Neuroscience
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Modern westernized diet is a major risk factor associated with the current obesity epidemic. To study the effects of dietary choices of Western societies, the cafeteria diet has been validated as a preclinical model of obesity. We aimed to investigate the behavioral and metabolic alterations induced by a cafeteria diet on gene expression and neurotransmitter contents involved in neural plasticity and reward processing. ⋯ The cafeteria diet increased BDNF expression in the dorsal striatum (DS), and norepinephrine, 5-HT, TrkB, CREB, and Dnmt3A levels in the hippocampus. Additionally, multiple regression analysis showed that accumbal DOPAC and BDNF mRNA levels were robustly predicted by hyperphagia, fat mass accumulation, and body weight gain only in the cafeteria group. Overall, cafeteria diet-induced hyperphagia could lead to alterations in hedonic and motivational control of food intake through changes in dopamine metabolism and BDNF signaling in the nucleus accumbens and the DS.
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Our previous studies revealed that miR-34a suppresses autophagy in the ageing cochlea, which correlates with cochlear hair cell loss and age-related hearing loss (AHL). However, the mechanisms underlying miR-34a regulation of autophagy in the cochlea remain unclear. Here, we show that nuclear translocation of transcription factor EB (TFEB), a master regulator of autophagy, was regulated by miR-34a in HEI-OC1 cells. ⋯ Long-term supplementation with rapamycin attenuated outer hair cells (OHCs) and inner hair cell synaptic ribbons, and delayed AHL in C57BL/6 mice. Most importantly, rapamycin partially restored TFEB's nuclear localization and autophagic flux in OHCs of the ageing cochlea. These findings open new avenues for protection against AHL through miR-34a/ATG9a/TFEB modulation of autophagy.
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In early psychosis there are alterations in the static functional interaction between the salience network (SN) and higher-order cognitive networks. It is unclear whether these changes extend to the dynamic functional connectivity (dFC) of the SN, and whether the dFC between the SN and low-order networks (e.g., sensory networks) is affected. This study examined the temporal properties of the functional connectivity of the SN in individuals with early psychosis. ⋯ We found compared with the HC, in the FES and CHR groups the bilateral AI and ACC showed less variability in dFC with regions in the visual network; the variability between the ACC and visual regions in the FES group was less than that of the CHR; and in the FES and CHR groups the variability in dFC was higher between the right AI and the left precuneus (a core region of the default mode network). This study confirmed abnormality of dynamic functional interaction between the SN and the DMN in psychosis. More importantly, the disruption of communication between the SN and the lower-order brain network is another important aspect of the neural basis of psychosis.
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The nociceptive withdrawal reflex (NWR) is a behavioral response to protect the body from noxious stimuli. The spatial characteristics of the stimulus modulate the reflex response to prevent damage to the affected tissue. Interneurons in the deep dorsal horn in the spinal cord encode the relationship between stimulus characteristics and the magnitude of the NWR and are also likely integrating spatial information of the nociceptive stimulus. ⋯ In contrast, the NWR recorded during the attention task did not differ from baseline. These results further support that the spinal NWR pathway is under descending control which can be modulated by cognitive processes. The NWRs recorded over both proximal and distal muscles were similarly affected by the tasks, suggesting that the descending control affects the lower leg spinal system, with no discrimination between spinal segments.
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Accurate and efficient non-rigid registration is important to investigate neural mechanisms in multi-session two-photon (2p) imaging across a few days. The 2p imaging recordings from different sessions usually possess certain complex misalignment or huge data variance due to relocation errors during experimental operations or brain recovery. Most of the reported neural image registration tools were able to solve the registration problem in the same session with small deformation. ⋯ In this study, we report the development of a non-rigid registration method for 2p imaging in mice based on image triangulation and piecewise affine transformation (TPAT) technologies. The TPAT method supported both automatic and semi-automatic operation types, and both showed great performance in the benchmark test of non-rigid neural image registration. The proposed method constitutes a step forward in promoting and accelerating discoveries from multi-session 2p imaging research.