bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of prenatal protein deprivation on postnatal development of granule cells in the fascia dentata
Authors: Diáz‐Cintra S. , Cintra L. , Galván A. , Aguilar A. , Kemper T. , Morgane P. J. 
Published: January 2005

AbstractThe effect of prenatal protein deprivation on the postnatal development of granule cells in the fascia dentata in the rat was studied at 15, 30, 90, and 220 days of age. The granule cells showed a significant reduction in cell size, decreased number of synaptic spines throughout their dendritic extent, and reduced complexity of dendritic branching in the outer two‐thirds of the molecular layer. All of these deficits were present at 15 days and persisted throughout the study (220 days). The least deficits in synaptic spine density occurred at 90 days and in dendritic branching at 30 days. Partial restitution of earlier, more severe deficits was associated primarily with maturational events occurring in the protein deprived rats, whereas later increases in deficits were related primarily to a failure of the protein deprived rats to keep pace with neuronal development occurring in the controls. The present results are similar to those noted in our previous study in this journal of the effect of a low protein diet (8% casein) on these neurons that extended from pregnancy until the time of sacrifice at 30, 90, and 220 days of age (Cintra et al, 1990; 532:271–277). Taken together, these two studies suggest that the postnatal adaptation of the granule cells to prenatal protein deprivation is primarily due to events that occur during pregnancy and that the site of predilection for the deficit is their dendrites in the outer two‐thirds of the molecular layer of the fascia dentat.
Alterations in afferent pathways from the urinary bladder of the rat in response to partial urethral obstruction
Authors: Steers William D. , Ciambotti Jonathan , Etzel Barbara , Erdman Susan , de Groat William C. 
Published: January 2005

AbstractAfferent pathways from the urinary bladder were examined with axonal tracing techniques in normal female Wistar rats and in those with partial urethral ligation. Following injection of wheat germ agglutinin‐horseradish peroxidase (HRP) into the bladder wall, HRP was detected in lumbosacral dorsal root ganglion cells and in afferent projections to the L6–S1 spinal cord at sites in laminae I, II, V–VII, and X known to receive visceral afferent input. Partial urethral ligation (6 weeks) produced a sixfold increase in bladder weight and altered the morphology of bladder afferent pathways. Changes included an increase in the average cross‐sectional area of labelled neuronal profiles in L6 and ST dorsal root ganglia in obstructed (766 ± 378 μm2, P < 0.001) compared to control rats (528 ± 189 μm2). The cross‐sectional area of the largest profiles also increased by approximately 40%. The mean number of labelled dorsal root ganglion cell profiles was similar in ligated (837 ± 198) and control (883 ± 352) groups. When compared to control animals the obstructed animals exhibited a 60% increase in the area of the labelled afferent terminal field in the intermediolateral region of the L6‐S1 spinal cord. This increased labelling was even more remarkable given that the volume of tracer per bladder weight injected into the hypertrophied bladder was 87% less than controls. These results provide evidence that bladder afferents project to regions of the spinal cord known to regulate micturition and that these afferents can undergo morphological alterations and/or changes in axoplasmic transport in response to urethral ligation. Changes may occur in response to increased target organ mass, increased neural activity, or alterations in the levels or activity of neurotrophic factors.
Architectonics of the parietal and temporal association cortex in the strepsirhine primate Galago compared to the anthropoid primate Macaca
Authors: Preuss Todd M. , Goldman‐Rakic Patricia S. 
Published: January 2005

AbstractA number of higher order association areas have been described in the parietal and temporal cortex of large‐brained anthropoid primates such as Macaca. However, little is known about the evolution of these areas, and the existence of homologous areas has not yet been clearly demonstrated in other mammalian groups. We addressed this issue by comparing the myelo‐ and cytoarchitecture of posterior association cortex in the anthropoid Macaca to that of the small‐brained, strepsirhine (“prosimian”) primate Galag.Our results suggest that Galago possesses many, if not most, of the areas present in Macaca. We were able to identify regions in Galago which resemble Macaca posterior parietal area 7, superior temporal polysensory cortex (ST), inferotemporal visual cortex (IT), the temporoparietal auditory area (Tpt), and posterior parahippocampal cortex (areas TH and TF). Area 7, ST, and IT can each be subdivided further in Macaca, and for most of these subdivisions we were able to identify counterparts in Galago. However, we could not distinguish as many divisions of ST cortex in Galago as in Macaca, and it is possible that new areas arose in this region during anthropoid evolution. There also appear to be general differences in architectonic organization between these animals, with Macaca exhibiting greater development of pyramidal layer IIIc and of the internal granular layer (IV) across much of the parieto‐temporal corte.These findings suggest that many, although possibly not all, of the parietal and temporal association areas present in the modern anthropoid Macaca evolved early in primate history, prior to the divergence of the lineages leading to strepsirhines and anthropoids.
Differential effect of functional olfactory bulb deafferentation on tyrosine hydroxylase and glutamic acid decarboxylase messenger RNA levels in rodent juxtaglomerular neurons
Authors: Stone Donna M. , Grillo Mary , Margolis Frank L. , Joh Tong H. , Baker Harriet 
Published: January 2005

