Neuroscience
-
Human spatial manipulation ability is sensitive to high-altitude (HA) environment. The present study aimed to investigate the electrophysiological basis of spatial manipulation ability on adult immigrants with long-term HA exposure using the mental rotation (MR) task and the ERP approach. Toward this end, we explored the MR effect in individuals who immigrated to HA areas for three years compared with individuals who lived in low altitude areas. ⋯ The ERP component analysis further indicated that the rotation-related negativity (RRN) amplitude was highly corresponding to the MR effect in each group, the RRN amplitude was significantly larger in the HA group than the low-altitude group related to each rotation angle condition. The brain topographical map further showed that only the right hemisphere regions instead of the bilateral hemisphere regions involved into the MR effect in the HA group, which was different to the low-altitude group. Together, these findings might collectively suggest that the mental resource was insufficient as a result of HA exposure which can be reflected on the RRN amplitude, which may help understanding the neural basis of spatial ability change from the long-term HA exposure.
-
P2X2 receptors are ligand-gated cation channels activated by extracellular ATP that modulate neural transmission in various neuronal systems. Although the function and distribution of P2X2 receptors in the cochlea portion of the inner ear are well established, their physiological role in the vestibular portion is still not understood. Therefore, we investigated P2X2 receptor localization in the peripheral vestibular portion, and assessed their physiological function in vivo using P2X2 receptor knock out (P2X2-KO) mice. ⋯ VOR gain in P2X2-KO mice was significantly reduced, with no decrease in the optokinetic response. In conclusion, we showed that P2X2 receptors are mainly localized in the supporting cells of the vestibular inner ear, and the loss of P2X2 receptors causes mild vestibular dysfunction. Taken together, our findings suggest that the P2X2 receptor plays a modulatory role in vestibular function.
-
Traumatic brain injury (TBI) results in mitochondrial dysfunction and induction of lipid peroxidation (LP). Lipid peroxidation-derived neurotoxic aldehydes such as 4-HNE and acrolein bind to mitochondrial proteins, inducing additional oxidative damage and further exacerbating mitochondrial dysfunction and LP. Mitochondria are heterogeneous, consisting of both synaptic and non-synaptic populations. ⋯ By 24 h, synaptic respiration is significantly impaired compared to synaptic sham, whereas non-synaptic respiration does not decline significantly until 48 h. Decreases in respiration are associated with increases in oxidative damage to synaptic and non-synaptic mitochondrial proteins at 48 h and 72 h, respectively. These results indicate that the therapeutic window for mitochondria-targeted pharmacological neuroprotectants to prevent respiratory dysfunction is shorter for the more vulnerable synaptic mitochondria than for the non-synaptic population.
-
Prior research with a rat model of behavioral therapy [i.e., effort-based reward (EBR) contingency training] suggests that strengthened associations between physical effort and desired outcomes enhance neurobiological indices of resilience. In the current study, male and female Long-Evans rats were exposed to either six weeks of EBR training or noncontingent training prior to 10 days of exposure to chronic unpredictable stress (CUS). Subsequently, all animals were exposed to a problem-solving task and then trained in a spatial learning/foraging task, the Dry Land Maze (DLM). ⋯ Contingency training decreased BDNF-immunoreactivity (ir) in the hippocampus CA1 and lateral habenula, implicating differential neuroplasticity responses in the training groups. Further, coordinated fos-ir activation in areas associated with emotional resilience (i.e., motivation-regulation) was observed in contingent-trained animals. In sum, the current findings confirm that behavioral training is associated with neurobiological markers of emotional resilience; however, further assessments are necessary to more accurately determine the therapeutic potential for the EBR contingency training model.
-
Strong evidence exists that Toll-like receptor (TLR)-mediated effects on microglia functional states can promote ictogenesis and epileptogenesis. So far, research has focused on the role of high-mobility group box protein 1 as an activator of TLRs. However, the development of targeting strategies might need to consider a role of additional receptor ligands. ⋯ The pronounced impact on the response to subsequent stimulations gives first evidence that genetic HSPA1A upregulation may also contribute to epileptogenesis. Thus, strategies inhibiting hsp70 or its expression might be of interest for prevention of seizures and epilepsy. However, conclusions about a putative pro-epileptogenic effect of hsp70 require further investigations in models with development of spontaneous recurrent seizures.