disease
Authors: Arendt Thomas , Brückner Martina K. , Bigl Volker , Marcova Lena 
Published: January 2005

AbstractChanges in the dendritic arborisation of Golgi‐impregnated basal forebrain neurones with respect to size, shape, orientation, and topology of branching were quantitatively investigated in ageing, Alzheimer's disease (AD), Korsakoff's disease (KD), and Parkinson's disease (PD). A reorganisation of the whole dendritic tree characterized by an increase in both the total dendritic length and the degree of dendritic arborisation as well as by changes in the shape of the dendritic field was found during ageing, in KD, PD, and AD. Dendritic growth under these conditions was related to the extent of cell loss in basal forebrain nuclei. There appeared to be major differences, however, with respect to the overall pattern of dendritic reorganisation between AD on one side and ageing, KD, and PD on the other side. In both ageing and KD, dendritic growth was largely restricted to the terminal dendritic segments, resulting in an increase of the size of the dendritic field (pattern of “extensive growth”). In AD, aberrant growth processes were frequently observed in the perisomatic area or on distal dendritic segments of basal forebrain neurones of the reticular type. Neurones with aberrant growth profiles were typically located in the direct vicinity of deposits of β/A4 amyloid. Perisomatic growth profiles were covered by the low‐affinity receptor of nerve growth factor p75NGFR. Aberrant growth processes were not present in ageing, KD, and PD. On the basis of the present study, it is concluded that under certain degenerative conditions, reticular basal forebrain neurones undergo a compensatory reorganisation of their dendritic arborisation, a process that has become defective in AD, thereby converting a physiological signal into a cascade of events contributing to the pathology of the disease. © 1995 Willy‐Liss, Inc.
Enhanced but delayed axonal sprouting of the commissural/associational pathway following a combined entorhinal cortex/fimbria fornix lesion
Authors: Schauwecker P. Elyse , McNeill Thomas H. 
Published: January 2005

AbstractFrom previous lesion studies of the hippocampus it has been reported that axons of the commissural/associational pathway expand their termination zone in the molecular layer of the dentate gyrus by 20–25% in response to loss of input from the entorhinal cortex. However, although much is known about the response of the commissural/associational pathway with regard to extent, latency, and speed of the reinnervation response following an entorhinal cortex lesion, little is known about how the loss of additional afferent systems might modulate this response. To address this issue, we examined at 14, 30, and 45 days postlesion, the sprouting of commissural/associational afferents following either a unilateral fimbria fornix transection, a unilateral entorhinal cortex lesion, or combined lesions of both the entorhinal cortex and the fimbria fornix. Loss of septal innervation to the hippocampus was assessed using the cholinesterase stain, whereas sprouting from the commissural/associational pathway was determined from Holmes fiber‐stained sections. In addition, the Timms stain was used to examine the time course of the loss of terminal fields of the various zinc‐containing afferent systems within the hippocampus.Following the removal of input to the hippocampus via the fimbria fornix transection, there was no evidence of sprouting of the commissural/associational fibers into the deafferented portion of the dentate gyrus. In contrast, rats receiving an entorhinal cortex lesion showed a significant increase (28%) in the width of the commissural/associational fiber plexus that was present by 14 days postlesion. By comparison, the magnitude of the expansion of the commissural/associational fiber plexus was significantly larger after lesioning both the entorhinal cortex and the fimbria than after the entorhinal cortex lesion alone (45% vs. 28%). In addition, the expansion of the commissural/associational fiber plexus that was not increased at 14 days postlesion but was significantly increased at 30 days postlesion. The delay in the sprouting of the commissural/associational pathway coincided with the time course of loss of zinccontaining fibers in the outer molecular layer of the dentate gyrus as assessed with the Timms stain. These results suggest that the magnitude and time course for the sprouting of axons from the commissural/associational pathway into the partially deafferented hippocampus of the adult rat is lesion dependent and that the effect of the loss of input from the entorhinal cortex can be modulated and enhanced by the concomitant depletion of input from the fimbria fornix. © 1995 Willy‐Liss, Inc.
The efferent projections of the periaqueductal gray in the rat: A Phaseolus vulgaris‐leucoagglutinin study. I. Ascending projections
Authors: Cameron Adrian A. , Khan Iqbal A. , Westlund Karin N. , Cliffer Kenneth D. , Willis William D. 
Published: January 2005

