Sleep control is ascribed to a two-process model, a widely accepted concept that posits homoeostatic drive and a circadian process as the major sleep-regulating factors. Cognitive and emotional factors also influence sleep–wake behaviour; however, the precise circuit mechanisms underlying their effects on sleep control are unknown. Previous studies suggest that adenosine has a role affecting behavioural arousal in the nucleus accumbens (NAc), a brain area critical for reinforcement and reward. Here, we show that chemogenetic or optogenetic activation of excitatory adenosine A2A receptor-expressing indirect pathway neurons in the core region of the NAc strongly induces slow-wave sleep. Chemogenetic inhibition of the NAc indirect pathway neurons prevents the sleep induction, but does not affect the homoeostatic sleep rebound. In addition, motivational stimuli inhibit the activity of ventral pallidum-projecting NAc indirect pathway neurons and suppress sleep. Our findings reveal a prominent contribution of this indirect pathway to sleep control associated with motivation.

China launched a pilot scheme in March 2010 to lift the ban on short-selling and margintrading for stocks on a designated list. We find that stocks experience negative returns when added to the list. After the ban is lifted, price efficiency increases while stock return volatility decreases. Panel data regressions reveal that intensified short-selling activities are associated with improved price efficiency. Short-sellers trade to eliminate overpricing by selling stocks with higher contemporaneous returns following a downward trend, and their trades predict future returns. In contrast, we find intensified margin-trading activities for stocks with lower contemporaneous returns, and these trades have no return predictive power.

The basal forebrain (BF) cholinergic neurons have long been thought to be involved in behavioral wakefulness and cortical activation. However, owing to the heterogeneity of BF neurons and poor selectivity of traditional methods, the precise role of BF cholinergic neurons in regulating the sleep-wake cycle remains unclear. We investigated the effects of cell-selective manipulation of BF cholinergic neurons on the sleep-wake behavior and electroencephalogram (EEG) power spectrum using the pharmacogenetic technique, the 'designer receptors exclusively activated by designer drugs (DREADD)' approach, and ChAT-IRES-Cre mice. Our results showed that activation of BF cholinergic neurons expressing hM3Dq receptors significantly and lastingly decreased the EEG delta power spectrum, produced low-delta non-rapid eye movement sleep, and slightly increased wakefulness in both light and dark phases, whereas inhibition of BF cholinergic neurons expressing hM4Di receptors significantly increased EEG delta power spectrum and slightly decreased wakefulness. Next, the projections of BF cholinergic neurons were traced by humanized Renilla green fluorescent protein (hrGFP). Abundant and highly dense hrGFP-positive fibers were observed in the secondary motor cortex and cingulate cortex, and sparse hrGFP-positive fibers were observed in the ventrolateral preoptic nucleus, a known sleep-related structure. Finally, we found that activation of BF cholinergic neurons significantly increased c-Fos expression in the secondary motor cortex and cingulate cortex, but decreased c-Fos expression in the ventrolateral preoptic nucleus. Taken together, these findings reveal that the primary function of BF cholinergic neurons is to inhibit EEG delta activity through the activation of cerebral cortex, rather than to induce behavioral wakefulness.

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