The Corticostriatal Adenosine A2A Receptor Controls Maintenance and Retrieval of Spatial Working Memory

BACKGROUND: Working memory (WM) taps into multiple executive processes including encoding, maintenance, and retrieval of information, but the molecular and circuit modulation of these WM processes remains undefined due to the lack of methods to control G protein-coupled receptor signaling with temporal resolution of seconds. METHODS: By coupling optogenetic control of the adenosine A(2A) receptor (A(2A)R) signaling, the Cre-loxP-mediated focal A(2A)R knockdown with a delayed non-match-to-place (DNMTP) task, we investigated the effect of optogenetic activation and focal knockdown of A(2A)Rs in the dorsomedial striatum (n = 8 to 14 per group) and medial prefrontal cortex (n = 16 to 22 per group) on distinct executive processes of spatial WM. We also evaluated the therapeutic effect of the A(2A)R antagonist KW6002 on delayed match-to-sample/place tasks in 6 normal and 6 MPTP-treated cynomolgus monkeys. RESULTS: Optogenetic activation of striatopallidal A(2A)Rs in the dorsomedial striatum selectively at the delay and choice (not sample) phases impaired DNMTP performance. Optogenetic activation of A(2A)Rs in the medial prefrontal cortex selectively at the delay (not sample or choice) phase improved DNMTP performance. The corticostriatal A(2A)R control of spatial WM was specific for a novel but not well-trained DNMTP task. Focal dorsomedial striatum A(2A)R knockdown or KW6002 improved DNMTP performance in mice. Last, KW6002 improved spatial WM in delayed match-to-sample and delayed match-to-place tasks of normal and dopamine-depleted cynomolgus monkeys. CONCLUSIONS: The A(2A)Rs in striatopallidal and medial prefrontal cortex neurons exert distinctive control of WM maintenance and retrieval to achieve cognitive stability and flexibility. The procognitive effect of KW6002 in nonhuman primates provides the preclinical data to translate A(2A)R antagonists for improving cognitive impairments in Parkinson's disease.