AbstractThis study has examined the ascending projections of the periaqueductal gray in the rat. Injections of Phaseolus vulgaris‐leucoagglutinin were placed in the dorsolateral or ventrolateral subregions, at rostral or caudal sites. From either region, fibers ascended via two bundles. The periventricular bundle ascended in the periaqueductal and periventricular gray matter. At the posterior commissure level, this bundle divided into a dorsal component that terminated in the intralaminar and midline thalamic nuclei, and a ventral component that supplied the hypothalamus. The ventral bundle formed in the deep mesencephalic reticular formation and supplied the ventral tegmental area, substantia nigra pars compacta, and the retrorubral field. The remaining fibers were incorporated into the medial forebrain bundle. These supplied the lateral hypothalamus and forebrain structures, including the preoptic area, the nuclei of the diagonal band, and the lateral division of the bed nucleus of the stria terminalis.The dorsolateral subregion preferentially innervated the centrolateral and paraventricular thalamic nuclei and the anterior hypothalamic area. The ventrolateral subregion preferentially innervated the parafascicular and central medial thalamic nuclei, the lateral hypothalamic area, and the lateral division of the bed nucleus of the stria terminalis. Although the dorsolateral and ventrolateral subregions gave rise to differential projections, the projections from both the rostral and caudal parts of either subregion were similar. This suggests that the dorsolateral and ventrolateral subregions are organized into longitudinal columns that extend throughout the length of the periaqueductal gray. These columns may correspond to those demonstrated in recent physiological studies. © 1995 Willy‐Liss, Inc.
Structure and innervation of longitudinal and transverse abdominal muscles of the cricket, gryllus bimaculatus
Authors: Kawasaki Fumiko , Kita Hiroshi 
Published: January 2005

AbstractDetailed morphological and physiological studies on the insect abdominal muscles, including their innervation and neuromuscular transmission, are essential for understanding their important role in respiratory movements. There are both longitudinal and transverse muscles in the ventral abdominal segments of the cricket, Gryllus bimaculatus. Muscle 202 was selected as an example of a longitudinal muscle. This muscle is, on average, 1.4 mm long, paired on both sides of the abdomen, and consists of 127 fibers whose mean maximum diameter is 32 μm; the average sarcomere length is 8.1 μm. It is innervated by two ipsilateral motoneurons in the second abdominal ganglion, the axons of which run in the ipsilateral first nerve root of the third abdominal ganglion. Two motor axons run in parallel from the two cell bodies and innervate in close proximity. Accordingly, large and small excitatory junctional potentials (EJPs) are recorded from the same fiber with slightly different thresholds when the first nerve root of the third abdominal ganglion is stimulated. Muscle 203, which is a transverse muscle that extends across the fifth abdominal sternum and is located over the fourth abdominal ganglion and muscle 202 on both sides, is, on average, 2.9 mm long and consists of 86 fibers with a maximum diameter of 33 μm. The average sarcomere length is 7.9 μm. The right or left half of the muscle is innervated mainly by a contralateral motoneuron in the third abdominal ganglion through the ipsilateral first nerve root of the third abdominal ganglion. Nerve branches of the first nerve root also reach muscles 188 and 218. Muscle 203 is additionally innervated by the first nerve roots of abdominal ganglia 1, 2, and 4. These innervations were ascertained both electrophysiologically and histologically. Individual muscle fibers of muscle 203 produced small EJPs in response to stimulation of the first nerve roots of abdominal ganglia 2, 3, and 4 and large EJPs in response to stimulation of the root from the first abdominal ganglion. The large and small EJPs in muscle 203 have properties similar to those in muscle 202. © 1995 Wiley‐Liss, Inc.
Corticostriatal connections of extrastriate visual areas in rhesus monkeys
Authors: Yeterian E. H. , Pandya D. N. 
Published: January 2005

AbstractThe striatal connections of extrastriate visual areas were examined by the autoradiographic technique in rhesus monkeys. The medial as well as the dorsolateral extrastriate regions project preferentially to dorsal and lateral portions of the head and of the body of the caudate nucleus, as well as to the caudodorsal sector of the putamen. The rostral portion of the annectant gyrus has connections to the caudal sector of the body and to the genu, whereas projections from the caudal portion of the lower bank of the superior temporal sulcus are directed to dorsal and central sectors of the head and the body, to the genu and the tail, as well as to the caudal putamen. The ventrolateral extrastriate region is related mainly to the ventral sector of the body, to the genu and the tail, and to the caudal putamen. In contrast, the striatal projections of the ventromedial extrastriate cortex resemble those of the medial and dorsolateral regions. The caudal inferotemporal cortex is related strongly to the tail of the caudate nucleus and to the ventral putamen.The differential corticostriatal connectivity of the various extrastriate regions may contribute to the specific functional roles of these cortices. Thus, the connections from the dorsomedial, dorsolateral, and ventromedial areas to dorsal portions of the caudate nucleus and of the putamen may serve a visuospatial function. In contrast, the connections from the ventrolateral extrastriate and inferotemporal regions to the tail of the caudate nucleus and to the ventral putamen may have a role in visual object‐related processes. © 1995 Wiley‐Liss, Inc.
Basal expression of the inducible transcription factors c‐Jun, JunB, JunD, c‐Fos, FosB, and Krox‐24 in the adult rat brain
Authors: Herdegen Thomas , Kovary Karla , Buhl Anja , Bravo Rodrigo , Zimmermann Manfred , Gass Peter 
Published: January 2005

