Neuroscience
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Dementia is an increasing disorder, and Alzheimer's disease (AD) is the cause of 60% of all dementia cases. Despite all efforts, there is no cure for stopping dementia progression. ⋯ In addition to neuroinflammation suppression, psychedelics induce neuroplasticity by increasing Brain-derived neurotrophic factor (BDNF) levels through Sigma-1R stimulation. This review discussed the effects of psychedelics on AD from both neuroinflammatory and neuroplasticity standpoints.
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This study aimed to elucidate the spatial and temporal patterns of brain neural activity that are associated with cold and hot sensations. Participants (n = 20) sat in a controlled room with their eyes closed and received local thermal stimuli to the right fingers using a Peltier apparatus. The thermal stimuli were repeated 40 times using a paired-thermal stimulus paradigm, comprising a 15 s-reference stimulus (32 °C), followed by 10 s-conditioned stimuli (24 °C and 40 °C, cold and hot conditions, respectively), for which 15-channel electroencephalography (EEG) signals were continuously monitored. ⋯ The right precentral gyrus, precuneus, medial frontal gyrus, middle frontal gyrus, superior frontal gyrus, cuneus, cingulate gyrus, left precentral gyrus, middle occipital gyrus, and cingulate gyrus were activated in both cold and hot conditions. In most activated regions, EEG power temporal changes were observed across the frequency ranges and were different between the two conditions. These results may suggest that cold and hot sensations are processed through different temporal brain neural activity patterns in overlapping brain regions.
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There are various forms of stress including; physical, psychological and social stress. Exposure to physical stress can lead to physical sensations (e.g. hyperalgesia) and negative emotions including anxiety and depression in animals and humans. Recently, our studies in mice have shown that acute physical stress induced by the elevated open platform (EOP) can provoke long-lasting mechanical hypersensitivity. ⋯ Furthermore, we investigated projection-selective responses of the mediodorsal thalamus to the layer V ACC neurons. EOP exposure produced short-term depression in excitatory synaptic transmission on thalamo-ACC projections. These results suggest that the EOP stress provokes abnormal excitatory synaptic transmission in layer V pyramidal neurons of the ACC.
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The temporal order of propagation in the blood-oxygen-level-dependent (BOLD) infra-slow activity (ISA, 0.01-0.1 Hz) of functional magnetic resonance imaging (fMRI) can indicate the functional organization of the brain. While prior studies have revealed the temporal order of propagation of BOLD ISA during rest, how it emerges during cognitive tasks remains unclear. Furthermore, its differences between the gray and white matters at the whole-brain scale are unexplored. ⋯ This result differs from the previously reported propagation direction during rest that traveled from the visual and somatosensory cortices to the DMN, suggesting that the functional organization may change when performing cognitive tasks. In addition, the propagation in the white matter represented more complex patterns than that in the gray matter, exhibiting that the cingulum preceded DMN. Our results may help the understanding of how task performance alters the sensory-DMN propagation according of ISA.
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Internet gaming disorder (IGD) is increasingly recognized as a public concern for its adverse impacts on cognition and mental health. In IGD, the transition from goal-directed actions to habitual and eventually compulsive behaviors is accompanied by altered neural response within the dorsal anterior cingulate cortex (dACC), a critical region involved in conscious actions. However, the neurochemical profile of the dACC in IGD and its relationship with behavioral awareness remain poorly understood. ⋯ In an independent cohort of 107 participants, the positive association between awareness and dACC glutamate concentration was replicated. These findings suggest that reduced dACC glutamate in IGD may underlie diminished awareness of maladaptive habitual behaviors. Enhancing dACC neural excitability through neuromodulation or mindfulness training could represent a potential intervention to restore behavioral awareness.