bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein kinase C‐delta in rat brain: Association with sensory neuronal hierarchies
Authors: Garcia Meredith M. , Cusick Catherine G. , Harlan Richard E. 
Published: January 2005

AbstractOriginally characterized as the calcium‐ and phospholipid‐dependent protein kinases, the protein kinases C include at least eight separate isoforms, some of which are calciumindependent and all of which are highly enriched in brain. Of the calcium‐independent isoforms, the delta subspecies of protein kinase C has the most restricted complement of lipid activators and substrate specificity, suggesting that it may have a unique role in cell signalling pathways. Using immunocytochemistry, we report that the distribution of protein kinase C‐δ immunoreactivity in rat brain is also restricted, being present in all sensory systems. Moreover, it is found in alternating hierarchies of sensory pathways: in all sensory systems except auditory, it is found in first‐ and third‐order neurons, while in the auditory system, it is found in second‐ and fourth‐order neurons. Thalamocortical systems are intensely immunoreactive, including barrel fields of the rat parietal cortex. Outside of sensory systems, protein kinase C‐δ is present in cerebellum within longitudinal stripes in Purkinje neurons, and in the caudateputamen, it appears to be associated with the striosome (patch) compartment. In contrast to all other protein kinase C isoforms, protein kinase C‐δ is absent from hippocampus. These findings suggest that protein kinase C‐δ may have a unique role in signal transduction in the central nervous system (CNS), especially in sensory systems. © 1993 Wiley‐Liss, Inc.
Degenerate hearing and sound localization in naked mole rats (Heterocephalus glaber), with an overview of central auditory structures
Authors: Heffner Rickye S. , Heffner Henry E. 
Published: January 2005

AbstractBehavioral tests of absolute sensitivity and sound localization in African naked mole rats show that, despite their communal social structure and large vocal repertoire, their hearing has degenerated much like that of other subterranean species. First, their ability to detect sound is limited, with their maximum sensitivity being only 35 dB (occurring at 4 kHz). Second, their high‐frequency hearing is severely limited, with their hearing range (at 60 dB sound pressure level [SPL]) extending from 65 Hz to only 12.8 kHz. Third, determination of the effect of duration on noise thresholds indicates that, compared with other animals, mole rats require a sound to be present for a much longer duration before reaching asymptotic threshold. Finally, they are unable consistently to localize sounds shorter than 400 ms and cannot accurately localize sounds of longer duration, raising the possibility that they are unable to use binaural locus cues. Thus, it seems that the essentially one‐dimensional burrow system of a subterranean habitat produces severe changes in hearing comparable to the changes in vision that result from the absence of light. To explore the relation between vision and sound‐localization acuity, retinal ganglion cell densities were determined. The results indicate that naked mole rats have a broad area of best (albeit poor) vision, with maximum acuity estimated at 44 cycles/degree. That mammals with wide fields of best vision have poorer sound‐localization acuity than those with narrower fields is consistent with the thesis that a major function of sound localization is to direct the gaze to the source of a sound. However, the fact that subterranean mammals have little use for vision in a lightless environment suggests that they represent an extreme case in this relationship and may explain the fact that, unlike surface‐dwelling mammals, they have virtually lost the ability to localize brief sounds. Finally, despite their very limited auditory abilities, the major brainstem auditory nuclei, although relatively small, appear to be present. © 1993 Wiley‐Liss, Inc.
Laterality of superior olive projections to the inferior colliculus in adult and developing ferret
Authors: Henkel Craig K. , Brunso‐Bechtold Judy K. 
Published: January 2005

