Neuroscience
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Sensory substitution refers to the concept of feeding information to the brain via an atypical sensory pathway. We here examined the degree to which participants (deaf and hard of hearing) can learn to identify sounds that are algorithmically translated into spatiotemporal patterns of vibration on the skin of the wrist. In a three-alternative forced choice task, participants could determine the identity of up to 95% and on average 70% of the stimuli simply by the spatial pattern of vibrations on the skin. ⋯ Participants answered whether the word was the same or different. With minimal difference pairs (distinguished by only one phoneme, such as "house" and "mouse"), the best performance was 83% (average of 62%), while with non-minimal pairs (such as "house" and "zip") the best performance was 100% (average of 70%). Collectively, these results demonstrate that participants are capable of using the channel of the skin to interpret auditory stimuli, opening the way for low-cost, wearable sensory substitution for the deaf and hard of hearing communities.
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Differences in the intrinsic properties of intralaminar thalamo-striatal neurons such as expressing low-threshold-spikes (LTS) or after hyperpolarizing potentials (AHPs) of different duration have been attributed to different maturation stages. However, two morphological types: "diffuse" and "bushy" have been described. Therefore, we explored whether electrophysiological differences persist in adult mice using whole cell recordings. ⋯ Both cell classes could fire in two modes: trains of single action potentials at depolarized potentials or high frequency bursts on top of LTS at more hyperpolarized potentials. LTS were probably generated by Cav3 calcium channels since they were blocked by the selective antagonist TTA-P2. About 11% of neurons with brief AHPs and 55% of neurons with prolonged AHPs do not show LTS and bursts, even when potassium currents are blocked.
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Exposure to stress activates glucocorticoid receptors in the brain and facilitates the onset of multitude psychiatric disorders. It has been shown that FK506 binding protein 51 (FKBP5) expression increases during glucocorticoid receptor (GR) activation in various brain regions including the medial prefrontal cortex (mPFC). FKBP5 knockout (KO) mice are reported to be resilient to stress, however, it remains uninvestigated whether FKBP5 loss affects neurotransmission and if so, what the functional consequences are. ⋯ We found that GR activation significantly decreased excitatory neurotransmission in the mPFC, which was completely abolished upon FKBP5 deletion, in consistent with behavioral resilience observed in FKBP5 KO mice. Even though FKBP5 loss has minimal impact on neural excitability, we found that FKBP5 deletion distorts the excitatory/inhibitory balance in the mPFC. Our study suggests that FKBP5 deficiency leads to the mPFC insensitive to GR activation and provides a neurophysiological explanation for how FKBP5 deficiency may mediate stress resilience.
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Exercise is a promising, cost-effective intervention to augment successful aging and neurorehabilitation. Decline of gray and white matter accompanies physiological aging and contributes to motor deficits in older adults. ⋯ This knowledge will allow us to develop more effective, personalized exercise protocols that meet individual needs, thereby increasing the utility of exercise strategies in clinical and non-clinical settings. Here, we review findings from studies that investigated neurophysiological and molecular changes associated with acute or long-term exercise in healthy, young adults and in healthy, postmenopausal women.
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Gold nanoparticles (GNP) have emerged as an alternative to biomaterials in biomedical applications. Research has clearly demonstrated the relative safety and low toxicity of these molecules. However, the possible neuroprotective effect of GNP on the central nervous system (CNS) and its relationship with neurological and psychiatric disorders remain unclear. ⋯ GNP also prevented EtOH-induced increase in superoxide dismutase and catalase activities, suggesting a modulatory role of GNP in enzymatic antioxidant defenses. Our results showed that GNP was able to modulate the disruption of cholinergic and oxidative homeostasis in the brain of zebrafish. These findings indicate for the first time that zebrafish is an interesting perspective to investigate nanoparticles against disorders related to alcohol abuse.