Whole-brain circuit dissection in free-moving animals reveals cell-specific mesocorticolimbic networks

• Published in: The Journal of clinical investigation Vol. 123; no. 12; pp. 342 - 350
• Main Authors: Michaelides, Michael, Anderson, Sarah Ann R, Ananth, Mala, Smirnov, Denis, Thanos, Panayotis K, Neumaier, John F, Wang, Gene-Jack, Volkow, Nora D, Hurd, Yasmin L
• Format: Journal Article
• Language: English
• Published: American Society for Clinical Investigation 01.12.2013
• Subjects: Brain; Nervous system diseases; Physiological aspects; United States
• ISSN: 0021-9738; 1558-8238

The ability to map the functional connectivity of discrete cell types in the intact mammalian brain during behavior is crucial for advancing our understanding of brain function in normal and disease states. We combined designer receptor exclusively activated by designer drug (DREADD) technology and behavioral imaging with µPET and [.sup.18.F]fluorodeoxyglucose (FDG) to generate whole-brain metabolic maps of cell-specific functional circuits during the awake, freely moving state. We have termed this approach DREADD-assisted metabolic mapping (DREAMM) and documented its ability in rats to map whole-brain functional anatomy. We applied this strategy to evaluating changes in the brain associated with inhibition of prodynorphin-expressing (Pdyn-expressing) and of proenkephalin-expressing (Penk-expressing) medium spiny neurons (MSNs) of the nucleus accumbens shell (NAcSh), which have been implicated in neuropsychiatric disorders. DREAMM revealed discrete behavioral manifestations and concurrent engagement of distinct corticolimbic networks associated with dysregulation of Pdyn and Penk in MSNs of the NAcSh. Furthermore, distinct neuronal net-works were recruited in awake versus anesthetized conditions. These data demonstrate that DREAMM is a highly sensitive, molecular, high-resolution quantitative imaging approach.