{'fraction_non_alphanumeric': 0.031031031031031032, 'fraction_numerical': 0.018018018018018018, 'mean_word_length': 5.756756756756757, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Functional activity of 5‐HT2 receptors in the modulation of the sleep/wakefulness states

SUMMARY  In the light of recent pharmacological investigations using agonists and antagonists that have potent actions on 5‐hydroxytryptamine‐2 (5‐HT2) receptors, the possible functional role of 5‐HT2 receptors in the modulation of the sleep/wakefulness states was examined. Data obtained from animals and from clinical studies suggest that serotonin may exert an inhibitory control on deep slow‐wave sleep (SWS) through 5‐HT2 receptors. In further investigations, the existence of a diurnal variation in the functional activity of 5‐HT2 receptors, that depends on the day/night cycle and/or the melatonin rhythm, was revealed. Questions remain with regard to the physiological significance of the 5‐HT2 receptor‐mediated deep SWS regulation, the anatomical site(s) of 5‐HT2 receptors involved in this regulation and the mechanism underlying diurnal fluctuations in the functional activity of 5‐HT2 receptors.