Neuroscience
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In mice, 249 putative members of the superfamily of EF-hand domain Ca(2+)-binding proteins, manifesting great diversity in structure, cellular localization and functions have been identified. Three members in particular, namely, calbindin-D28K, calretinin and parvalbumin, are widely used as markers for specific neuronal subpopulations in different regions of the brain. The aim of the present study was to compile a comprehensive atlas of the gene-expression profiles of the entire EF-hand gene superfamily in the murine brain. ⋯ The expression profiles of four family-members, namely hippocalcin-like 4, neurocalcin-δ, plastin 3 and tescalcin, that have not been hitherto reported, at either the mRNA (in-situ-hybridization) or the protein (immunohistochemical) levels, are now presented for the first time. The fruit of our analysis is a document in which the gene-expression profiles of all members of the EF-hand family genes are compared, and in which future possible neuronal markers for specific cells/brain areas are identified. The assembled information could afford functional clues to investigators, conducive to further experimental pursuit.
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The medial parabrachial nucleus (MPB) and external part of the medial parabrachial nucleus (MPBE) relay gustatory, oral mechanosensory and other visceral information in the rat brain and reportedly project not only to the parvicellular part of the posteromedial ventral thalamic nucleus (VPMpc) but also to the ventrocaudal part of the intralaminar thalamic nuclei. Generally, the intralaminar thalamic nuclei project topographically to the caudate putamen (CPu); however, it is unclear where the ventrocaudal part of the intralaminar thalamic nuclei projects within the CPu. Thus, we visualized neural pathways from the MPB and MPBE to the CPu via the ventrocaudal part of the intralaminar thalamic nuclei using an anterograde tracer, biotinylated dextran amine, and a retrograde tracer, cholera toxin B subunit. ⋯ Further, we found that the VPMpc rather projected to the interstitial nucleus of the posterior limb of the anterior commissure than the CPu. The ventral part of the CPu is reported to be involved in jaw movement as well as food and water intake functions. Therefore, these parabrachio-thalamo-striatal pathways that we demonstrated here suggest that gustatory and oral mechanosensory information affects feeding behavior within the ventral part of the CPu.
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Neuropathic pain is a severe clinical problem, often appearing as a co-symptom of many diseases or manifesting as a result of damage to the nervous system. Many drugs and agents are currently used for the treatment of neuropathic pain, such as tricyclic antidepressants (TCAs). The aims of this paper were to test the effects of two classic TCAs, doxepin and amitriptyline, in naïve animals and in a model of neuropathic pain and to determine the role of cytokine activation in the effects of these drugs. ⋯ Allodynia and hyperalgesia induced in naïve animals by amitriptyline and doxepin may be associated with an increase in the levels of pronociceptive cytokines resulting from 5-HT3-induced hypersensitivity. Our results provide new and important information about the possible side effects of antidepressants. Further investigation of these mechanisms may help to guide decisions about the use of classic TCAs for therapy.
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Increasing evidence has suggested that microglia dysfunction plays an important role in the pathogenesis of depression. Both classical activation (M1 activation) and alternative activation (M2 activation) may be involved in the process. M1-activated microglia secrete various pro-inflammatory cytokines and neurotoxic mediators, which may contribute to the development of depression, while M2-activated microglia promote tissue reconstruction by releasing anti-inflammatory cytokines involved in the process of depression. ⋯ The indexes of activation were measured by real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA) and Western blot. The present results showed that both fluoxetine and S-citalopram significantly down-regulated the indexes of M1 activation and up-regulated the M2 activation indexes on mRNA and protein levels either in cell line or primary cells. Taken together, the results suggested that fluoxetine and S-citalopram modulated the immune system by inhibiting M1 activation and by improving M2 activation of microglia and that the immune system modulation may partially mediate the therapeutic effects of antidepressant drugs-SSRIs.
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The present study investigated the vestibulospinal system which originates from the spinal vestibular nucleus (SpVe) with both retrograde and anterograde tracer injections. We found that fluoro-gold (FG) labeled neurons were found bilaterally with a contralateral predominance after FG injections into the upper lumbar cord. Anterogradely labeled fibers from the rostral SpVe traveled in the medial part of the ventral funiculus ipsilaterally and the dorsolateral funiculus bilaterally in the cervical cord. ⋯ They mainly terminated in laminae 3-8 and 10 contralaterally. The present study is the first to describe the termination of vestibulospinal fibers arising from the SpVe in the spinal cord. It will lay the anatomical foundation for those who investigate the physiological role of vestibulospinal fibers and potentially target these fibers during rehabilitation after stroke, spinal cord injury, or vestibular organ injury.