Neuroscience
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Efr3a has been found to be involved in the functional maintenance and structural degeneration of sensory and motor nervous tissues. Our previous data have suggested that Efr3a may be associated with the initiation of the degeneration of spiral ganglion neurons (SGNs). In this study, we used Efr3a knockdown (Efr3a KD) and Efr3a overexpression (Efr3a OE) mice to determine the role of Efr3a in age-related hearing loss. ⋯ As indicated by the density of SGNs in the upper basal turn, the Efr3a OE mice displayed earlier and more severe degeneration than the KD mice. In addition, the p-Akt levels in the cochlear spiral ganglions were higher in adult Efr3a KD mice than in WT and OE mice, although there was no difference in Akt expression among the three groups. Our study suggests that down-regulation of Efr3a might improve hearing function and alleviate the degeneration of SGNs in an early stage of senescence, probably via enhancing the basal expression of activated Akt.
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A single exposure to amphetamine induces neurochemical sensitization in striatal areas. The neuropeptide angiotensin II, through AT1 receptors (AT1-R) activation, is involved in these responses. However, amphetamine-induced alterations can be extended to extra-striatal areas involved in blood pressure control and their physiological outcomes. ⋯ Meanwhile, no differences were found neither in CeAmy nor A1. Sensitized blood pressure response was observed as sustained changes in mean arterial pressure and was effectively prevented by AT1-R blockade. Our results extend AT1-R role in amphetamine-induced sensitization over noradrenergic nuclei and their cardiovascular output.
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The prefrontal cortex is essential for executive functions such as decision-making and planning. There is also accumulating evidence that it is important for the modulation of pain. In this study, we investigated a possible role of prefrontal cortical calcium-independent phospholipase A2 (iPLA2) in antinociception induced by the norepinephrine reuptake inhibitor (NRI) and tetracyclic (tricyclic) antidepressant, maprotiline. ⋯ These changes were not observed in maprotiline-treated mice that received iPLA2 antisense oligonucleotide to the prefrontal cortex. Metabolites of DHA and EPA may help to strengthen a known supraspinal antinociceptive pathway from the prefrontal cortex to the periaqueductal gray. Together, results indicate a role of prefrontal cortical iPLA2 and its enzymatic products in the antinociceptive effect of maprotiline.
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Randomized Controlled Trial
Increased functional connectivity one week after motor learning and tDCS in stroke patients.
Recent studies using resting-state functional magnetic resonance imaging (rs-fMRI) demonstrated that changes in functional connectivity (FC) after stroke correlate with recovery. The aim of this study was to explore whether combining motor learning to dual transcranial direct current stimulation (dual-tDCS, applied over both primary motor cortices (M1)) modulated FC in stroke patients. Twenty-two chronic hemiparetic stroke patients participated in a baseline rs-fMRI session. ⋯ At baseline and one week after sham, the strongest FC was observed between the M1 and dorsal premotor cortex (PMd) of the undamaged hemisphere. In contrast, one week after dual-tDCS, the strongest FC was found between the M1 and PMd of the damaged hemisphere. Thus, a single session of dual-tDCS combined with motor skill learning increases FC in the somatomotor network of chronic stroke patients for one week.
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In the vertebrate retina, horizontal cells (HCs) reveal homologous coupling by gap junctions (gj), which are thought to consist of different connexins (Cx). However, recent studies in mouse, rabbit and zebrafish retina indicate that individual HCs express more than one connexin. To provide further insights into the composition of gj connecting HCs and to determine whether HCs express multiple connexins, we examined the molecular identity and distribution of gj between HCs of the carp retina. ⋯ Furthermore, using single-cell RT-PCR, all four connexins were detected in different subtypes of HCs, suggesting overlapping expression patterns. Thus, the composition of gj mediating homologous coupling between subtypes of carp HCs appears to be more complex than expected. Moreover, BLAST searches of the preliminary carp genome, using novel sequences as query, suggest that most of the analyzed connexin genes are duplicated in carp.