AbstractThe laterality of projections from the lateral superior olivary nucleus (LSO) to the inferior colliculus was studied in adult and immature postnatal ferrets. In the adult ferret, large unilateral injections of horseradish peroxidase (HRP) in the inferior colliculus labeled about equal proportions of cells in the ipsilateral and contralateral lateral superior olivary nuclei. The contralateral labeled cells consistently were more densely labeled than those on the ipsilateral side. Double labeling experiments using fluorescent dyes indicated that only about 3% of LSO cells in the adult give rise to collaterals ending in the inferior colliculus on both sides. As expected, the distribution of labeled cells varied topographically in the LSO as a function of the injection site in the inferior colliculus. Dorsolateral inferior collicular injections labeled cells in the lateral limb of the LSO, whereas ventromedial injections labeled cells in the medial limb of the LSO. The proportion of ipsilateral and contralateral labeled cells also varied across the lateral‐medial axis of the LSO in some cases. A gradient in laterality was observed in these cases with the lateral limb of the LSO containing the highest proportion of contralateral labeled cells, and the medial limb, the highest proportion of ipsilateral labeled cells. Larger inferior collicular injections resulted in greater proportions of ipsilateral labeling in LSO than smaller injections. Finally, ipsilateral labeled cells tended to be in the marginal region of the LSO, whereas contralateral labeled cells were more common within the core region of the LSO, irrespective of the location along the lateral‐medial axis of LSO. The contralateral predominance of labeled cells, greater density of labeling in contralateral cells, different topographic distribution, and regional segregation of ipsilateral and contralateral labeled cells were typical of the LSO in ferret kits by birth, one month before the onset of hearing. Nevertheless, the relative proportion of ipsilateral and contralateral projection cells appears to change during postnatal development. © 1993 Wiley‐Liss, Inc.
Morphological and quantitative evaluation of olfactory bulb development in Xenopus after olfactory placode transplantation
Authors: Byrd Christine A. , Burd Gail D. 
Published: January 2005

AbstractWe found previously that the number of olfactory axons is correlated with the number of mitral/tufted cells (output neurons of the olfactory bulb) during normal larval development. To examine the significance of this quantitative relationship, we evaluated the effects of transplanting an extra olfactory placode on the development of the larval olfactory bulb. We found that the transplanted tissue retained the normal, pseudostratified, columnar appearance and had the same cell types as normal olfactory epithelium, and the olfactory bulbs had the same laminar organization as control bulbs. With gross examination of the olfactory bulb, the side innervated by the transplant appeared slightly larger than the contralateral side in animals analyzed at a young larval stage (stage 50) and in 2 of the 9 animals examined at late larval stages (57/58). Tissue sections and area measurements, however, revealed that the volume of the olfactory bulbs in animals with a transplant was not significantly different from control values.Our quantitative analysis also showed that in stage‐50 animals with a transplant, the total number of olfactory axons (in nerves from the transplanted and host olfactory organs) appeared to be greater than in control animals, but not to a statistically significant level. The number of mitral/tufted cells was not different from controls. In animals examined at stage 57/58, there was no differnce from controls in either the total number of olfactory axons, total number of mitral/tufted cells, or convergence ratio of olfactory axons onto mitral/tufted cells. Thus, in the late‐stage larvae, the quantitative relationship between olfactory axons and mitral/tufted cells was not altered by the experimental manipulation. These results suggest that the olfactory bulb can regulate the number of affernt fibers. © 1993 Wiley‐Liss, Inc.
Ventral subicular interaction with the hypothalamic paraventricular nucleus: Evidence for a relay in the bed nucleus of the stria terminalis
Authors: Cullinan William E. , Herman James P. , Watson Stanley J. 
Published: January 2005

