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Comp Neurol (comp + neurol)

Distribution by Scientific Domains
Life Sciences100%

Kinds of Comp Neurol

  • j comp neurol
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    Selected Abstracts

    Evidence for neural stem cells in the medaka optic tectum proliferation zones,

    DEVELOPMENTAL NEUROBIOLOGY, Issue 10 2010
    Alessandro Alunni
    Abstract Few adult neural stem cells have been characterized in vertebrates. Although teleosts continually generate new neurons in many regions of the brain after embryogenesis, only two types of neural stem cells (NSCs) have been reported in zebrafish: glial cells in the forebrain resembling mammalian NSCs, and neuroepithelial cells in the cerebellum. Here, following our previous studies on dividing progenitors (Nguyen et al. [1999]: J Comp Neurol 413:385,404.), we further evidenced NSCs in the optic tectum (OT) of juvenile and adult in the medaka, Oryzias latipes. To detect very slowly cycling progenitors, we did not use the commonly used BrdU/PCNA protocol, in which PCNA may not be present during a transiently quiescent state. Instead, we report the optimizations of several protocols involving long subsequent incubations with two thymidine analogs (IdU and CldU) interspaced with long chase times between incubations. These protocols allowed us to discriminate and localize fast and slow cycling cells in OT of juvenile and adult in the medaka. Furthermore, we showed that adult OT progenitors are not glia, as they express neither brain lipid-binding protein (BLBP) nor glial fibrillary acidic protein (GFAP). We also showed that expression of pluripotency-associated markers (Sox2, Musashi1 and Bmi1) colocalized with OT progenitors. Finally, we described the spatio-temporally ordered population of NSCs and progenitors in the medaka OT. Hence, the medaka appears as an invaluable model for studying neural progenitors that will open the way to further exciting comparative studies of neural stem cells in vertebrates. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 693,713, 2010 [source]

    Evidence regarding the integrity of the posterior medial lateral suprasylvian visual area in the cat

    THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 16 2010
    Helen Sherk
    Abstract Among the areas of lateral suprasylvian visual cortex in cats defined by Palmer et al. (J Comp Neurol [1978] 177:237,256), PMLS (posterior lateral suprasylvian area) has been the most studied. Although PMLS has strong and well-documented connections with area 17, it is unclear whether these connections extend to its upper visual field representation. We asked what cortical areas send input to the upper field representation in PMLS by making tracer injections in areas 17, 19, and posterior suprasylvian cortex. Tracer injections made in area 17's upper field representation in 15 cats failed to label the corresponding region in PMLS. Instead, they showed that area 17 is strongly connected with the posterior bank of the posterior suprasylvian sulcus (pSS), a region attributed by Palmer et al. to area 21a. Injections in area 19 had the same outcome. We consider this posterior upper field representation plus the lower field representation in PMLS to belong to a single area, LS (lateral suprasylvian visual area). Our data suggest that the upper field representation in PMLS belongs to a different area, most likely AMLS (anterior medial lateral suprasylvian area). J. Comp. Neurol. 518:3343,3358, 2010. © 2010 Wiley-Liss, Inc. [source]

    Genoarchitectonic profile of developing nuclear groups in the chicken pretectum

    THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 4 2009
    J.L. Ferran
    Abstract Earlier results on molecularly coded progenitor domains in the chicken pretectum revealed an anteroposterior subdivision of the pretectum in precommissural (PcP), juxtacommissural (JcP), and commissural (CoP) histogenetic areas, each specified differentially (Ferran et al. [2007] J Comp Neurol 505:379,403). Here we examined the nuclei derived from these areas with regard to characteristic gene expression patterns and gradual histogenesis (eventually, migration patterns). We sought a genoarchitectonic schema of the avian pretectum within the prosomeric model of the vertebrate forebrain (Puelles and Rubenstein [2003] Trends Neurosci 26:469,476; Puelles et al. [2007] San Diego: Academic Press). Transcription-factor gene markers were used to selectively map derivatives of the three pretectal histogenetic domains: Pax7 and Pax6 (CoP); FoxP1 and Six3 (JcP); and FoxP2, Ebf1, and Bhlhb4 (PcP). The combination of this genoarchitectonic information with additional data on Lim1, Tal2, and Nbea mRNA expression and other chemoarchitectonic results allowed unambiguous characterization of some 30 pretectal nuclei. Apart from grouping them as derivatives of the three early anteroposterior domains, we also assigned them to postulated dorsoventral subdomains (Ferran et al. [2007]). Several previously unknown neuronal populations were detected, thus expanding the list of pretectal structures, and we corrected some apparently confused concepts in the earlier literature. The composite gene expression map represents a substantial advance in anatomical and embryological knowledge of the avian pretectum. Many nuclear primordia can be recognized long before the mature differentiated state of the pretectum is achieved. This study provides fundamental notions for ultimate scientific study of the specification and regionalization processes building up this brain area, both in birds and other vertebrates. J. Comp. Neurol. 517:405,451, 2009. © 2009 Wiley-Liss, Inc. [source]

