Neuroscience
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The suprachiasmatic nucleus (SCN) is a network of neural oscillators that program daily rhythms in mammalian behavior and physiology. Over the last decade much has been learned about how SCN clock neurons coordinate together in time and space to form a cohesive population. ⋯ Here we review the current understanding of communication among SCN clock cells and highlight a collection of formal assays where changes in SCN interactions provide for plasticity in the waveform of circadian rhythms in behavior. Future studies that pair analytical behavioral assays with modern neuroscience techniques have the potential to provide deeper insight into SCN circuit mechanisms.
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In order to decipher the disease etiology, progression and treatment of multifactorial human brain diseases we utilize a host of different experimental models. Recently, patient-derived human dermal fibroblast (HDF) cultures have re-emerged as promising in vitro functional system for examining various cellular, molecular, metabolic and (patho)physiological states and traits of psychiatric disorders. ⋯ These reports unequivocally prove that signal transduction, redox homeostasis, circadian rhythms and gene*environment (G*E) interactions are all amenable for assessment by the HDF model. Furthermore, the reported findings suggest that this underutilized patient biomaterial, combined with modern molecular biology techniques, may have both diagnostic and prognostic value, including prediction of response to therapeutic agents.
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This cross-sectional study evaluated event-related potentials (ERPs) across three groups: naïve, novice, and experienced meditators as potential physiological markers of mindfulness meditation competence. ⋯ Meditators had stronger P3 amplitude responses to target tones when instructed to attend to the tones, and a greater attenuation of P3 amplitudes when instructed to ignore the same tones during the Breath Counting task. This study introduces the idea of identifying ERP markers as a means of measuring mindfulness meditation competence, and results suggest this may be a valid approach. This information has the potential to improve mindfulness meditation interventions by allowing objective assessment of mindfulness meditation quality.
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In violent video games, players engage in virtual aggressive behaviors. Exposure to virtual aggressive behavior induces short-term changes in players' behavior. In a previous study, a violence-related version of the racing game "Carmageddon TDR2000" increased aggressive affects, cognitions, and behaviors compared to its non-violence-related version. ⋯ The FC patterns revealed a decrease in connectivity within 6 brain networks during the violence-related compared to the non-violence-related condition: three sensory-motor networks, the reward network, the default mode network (DMN), and the right-lateralized frontoparietal network. Playing violent racing games may change functional brain connectivity, in particular and even after controlling for event frequency, in the reward network and the DMN. These changes may underlie the short-term increase of aggressive affects, cognitions, and behaviors as observed after playing violent video games.
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The hypothalamus controls feeding behavior. Since central opioid systems may regulate feeding behavior, we examined the role of μ-, δ- and κ-opioid receptors in the lateral hypothalamus (LH), the hunger center, in feeding behavior of mice. Non-selective (naloxone; 3 mg/kg, s.c.) and selective μ- (β-funaltrexamine, β-FNA; 10 mg/kg, s.c.), δ- (naltrindole; 3 mg/kg, s.c.) and κ- (norbinaltorphimine, norBNI; 20 mg/kg, s.c.) opioid receptor antagonists significantly decreased food intake in food-deprived mice. ⋯ Naloxone (3mg/kg, s.c.) significantly increased the GABA level in the LH and both bicuculline and the GABA release inhibitor 3-mercaptopropionic acid (3-MP, 5 μg/side) attenuated the inhibitory effect of naloxone on feeding behavior. 3-MP also attenuated the effects of β-FNA and norBNI, but not that of naltrindole. These results show that opioid systems in the LH regulate feeding behavior through orexin neurons. Moreover, μ- and κ-, but not δ-, opioid receptor antagonists inhibit feeding behavior by activating GABA neurons in the LH.