AbstractExpression of the dopaminergic phenotype in olfactory bulb (OB) juxtaglomerular neurons (constituting a population of periglomerular and external tufted cells) is dependent upon functional innervation by peripheral olfactory receptors. Loss of functional input in rodents, by either peripheral deafferentation or deprivation of odorant access, results in a profound decrease in the expression of juxtaglomerular tyrosine hydroxylase (TH). We have examined the effects of such treatments on the expression of the neurotransmitter biosynthetic enzyme glutamic acid decarboxylase (GAD), which is colocalized with TH in the majority of TH‐containing juxtaglomerular neurons. Following either chemically induced OB deafferentation in adult mice or unilateral odor deprivation in neonatal rats, steady‐state OB GAD messenger RNA levels remained essentially unchanged as assessed by Northern blot analysis 20–40 days after treatment. These results were confirmed by in situ hybridization analysis, which demonstrated a profound loss of juxtaglomerular TH messenger RNA but no accompanying decrease in regionally colocalized GAD message. Since GAD is found in nearly all dopaminergic OB cells, the preservation of juxtaglomerular GAD message implies that olfactory receptor neurons exert a differential transneuronal regulation of TH and GAD gene transcription.
Cultured epithelioid astrocytes migrate after transplantation into the adult rat brain
Authors: Emmett Caroline J. , Lawrence Jean M. , Raisman Geoffrey , Seeley P. John 
Published: January 2005

AbstractA highly purified population of dividing epithelioid astrocytes has been prepared from postnatal rat corpus callosum. These cells were labelled in culture by incorporation of either [3H]thymidine or fluorescent microspheres and transplanted in a fibrin clot into the hippocampi of adult syngeneic rats. Transplanted cells divided in vivo and progressively migrated into the host brain from the site of implantation up to distances of about 1 mm. After a 1‐week survival, transplant cells stained strongly for glial fibrillary acidic protein and had the thick sinuous processes characteristic of stellate astrocytes. Artefactual transfer of radiolabel to host cells was ruled out by control experiments in which either the proportion of transplant cells that were radiolabelled was varied or radiolabelled transplant cells were killed prior to implantation. Astrocyte migration over the first days after implantation was determined to occur at a rate of approximately 100 μm per day. Transplant cells moved into both grey and white matter areas of the host brain and over the migratory period were commonly observed to be associated with blood vessels. Some transplant cells were directly juxtaposed against neuronal perikarya and dendrites. Many labelled astrocytes were located in areas that were apparently completely free of damage caused by implantation. These results define a class of mature astrocytic cells that have the ability to migrate through the adult brain. The existence of pathways for cell movement in the adult CNS has implications for the mechanisms of tissue remodelling after injury and transplantation, for regenerative repair of the CNS, and for the dynamics of cell‐cell contacts in the normal adult mammalian brain.
Ipsilateral cortical connections of primary somatic sensory cortex in rats
Authors: Fabri Mara , Burton Harold 
Published: January 2005

AbstractThe organization of ipsilateral cortical connections of the rat primary somatic sensory area (SI) was analyzed following small injections of multiple fluorescent tracers in the same case, into two or three SI body representations identified electrophysiologically. Labeling patterns were studied in tangential cortical sections and in flattened reconstructions from coronal sections. The cytochrome oxidase staining in tangential sections served as a control for injection location and to position labeling patterns found within granular portion of SI.The results show that most connections made with SI are reciprocal. Their topographical organization show different degrees of precision in the different areas. Homotypical and heterotypical connections were defined, the latter being more evident within the granular portion of SI. The findings: (1) were consistent with subdividing rat SI into four distinct areas with each having its own pattern of connections, (2) revealed two topographically organized regions in parietal cortex lateral to SI called second somatosensory (SII) and parietal ventral (PV) areas, (3) confirmed a topographical pattern in motor cortex and suggested an organization for connections between SI and an agranular medial field, and (4) demonstrated three more regions in parietal cortex connected to SI: posterior to SI called parietal medial; lateral to PV called parietal rhinal; posterior to SII called parietal lateral. Differences were noted in the distinctions between and within the maps when label distributions were plotted separately from supra‐ and infragranular layers. These findings agree with previous parcellations of the rat SI (Chapin et al., 1987: J. Comp Neurol 263:326–346), squirrel PV and SII (Krubitzer et al., 1986: J. Comp Neurol 250:403–430), and the organization of rat corticospinal neurons in many of the same areas (Li et al., 1990: Somat Motor Res 7:315–335).
Identification and distribution of microglial cells in the cerebral cortex of the lizard: A histochemical study
Authors: Castellano Bernardo , Gonzalez Berta , Dalmau Ishar , Vela Jose Miguel 
Published: January 2005