AbstractJun, Fos, and Krox proteins are inducible transcription factors contributing to the control of gene expression. The elucidation of their individual expression patterns in the nervous system provides new insights into the ability of neurons to react with changes of gene expression to external stimulation under physiological or pathological conditions. The expression of c‐Jun, JunB, JunD, c‐Fos, FosB, and Krox‐24 was investigated in the brain of untreated male Sprague‐Dawley and female BDIX rats by immunocytochemistry using specific antibodies.JunD immunoreactivity (IR) labeled the highest number of neurons, being present in almost all neurons of the brain. JunD was expressed at high levels in those areas that also exhibit c‐Jun, JunB, c‐Fos, and FosB‐IR, such as locus coeruleus, periolivary nuclei (ncl.), pontine and central gray, lateral lemniscal ncl., inferior and superior colliculi, leaflet of geniculate ncl., midline nuclei of thalamus, dorsomedial and paraventricular ncl. of hypothalamus, ncl. supraopticus, dorsolateral part of caudate putamen and lateral septal ncl. In contrast to the high number of JunD‐positive neurons, c‐Jun, JunB, c‐Fos, and FosB proteins were detected in rather low numbers of neurons in these brain areas; the rank of the number of immunopositive neurons was c‐Fos > JunB > c‐Jun > FosB. Particularly high levels of expression were observed for c‐Jun in medullary motoneurons, medial geniculate ncl., arcuate ncl., and dentate gyrus, and for JunB in the CA‐1 area of the hippocampus and islands of Calleja. The zinc finger protein Krox‐24 was expressed in many neurons of these brain areas, with only discrete Jun‐ and Fos‐IR; additionally, many intensely labeled nuclei were present in spinal ncl. of the trigeminal ventromedial ncl. of the hypothalamus and the CA‐1 area of the hippocampus. In the cerebellum, nuclear labeling was detected only for c‐Jun, JunD, and Krox‐24 in granule cells, JunD‐IR was also found in glial cells of gray matter and fiber tracts, whereas glial c‐Jun‐IR was observed only in fiber tracts. Apart from a weak JunD‐IR, some areas did not express Jun, Fos, and Krox proteins such as cuneate and gracile ncl., venterobasal. complex of thalamus, globus pallidum, and Purkinje cells of the cerebellum.Our data indicate that inducible transcription factors of the fos, jun, and krox gene families show patterns of individual expression in untreated animals, thereby reflecting different mechanisms and/or thresholds for induction under physiological conditions. © 1995 Wiley‐Liss, Inc.
Brain‐derived neurotrophic factor‐transduced fibroblasts: Production of BDNF and effects of grafting to the adult rat brain
Authors: Lucidi‐Phillipi Carrie A. , Gage Fred H. , Shults Clifford W. , Jones Kevin R. , Reichardt Louis F. , Kang Un Jung 
Published: January 2005

AbstractLocal delivery of brain‐derived neurotrophic factor (BDNF) by genetically modified cells provides the unique opportunity to examine the effects of BDNF on adult dopaminergic and cholinergic neurons in vivo. Primary rat fibroblasts were genetically engineered to produce BDNF. Conditioned media from BDNF‐transduced fibroblasts supported embryonic chick dorsal root ganglion neurons as well as rat fetal mesencephalic neurons. BDNF‐transduced fibroblasts grafted to the rat brain survived and showed continued mRNA production for at least 2 weeks. The effects of BDNF‐transduced fibroblast grafts on the dopaminergic and cholinergic systems were then assessed. BDNF‐transduced fibroblasts grafted into the normal intact substantia nigra induced sprouting of tyrosine hydroxylase‐ and neurofilamentimmunoreactive fibers into the graft. Fibroblast grafts implanted into the normal intact striatum and midbrain as well as the 6‐hydroxydopamine‐lesioned brain did not induce sprouting of dopaminergic fibers; neither did they affect drug‐induced rotational behavior. BDNF‐transduced fibroblasts did, however, significantly increase the homovanillic acid/dopamine ratio when grafted into the normal midbrain. Following transection of the fimbriafornix, BDNF‐transduced fibroblasts grafted into the septum were unable to rescue the septal cholinergic population, as did nerve growth factor‐producing fibroblast grafts. Genetically modified fibroblast grafts may provide an effective, localized method of BDNF delivery in vivo to test biological effects of this factor on the central nervous system. © 1995 Wiley‐Liss, Inc.
Genetic control of retinal projections in inbred strains of albino mice
Authors: Rice Dennis S. , Williams Robert W. , Goldowitz Dan 
Published: January 2005

