Orexin/hypocretin neurons have a crucial role in the regulation of sleep and wakefulness. Recent optogenetic studies revealed that the activation or inhibition of orexin neuronal activity affects the probability of sleep/wakefulness transition in the acute phase. To expand our understanding of how orexin neurons maintain wakefulness, we generated new transgenic mice in which orexin neurons expr...

Entrainment of anticipatory activity and wakefulness to nutrient availability is a poorly understood component of energy homeostasis. Restricted feeding (RF) paradigms with a periodicity of 24 h rapidly induce entrainment of rhythms anticipating food presentation that are independent of master clocks in the suprachiasmatic nucleus (SCN) but do require other hypothalamic structures. Here, we rep...

The suprachiasmatic nucleus exhibits circadian rhythmicity in fetal and infant rats, but little is known about the consequences of this rhythmicity for infant behavior. Here, in experiment 1, the authors measured sleep and wakefulness in rats during the day and night in postnatal day (P)2, P8, P15, and P21 subjects. As early as P2, day-night differences in sleep-wake activity were detected. Noc...

Rapid eye movement sleep (REMS) is associated with intense neuronal activity, rapid eye movements, muscular atonia and dreaming. Another important feature in REMS is the instability in autonomic, especially in cardiovascular regulation. The neural mechanisms underpinning the variability in heart rate (VHR) during REMS are not known in detail, especially in humans. During wakefulness, the right ...

Human and animal studies have identified an especially critical role for the brainstem parabrachial (PB) complex in regulating electrocortical (electroencephalogram [EEG]) and behavioral arousal: lesions of the PB complex produce a monotonous high-voltage, slow-wave EEG and eliminate spontaneous behaviors. We report here that targeted chemogenetic activation of the PB complex produces sustained...

The neuropeptide orexin (also known as hypocretin) is hypothesized to play a critical role in the regulation of sleep-wake behavior. Lack of orexin produces narcolepsy, which is characterized by poor maintenance of wakefulness and intrusions of rapid eye movement (REM) sleep or REM sleep-like phenomena into wakefulness. Orexin neurons heavily innervate many aminergic nuclei that promote wakeful...

BACKGROUND Significant advances have been made in our understanding of subcortical processes related to anesthetic- and sleep-induced unconsciousness, but the associated changes in cortical connectivity and cortical neurochemistry have yet to be fully clarified. METHODS Male Sprague-Dawley rats were instrumented for simultaneous measurement of cortical acetylcholine and electroencephalographi...

Affective experiences occur across the wake-sleep cycle—from active wakefulness to resting (i.e., mind-wandering) sleep dreaming). Yet, we know little about dynamics of affect these states. We compared affective ratings waking, mind-wandering, and dream episodes. Results showed that mind-wandering was more positively valenced than dreaming, both dreaming were negatively wakefulness. also partic...