AbstractThe histochemical demonstration of nucleoside diphosphatase as a specific microglial marker was used to study the distribution of this glial cell type in the cerebral cortex of Podarcis muralis and Podarcis hispanica. Our results showed that in both species, NDPase staining was specific for the microglial cell population and that microglial cells displayed a specific localization pattern in the different cortical areas. In the medial cortex, microglial cells were principally found in the outer and inner plexiform layers in the strata adjacent to the granular layer. Moreover, some microglial cells were found near the ependymal layer, but no microglial cells were normally present near the brain surface and never in the deep inner plexiform layer. In the dorsomedial cortex, microglial cells were found near the brain surface in the outer plexiform layer, in the upper part of the granular layer, and near the ependymal layer. No microglial cells were found, however, in the outer and inner plexiform layers adjacent to the granular layer. Finally, in the dorsolateral cortex, microglial cells were located in the upper part of the outer plexiform layer, in and bordering the granular layer, and scattered in the inner plexiform layer. This layered‐pattern distribution of microglial cell population in the cerebral cortex of the lizard differs from the apparently homogeneous distribution of microglia in the brain of mammals.
Pattern formation in the striatum: Neurons with early projections to the substantia nigra survive the cell death period
Authors: Fishell Gord , Van Der Kooy Derek 
Published: January 2005

AbstractDuring the early postnatal period the striatum undergoes significant cell death. The specificity and regulation of this regressive event may be particularly interesting in the light of recent findings demonstrating that a developmentally organized compartmental architecture exists in the striatum. The striatum can be divided into two complementary and phenotypically distinct compartments, the patches and the matrix. In the adult, these two striatal compartments can be distinguished on the basis of their anatomy and a series of compartment‐specific biochemical and hodological markers. We have previously demonstrated that the neurons within the patch and matrix compartments become postmitotic and make connections with the substantia nigra at distinct and sequential developmental times. The majority of patch neurons become postmitotic between embryonic days 12 and 15 and make a striatonigral connection prenatally. In contrast, a majority of matrix neurons become postmitotic between embryonic days 17 and 20 and do not form an efferent connection to the substantia nigra until the first postnatal week. Here we investigated whether either neuronal birthdate or time of making an efferent projection correlates with a neuron's probability of surviving the cell death period. We found that both the patch and matrix compartments undergo their entire cell death period by the end of the first postnatal week. During this period approximately 30% of striatal neurons are subject to cell death, regardless of striatal compartment. Neuronal counts within the striatal patch compartment suggest that both early born neurons (embryonic day 13) and early projecting neurons (to the substantia nigra) are preferentially spared. However, their considerable overlap (i.e., most early born neurons also have a nigral projection) prevents assessment of which feature is critical for survival. In contrast, there are small, but mostly separate, populations of early born and early projecting neurons within the matrix compartment. Quantitative analysis of these two distinct populations suggests that while early projection neurons within the matrix are spared, the early born matrix neurons lacking an early nigral projection undergo significant cell death. This proposal is further supported by the observation that the percentage of early born neurons in both the patch and matrix compartments that also have an early nigral projection increases from postnatal day 2 to 17. This finding suggests that among the early born striatal neurons in both compartments, those that do not project to the nigra selectively die during the cell death period. Together these results support the hypothesis that completion of an early projection to the substantia nigra gives neurons an advantage for surviving the cell death period.
Patterns of connectivity in the cat sensory‐motor cortex: A light and electron microscope analysis of the projection arising from area 3a
Authors: Porter Linda L. 
Published: January 2005

AbstractThrough its complex network of interconnections, each of the functionally specialized subdivisions in the cat primary somatosensory cortex may provide the motor cortex with different input and thus play a unique role in motor behavior. Areas 2 and 3a receive separate peripheral information. Cells in both regions project directly to the cat motor cortex but are thought to target different populations of neurons. In this study the morphology and distribution patterns of the area 3a projection to the motor cortex were compared to previous findings on the projection from area 2. Also, details of the projection from area 3a to area 2 were studied. Injections of Phaseolus vulgaris leucoagglutinin were made into area 3a and fixed brain tissue was processed for immunohistochemical staining of this anterograde tracer. Tissue was examined with the light microscope to determine the patterns of the 3a projections to area 2 and motor cortex, area 4. Axons arising from cells in area 3a terminated in multiple column‐like clusters in both motor cortex and area 2. The small number of cells labeled at the injection sites suggested that multiple foci of the 3a fibers are formed by collateral axonal branches of the same neurons. The topography of the projection from area 3a to the motor cortex was more clearly denned than that from area 3a to area 2. Electron microscope analysis determined the laminar distribution and types of synapses formed between area 3a efferents and their target neurons. A high proportion of synapses was found in layer III in both target regions. However, unlike in area 4, labeled terminals were sparse in laminae I and II of area 2. Axospinous synapses were slightly more numerous than axodendritic synapses, but both were distributed similarly throughout the thickness of the cortex. In area 2 the axospinous synapses accounted for 63% of synapses and in area 4 for 57% of synapses. No axosomatic synapses were detected.
Developmental alterations in nociceptive threshold, immunoreactive calcitonin gene‐related peptide and substance P, and fluoride‐resistant acid phosphatase in neonatally capsaicin‐treated rats
Authors: Hammond Donna L. , Ruda M. A. 
Published: January 2005