AbstractMutations in the tyrosinase gene are often associated with a misrouting of retinal ganglion cell axons at the optic chiasm. In albinos, tyrosinase activity is lost and some ganglion cell axons that would normally project into the ipsilateral optic tract instead cross midline and project into the contralateral tract. The developmental mechanisms that cause this modification in neuronal connectivity are unknown. In this study, we screened six diverse strains of albino mice (strains 129, A, AKR, BALB/c, C57BL/6‐c/c, and CD‐1) to discover genetically determined variations and possible gene loci that might affect the severity of the albino decussation abnormality. Ganglion cells were retrogradely labeled with horseradish peroxidase, and the ipsilaterally and contralaterally projecting cells were counted. The average number of ipsilaterally projecting ganglion cells in the six albino strains varies from 1,000 to 1,300. Despite this variation, 1.8–1.9% of the total population projects ipsilaterally in each strain. In comparison, 2.8% project ipsilaterally in the pigmented strain, C57BL/6‐+/+. However, the percentage of displaced, ipsilaterally projecting cells varies substantially among albino strains‐from a low of 4% in strain CD‐1 to a high of nearly 10% in C57BL/6‐c/c. We conclude that even with large differences in genetic background and in absolute numbers of ganglion cells, there is no appreciable variation in the magnitude of decussation error among albino mice. The consistent effect of null alleles at tyrosinase suggests a comparably tight linkage between the biochemical activity of this enzyme and the mechanisms that control decussation phenotype. © 1995 Wiley‐Liss, Inc.
Cellular distribution of iron, transferrin, and ferritin in the hypotransferrinemic (Hp) mouse brain
Authors: Dickinson Thomas K. , Connor James R. 
Published: January 2005

AbstractHypotransferrinemic (Hp) mice have a point mutation or small deletion in the transferrin (Tf) gene, resulting in defective splicing of precursor Tf mRNA. Hp animals produce 1% of normal Tf levels and require supplemental serum or purified Tf for survival. Because of the lack of endogenous brain Tf, we examined regional and cellular distributions of iron and iron regulatory proteins (Tf and ferritin) in selected brain regions of Hp mice. The regional distribution of iron, Tf, and ferritin in Hp brain was similar to normal except for the pattern of iron staining in hippocampus. The cellular distribution of iron, ferritin, and Tf was similar between Hp and normal animals. The predominant cell type, staining for Tf and iron was oligodendrocytes. Qualitative observations suggest that the number of cells staining for iron was similar between Hp and normal mice, whereas the number of Hp Tf‐positive cells was reduced. Ferritin immunostaining was similar in both cases. However, ferritin‐positive cells were preominantly astrocytes, an observation unique to mice among species studied previously. Western blot analysis revealed that Tf present in HP brain was of exogenous origin (from supplemental injections). Presumably, Tf transports the iron found in Hp oligodendrocytes. These data demonstrate that, despite reduced endogenous Hp brain Tf, iron and plasma Tf migrate or are transported to the appropriate cells (oligodendrocytes), bringing into question the role of endogenous brain Tf in extracellular iron transport.
Lateral superior olive projections to the inferior colliculus in normal and unilaterally deafened ferrets
Authors: Moore David R. , Russell F. Anne , Cathcart Nicki C. 
Published: January 2005

AbstractWe have examined the projection from the lateral superior olive (LSO) to the inferior colliculus (IC) in the ferret, with particular interest in the laterality of the projection and in the effects of unilateral cochlear removal in infancy. Large or small deposits of the retrograde tracer wheat germ agglutininhorseradish peroxidase (WGA‐HRP) were made in the IC of anesthetized adult ferrets that either were normally hearing or had been unilaterally deafened in infancy (P5 or P25). After 2 days, the ferrets were perfused, and frontal sections of the brainstem were treated with tetramethyl benzidine. For large deposits of WGA‐HRP, equal numbers of labelled neurons were found evenly spread through both LSOs. Smaller deposits of WGA‐HRP produced four results that contrasted with previous reports on the cat. First, many more labelled neurons were found in the contralateral than in the ipsilateral LSO. Second, the relative number of labelled neurons in each LSO was independent of whether the deposits were in the ventral or in the dorsal IC. Third, the total number of labelled LSO neurons was independent of whether the deposits were in the ventral or in the dorsal IC. Fourth, the proportion of ipsilateral to contralateral labelled neurons was slightly higher in the medial LSO than in the lateral LSO. Ventral IC deposits resulted in more labelled neurons in the medial LSO, and dorsal IC deposits resulted in more labelled neurons in the lateral LSO, as expected. Neonatal cochlear removal did not change any of these results. We conclude that, in the ferret, the organization of the crossed and uncrossed projections from the LSO to the IC differs from that of the cat, and any similarity with the optic chiasm is not obvious. © 1995 Wiley‐Liss, Inc.