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Abstract Optochemistry, an emerging pharmacologic approach in which light is used to selectively activate or deactivate molecules, has the potential to alleviate symptoms, cure diseases, and improve quality of life while preventing uncontrolled drug effects. The development of in-vivo applications for optochemistry to render brain cells photoresponsive without relying on genetic engineering has been progressing slowly. The nucleus accumbens (NAc) is a region for the regulation of slow-wave sleep (SWS) through the integration of motivational stimuli. Adenosine emerges as a promising candidate molecule for activating indirect pathway neurons of the NAc expressing adenosine A2A receptors (A2ARs) to induce SWS. Here, we developed a brain-permeable positive allosteric modulator of A2ARs (A2AR PAM) that can be rapidly photoactivated with visible light (λ > 400 nm) and used it optoallosterically to induce SWS in the NAc of freely behaving male mice by increasing the activity of extracellular adenosine derived from astrocytic and neuronal activity.

Background: Insomnia is associated with psychiatric illnesses such as bipolar disorder or schizophrenia. Treating insomnia improves psychotic symptoms severity, quality of life, and functional outcomes. Patients with psychiatric disorders are often dissatisfied with the available therapeutic options for their insomnia. In contrast, positive allosteric modulation of adenosine A2A receptors (A2ARs) leads to slow-wave sleep without cardiovascular side effects in contrast to A2AR agonists.Methods: We investigated the hypnotic effects of A2AR positive allosteric modulators (PAMs) in mice with mania-like behavior produced by ablating GABAergic neurons in the ventral medial midbrain/pons area and in a mouse model of schizophrenia by knocking out of microtubule-associated protein 6. We also compared the properties of sleep induced by A2AR PAMs in mice with mania-like behavior with those induced by DORA-22, a dual orexin receptor antagonist that improves sleep in pre-clinical models, and the benzodiazepine diazepam.Results: A2AR PAMs suppress insomnia associated with mania- or schizophrenia-like behaviors in mice. A2AR PAM-mediated suppression of insomnia in mice with mania-like behavior was similar to that mediated by DORA-22, and, unlike diazepam, did not result in abnormal sleep.Conclusion: A2AR allosteric modulation may represent a new therapeutic avenue for sleep disruption associated with bipolar disorder or psychosis.

Optochemistry, an emerging pharmacologic approach in which light is used to selectively activate or deactivate molecules, has the potential to alleviate symptoms, cure diseases, and improve quality of life while preventing uncontrolled drug effects. The development of in-vivo applications for optochemistry to render brain cells photoresponsive without relying on genetic engineering has been progressing slowly. The nucleus accumbens (NAc) is a region for the regulation of slow-wave sleep (SWS) through the integration of motivational stimuli. Adenosine emerges as a promising candidate molecule for activating indirect pathway neurons of the NAc expressing adenosine A2A receptors (A2A Rs) to induce SWS. Here, we developed a brain-permeable positive allosteric modulator of A2A Rs (A2A R PAM) that can be rapidly photoactivated with visible light (λ > 400 nm) and used it optoallosterically to induce SWS in the NAc of freely behaving male mice by increasing the activity of extracellular adenosine derived from astrocytic and neuronal activity. [ABSTRACT FROM AUTHOR]

Background: Insomnia is associated with psychiatric illnesses such as bipolar disorder or schizophrenia. Treating insomnia improves psychotic symptoms severity, quality of life, and functional outcomes. Patients with psychiatric disorders are often dissatisfied with the available therapeutic options for their insomnia. In contrast, positive allosteric modulation of adenosine A2A receptors (A2ARs) leads to slow-wave sleep without cardiovascular side effects in contrast to A2AR agonists. Methods: We investigated the hypnotic effects of A2AR positive allosteric modulators (PAMs) in mice with mania-like behavior produced by ablating GABAergic neurons in the ventral medial midbrain/pons area and in a mouse model of schizophrenia by knocking out of microtubule-associated protein 6. We also compared the properties of sleep induced by A2AR PAMs in mice with mania-like behavior with those induced by DORA-22, a dual orexin receptor antagonist that improves sleep in pre-clinical models, and the benzodiazepine diazepam. Results: A2AR PAMs suppress insomnia associated with mania- or schizophrenialike behaviors in mice. A2AR PAM-mediated suppression of insomnia in mice with mania-like behavior was similar to that mediated by DORA-22, and, unlike diazepam, did not result in abnormal sleep. Conclusion: A2AR allosteric modulation may represent a new therapeutic avenue for sleep disruption associated with bipolar disorder or psychosis. [ABSTRACT FROM AUTHOR]

Objective: Insomnia is one of the most common sleep problems with an estimated prevalence of 10% to 15% in the general population. Although adenosine A2A receptor (A2AR) agonists strongly induce sleep, their cardiovascular effects preclude their use in treating sleep disorders. Enhancing endogenous A2AR signaling, however, may be an alternative strategy for treating insomnia, because adenosine levels in the brain accumulate during wakefulness. Methods: We established A2AR-expressing Chinese hamster ovary cells to measure cAMP produced upon A2AR activation by using a fluorescence resonance energy transfer immunoassay. Subsequently, we screened several thousand small-molecule compounds for allosteric effects at A2AR in the cell-culture bioassay. Results: We identified a positive allosteric modulator for A2AR, termed A2AR PAM-1. When we examined the sleep-inducing activity of A2AR PAM-1 by monitoring the electroencephalogram, we found that the intraperitoneal (IP) administration of A2AR PAM-1 dose dependently (30-75 mg/kg) increased the total amount of slow wave sleep (SWS). In addition, the SWSinducing effect of A2AR PAM-1 was suppressed by A2AR antagonist ZM241385 (15 mg/kg, IP) and abolished in A2AR knockout mice. In contrast to A2AR agonist CGS 21680, blood pressure measured by using an electrosphygmomanometer and heart rate monitored by using telemetry transmitters were not affected after IP administration of A2AR PAM-1. Conclusion: Small molecules like the A2AR allosteric modulator A2AR PAM-1 may help people with sleep problems to fall asleep. [ABSTRACT FROM AUTHOR]