    Editor's remarks: Chemotopic odorant coding in a mammalian olfactory system, Johnson et al., J Comp Neurol 503:1,34,

    THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2007
    Thomas E. Finger Associate Editor
    No abstract is available for this article. [source]

    Neurotrophic effects of GM1 ganglioside and electrical stimulation on cochlear spiral ganglion neurons in cats deafened as neonates

    THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 6 2007
    Patricia A. Leake
    Abstract Previous studies have shown that electrical stimulation of the cochlea by a cochlear implant promotes increased survival of spiral ganglion (SG) neurons in animals deafened early in life (Leake et al. [1999] J Comp Neurol 412:543,562). However, electrical stimulation only partially prevents SG degeneration after deafening and other neurotrophic agents that may be used along with an implant are of great interest. GM1 ganglioside is a glycosphingolipid that has been reported to be beneficial in treating stroke, spinal cord injuries, and Alzheimer's disease. GM1 activates trkB signaling and potentiates neurotrophins, and exogenous administration of GM1 has been shown to reduce SG degeneration after hearing loss. In the present study, animals were deafened as neonates and received daily injections of GM1, beginning either at birth or after animals were deafened and continuing until the time of cochlear implantation. GM1-treated and deafened control groups were examined at 7,8 weeks of age; additional GM1 and no-GM1 deafened control groups received a cochlear implant at 7,8 weeks of age and at least 6 months of unilateral electrical stimulation. Electrical stimulation elicited a significant trophic effect in both the GM1 group and the no-GM1 group as compared to the contralateral, nonstimulated ears. The results also demonstrated a modest initial improvement in SG density with GM1 treatment, which was maintained by and additive with the trophic effect of subsequent electrical stimulation. However, in the deafened ears contralateral to the implant SG soma size was severely reduced several months after withdrawal of GM1 in the absence of electrical activation. J. Comp. Neurol. 501:837,853, 2007. © 2007 Wiley-Liss, Inc. [source]

    Projections from bed nuclei of the stria terminalis, posterior division: Implications for cerebral hemisphere regulation of defensive and reproductive behaviors

    THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 4 2004
    Hong-Wei Dong
    Abstract The posterior division of the bed nuclei of the stria terminalis has three major nuclei: principal, interfascicular, and transverse, which receive topographically ordered inputs from the medial amygdalar nucleus. The overall pattern of axonal projections from each nucleus was determined in male rats with the Phaseolus vulgaris -leucoagglutinin method. Together, these nuclei project topographically back to the medial amygdalar nucleus, to the adjacent lateral septal nucleus, to the nucleus accumbens and substantia innominata, to hypothalamic parts of the behavior control column, and to the hypothalamic periventricular region, which controls patterned neuroendocrine and autonomic responses. The principal nucleus preferentially innervates septal and hypothalamic regions that control reproductive behavior and visceromotor responses, confirming a similar analysis by Gu et al. (J Comp Neurol [2003] 460:542,562). In contrast, the interfascicular and transverse nuclei differentially innervate septal and hypothalamic regions that control defensive as well as reproductive behaviors. In addition, the transverse nucleus projects significantly to midbrain parts of the behavior control column concerned with foraging/exploratory behavior. All three posterior division nuclei also project to thalamocortical feedback loops (by means of the nucleus reuniens and paraventricular nucleus). These structural data may be interpreted to suggest that the bed nuclei posterior division forms part (pallidal) of a corticostriatopallidal system involved in controlling two major classes of social (defensive and reproductive) behavior. J. Comp. Neurol. 471:396,433, 2004. © 2004 Wiley-Liss, Inc. [source]