AbstractThe axonal projections of the ventral subiculum to the bed nucleus of the stria terminalis (BST) were examined in the rat with the anterograde neuronal tracer Phaseolus vulgaris‐ leucoagglutinin (PHA‐L). Axons originating in the ventral subiculum coursed to the BST through either the fimbria‐fornix, or a pathway involving the stria terminalis via the amygdala. Ventral subicular axons gave rise to dense terminal networks that were preferentially distributed in medial and ventral subregions of the BST. The distribution of subicular fibers and terminals was examined in relation to BST neurons that project to the hypothalamic paraventricular nucleus (PVN). In these cases, discrete iontophoretic injections of the retrograde tracer Fluoro‐gold were made in the PVN, with PHA‐L delivered to the ipsilateral ventral subiculum. An immunocytochemical double‐labeling protocol was then employed for the simultaneous detection of PHA‐L and Fluoro‐gold, and provided light microscopic evidence for subicular input to PVN‐projecting cells located within the BST.In a second series of experiments, the γ‐amino butyric acid (GABA)ergic nature of the BST was examined by in situ hybridization histochemistry for detection of transcripts encoding GAD67 mRNA. The studies revealed that a high proportion of BST neurons express GAD67 transcripts. Also, experiments combining Fluoro‐gold tracing with GAD67 in situ hybridization suggested that a proportion of PVN‐projecting neurons in the BST are GABAergic. Taken together, the results of these sets of studies suggest that the inhibitory influences of the hippocampus on the PVN might be relayed through specific portions of the BST. These findings may have important implications for our understanding of the neural regulation of the hypothalamic‐pituitary‐adrenal axis. © 1993 Wiley‐Liss, Inc.
GABA‐ and glycine‐immunoreactive neurons in the spinal cord of the carp, Cyprinus carpio
Authors: Uematsu Kazumasa , Shirasaki Makiko , Storm‐Mathisen Jon 
Published: January 2005

Abstractγ‐Aminobutyric acid (GABA) and glycine are the two main inhibitory transmitter amino acids in the central nervous system of vertebrates. The distribution of cells containing GABA and glycine in the carp spinal cord was examined by using specific antisera raised against the two amino acids conjugated to bovine serum albumin. The immunoreaction on serial paraffin sections was visualized by a streptavidin‐biotin method. Both antisera gave highly specific labellings of cells. At least three types of GABA‐immunoreactive cells were found. They were small cells in the dorsal grey matter, various sized cells in the central and ventral grey, and some ependymal cells contacting the central canal. In addition, very small cells and neuropil structures in the dorsal horn were strongly immunoreactive to the GABA serum. Certain cells in the ventral horn have moderate numbers of labelled synaptic boutons on the perikarya, but very few GABA‐labelled terminals were found on putative motoneurons. The immunoreactive ependymal cells appeared to have a ventrolaterally directed axon. The glycine antiserum labelled small and intermediate cells in the dorsal grey, large, elongated cells in the median region, and varying sized cell sin the ventral grey. The numbers and density of immunoreactive cells and neuropil strucures in the ventral horn were fewer and lower than in GABA‐stained sections. The median large cells had a thick venrolateral process. The ventral intermediate cells were often found near putative motoneurons. Labelled synaptic boutons were present on most ventral cells including putative motoneurons and interneurons. Abundant distribution of cells immunoreactive to both antisera suggest important roles of both GABA and glycine as neurotransmitters for controlling swimming movements in teleosts. © 1993 Wiley‐Liss, Inc.
Intersegmental ascending interneurones controlling uropod movements of the crayfish Procambarus clarkii
Authors: Nagayama Toshiki , Isogai Yukihiro , Sato Motoaki , Hisada Mituhiko 
Published: January 2005

AbstractThe premotor effects of intersegmental ascending interneurones upon uropod motor neurones in the crayfish Procambarus clarkii (Girard) are examined with intracellular recording and staining techniques. We show that many ascending interneurones can affect the activity of the antagonistic opener and closer motor neurones in the terminal ganglion. Based upon soma position, ascending interneurones are divided into three groups of rostral, medial, and caudal interneurones. Twenty‐four ascending interneurones are characterized physiologically according to their inputs from the tailfan and their output effects on the uropod motor neurones of both sides. Each interneurone is identifiable as a unique individual by means of overall shape, soma position, number of main branches, the commissure in which primary neurites cross the midline, axon position in the 5th–6th abdominal connective and physiological responses. They are classified into six classes; coactivating, coinhibiting, reciprocally closing, reciprocally opening, variably effective, and not effective interneurones, according to their premotor effects on the uropod motor neurones. These ascending interneurones seem to act as multifunctional units conveying sensory information from the tailfan to the anterior abdominal ganglia and, at the same time, influencing the uropod motor pattern in the terminal abdominal ganglion. © 1993 Wiley‐Liss, Inc.
Striatal connections of the parietal association cortices in rhesus monkeys
Authors: Yeterian Edward H. , Pandya Deepak N. 
Published: January 2005