AbstractThis study examined the effect of neonatal administration of capsaicin on nociceptive threshold and the distribution of calcitonin gene‐related peptide (CGRP), substance P (SP), and fluoride‐resistant acid phosphatase (FRAP) in the dorsal horn of the spinal cord during the course of development (10 days to 12 weeks of age) in the rat. As early as 10 days of age, CGRP‐like immunoreactivity was reduced in laminae I, II, and V, as well as in the bundles of fibers situated dorsal and ventral to the central canal. However, beginning on or about 6 weeks of age, the density of CGRP‐like immunoreactivity in the superficial laminae and in the bundles dorsal and ventral to the central canal increased. Moreover, thick, nonvaricose CGRP‐like immunoreactive fibers appeared in laminae III and IV. These recurring fibers were of primary afferent origin as demonstrated by their disappearance after multiple, unilateral rhizotomies. A similar age‐dependent alteration in the density of FRAP activity was also observed. Although virtually absent at 10 days of age after neonatal administration of capsaicin, the density of FRAP activity increased in lamina II by 8 weeks of age. This activity disappeared after multiple, unilateral rhizotomies, indicating that the FRAP activity that reappeared was of primary afferent origin. Neonatal administration of capsaicin also reduced the density of SP‐like immunoreactivity in the dorsal horn as early as 10 days of age, although the density of SP‐like immunoreactivity showed some recovery after 6 weeks of age. However, unlike CGRP‐like immunoreactivity or FRAP activity, the density of SP‐like immunoreactivity in capsaicin‐treated rats was not detectably altered by multiple, unilateral rhizotomies, indicating that it originated principally from intrinsic dorsal horn neurons. Age‐dependent alterations in both thermal and mechanical, but not chemical, nociceptive thresholds were also observed in these same animals. Thus, tail flick latency, hot plate latency, and paw withdrawal threshold were maximally increased at 6 weeks of age, after which time thresholds declined to vehicle‐treated values. In contrast, capsaicin‐treated animals were uniformly insensitive to ophthalmic administration of capsaicin. The correspondence between developmental alterations in CGRP‐like immunoreactivity or FRAP activity and in thermal and mechanical nociceptive thresholds is suggestive of a role of CGRP‐ or FRAP‐containing primary afferents in thermal and mechanical nociception.
Organization of callosal connections in the visual cortex of the rabbit following neonatal enucleation, dark rearing, and strobe rearing
Authors: Grigonis Antony M. , Murphy E. Hazel 
Published: January 2005

AbstractThe organization of visual callosal projections was studied in (1) normal adult rabbits; (2) adult rabbits which had undergone monocular enucleation (ME) or binocular enucleation (BE) at birth; and (3) adult rabbits which had been deprived of normal visual experience during development by dark rearing (DR) or strobe rearing (SR). Previously published observations (Murphy and Grigonis, Behav Brain Res 30:151, 1988) on callosal organization in adult rabbits in which retinal ganglion cell activity was eliminated during development by intraocular tetrodotoxin (TTX) injections, are also summarized for comparison with these data.The tangential extent of the callosal cell zone was significantly larger than normal in DR, TTX, and ME rabbits, was unchanged in BE rabbits, and was significantly reduced in SR rabbits. An analysis of the laminar distribution of the callosal cells revealed a significant increase in the percentage of callosal cells in lamina IV in ME, DR, and TTX animals. Measurements of density of callosal cells showed a significant increase in the density of the callosal projection in ME and SR rabbits and a decrease in density in BE rabbits compared with normal.The data suggest that the mechanisms involved in the development of the tangential and laminar organization of the callosal cell zone are different. In addition, the data suggest that the mechanisms involved in the maintenance of callosal projections are different from the mechanisms involved in the elimination of callosal projections during development.The effects of these developmental manipulations on callosal organization in other mammals are reviewed and compared with the effects in rabbits. The data suggest that species differences in the degree of maturity of the visual system at birth and in the extent of callosal development at the time of eye opening, may underlie species differences in the effects of these manipulations on the organization of visual callosal projections during development.