AbstractThe corticostriatal connections of the parietal association cortices were examined by the autoradiographic technique in rhesus monkeys. The results show that the rostral portion of the superior parietal lobule projects predominantly to the dorsal portion of the putamen, whereas the caudal portion of the superior parietal lobule and the cortex of the upper bank of the intraparietal sulcus have connections with the caudate nucleus as well as with the dorsal portion of the putamen. The medial parietal convexity cortex projects strongly to the caudate nucleus, and has less extensive projections to the putamen. In contrast, the medial parietal cortex within the caudal portion of the cingulate sulcus projects predominantly to the dorsal portion of the putamen, and has only minor connections with the caudate nucleus. The rostral portion of the inferior parietal lobule projects mainly to the ventral sector of the putamen, and has only minor connections with the caudate nucleus. The middle portion of the inferior parietal lobule has sizable projections to both the putamen and the caudate nucleus. The caudal portion of the inferior parietal lobule as well as the lower bank of the intraparietal sulcus project predominantly to the caudate nucleus, and have relatively minor connections with the putamen. The cortex of the parietal opercular region also shows a specific pattern of corticostriatal projections. Whereas the rostral portion projects exclusively to the ventral sector of the putamen, the caudal portion has connections to the caudate nucleus as well. Thus, it seems that parietostriatal projections show a differential topographic distribution; within both the superior and the inferior parietal region, as one progresses from rostral to caudal, there is a corresponding shift in the predominance of projections from the putamen to the caudate nucleus. In addition, with regard to the projections to the putamen, the superior parietal lobule is related mainly to the dorsal portion, and the inferior parietal lobule to the ventral portion. The striatal projections of the cortex of the caudal portion of the cingulate gyrus (corresponding in part to the supplementary sensory area) and of the rostral parietal opercular region (corresponding in part to the second somatosensory area) are directed almost exclusively to the dorsal and ventral sectors of the putamen, respectively. This pattern resembles that of the primary somatosensory cortex. The results are discussed with regard to the overall architectonic organization of the posterior parietal region. Possible functional aspects of parietostriatal connectivity are considered in the light of physiological and behavioral studies. © 1993 Wiley‐Liss, Inc.
Ultrastructural characteristics of enkephalin‐immunoreactive boutons and their postsynaptic targets in the shell and core of the nucleus accumbens of the rat
Authors: Meredith G. E. , Ingham C. A. , Voorn P. , Arbuthnott G. W. 
Published: January 2005

AbstractThe present study compared the ultrastructural morphology of enkephalin‐immunoreactive boutons and their postsynaptic targets in different territories of the nucleus accumbens in the rat. The synaptic bouton profiles were identified by antibodies directed against [leu5]enkephalin. Ninety‐five percent of the synaptic contacts were symmetric in configuration and the remaining 5% were asymmetric. Axosomatic contacts comprised 6% of all enkephalin‐immunoreactive junctions and were distributed equally in all parts of the nucleus. Most (76%) synaptic terminals contacted dendrites but they contacted proportionally fewer dendrites in the shell (71%) than in the core (78%). Moreover, enkephalin‐immunoreactive synaptic boutons in the shell (19%) and caudal enkephalin‐rich areas (17%) of the core contacted twice as many spines than in the remaining parts of the core (8.5%). In the core, long pallidum‐like dendrites were occasionally found ensheathed in enkephalin‐immunoreactive terminal boutons.We conclude that the differential arrangement of enkephalinergic contacts in the shell and core could have important functional consequences, especially when considered in relation to other known morphological and neurochemical differences between these regions. © 1993 Wiley‐Liss, Inc.
Localization of NADPH diaphorase activity in monoaminergic neurons of the rat brain
Authors: Johnson Mark D. , Ma Pokay M. 
Published: January 2005

AbstractNitric oxide has recently been implicated as a neurotransmitter, and may modulate synaptic transmission, cerebral blood flow, and neurotoxicity. NADPH diaphorase histochemistry has been shown to be a reliable marker for nitric oxide synthase, the enzyme that synthesizes nitric oxide, in the nervous system. Because monoaminergic neurons frequently contain co‐transmitters, we examined whether these cells also exhibit NADPH diaphorase activity. Frozen sections from postnatal and adult rat brains were stained for NADPH diaphorase activity and either serotonin‐like immunoreactivity or tyrosine hydroxylase‐like immunoreactivity. Numerous neurons in the mesopontine serotoninergic cell groups (including the caudal linear, dorsal, median, supralemniscal, and pontine raphe nuclei) contained both serotonin‐like immunoreactivity and NADPH diaphorase activity. Within the dorsal raphe nucleus, approximately 70% of the serotoninergic neurons in the medial subnuclei displayed NADPH diaphorase activity, while less than 10% of the serotoninergic neurons in the lateral subnuclei were doubly labeled. Retrograde labeling with fluorescent microspheres indicated that many raphe‐cortical neurons contained NADPH diaphorase activity. No NADPH diaphorase activity was detected in serotoninergic neurons in the medullary nuclei (including the raphe magnus, raphe pallidum, and raphe obscurus). Only a small proportion of tyrosine hydroxylase‐like immunoreactive neurons in the periaqueductal gray, rostral linear nucleus, and rostrtrodorsal ventral tegmental area contained NADPH diaphorase activity. Tyrosine hydroxylase‐like immunoreactive neurons in the substantia nigra, locus coeruleus, hypothalamus, olfactory bulb, and dorsal raphe nucleus did not contain detectable NADPH diaphorase activity. The observation that many mesopontine (but not medullary) serotoninergic neurons contain NADPH diaphorase activity suggests that these neurons may release both serotonin and nitric oxide. © Wiley‐Liss, Inc.
Ultrastructural localization and afferent sources of corticotropin‐releasing factor in the rat rostral ventrolateral medulla: Implications for central cardiovascular regulation
Authors: Milner Teresa A. , Reis D. J. , Pickel V. M. , Aicher S. A. , Giuliano R. 
Published: January 2005

AbstractWe investigated the ultrastructural localization, afferent sources, and arterial pressure effects of corticotropin‐releasing factor (CRF) in the nucleus reticularis rostroventrolateralis (RVL), a region of the ventrolateral medulla containing C1 adrenergic neurons and sympatho‐excitatory reticulospinal afferents to sympathetic preganglionic neurons. A polyclonal antibody, to CRF was localized in acrolein‐fixed sections through the rat RVL by the peroxidase–antiperoxidase (PAP) method. Light microscopy showed that 1–7 perikarya/30 μm section and numerous varicose processes contained CRF‐like immunoreactivity (CRF‐LI). By electron microscopy, CRF‐LI was most intensely localized to large (80–100 nm) dense‐core vesicles within numerous terminals and a few perikarya and large dendrites. Approximately half of the terminals containing CRF‐LI were in direct contact with unlabeled perikarya or dendrites; the remainder were in apposition to either unlabeled terminals or astrocytes. Most synaptic specializations were asymmetric synapses on small, unlabeled dendrites.To examine potential extrinsic sources of CRF‐containing terminals in the C1 area of the RVL, PAP immunocytochemical localization of CRF was combined with retrograde transport of wheat germ agglutinin‐conjugated horseradish peroxidase (WGA‐HRP). In all cases examined, a number of dually labeled neurons were found in the paraventricular nucleus (PVN) of the hypothalamus and a few dually labeled neurons were observed in the nuclei of the solitary tract; these labeled neurons were ipsilateral to the unilateral injection of WGA‐HRP into the C1 area. Fewer dually labeled perikarya were detected in the lateral hypothalamic area and the lateral parabrachial nuclei, ipsilateral to the WGA‐HRP injection.Additional physiological studies showed that bilateral microinjections of CRF into the C1 area of the RVL of urethane‐anesthetized rats elicited a dose‐related increase in arterial pressure. The results suggest that within the C1 area of the RVL, CRF released from terminals, arising predominantly from the PVN of the hypothalamus and probably from local neurons as well, may excite sympathoexcitatory reticulospinal neurons. © 1993 Wiley‐Liss, Inc.