Chronic alcohol drinking persistently suppresses thalamostriatal excitation of cholinergic neurons to impair cognitive flexibility

• Published in: The Journal of clinical investigation Vol. 132; no. 4; pp. 1 - 14
• Main Authors: Ma, Tengfei, Huang, Zhenbo, Xie, Xueyi, Cheng, Yifeng, Zhuang, Xiaowen, Childs, Matthew J, Gangal, Himanshu, Wang, Xuehua, Smith, Laura N, Smith, Rachel J, Zhou, Yubin, Wang, Jun
• Format: Journal Article
• Language: English
• Published: United States American Society for Clinical Investigation 15-02-2022
• Subjects: Alcohol Drinking - metabolism; Alcohol Drinking - physiopathology; Alcohol use; Alcoholism; Alcoholism - metabolism; Alcoholism - physiopathology; Animals; Biomedical research; Brain research; Cholinergic mechanisms; Cholinergic Neurons - metabolism; Chronic Disease; Cognition; Cognition disorders; Cognitive ability; Complications and side effects; Corpus Striatum - metabolism; Corpus Striatum - physiopathology; Decision making; Dopamine; Dopamine D1 receptors; Dopamine D2 receptors; Drinking behavior; Flexibility; Glutamatergic transmission; Health aspects; Interneurons; Long-term potentiation; Mice; Mice, Transgenic; Neostriatum; Neural circuitry; Neurons; Neuroscience; Reversal learning; Risk factors; Spiny neurons; Sucrose; Thalamus; Transgenic animals; Withdrawal; United States; Neuroscience; Psychiatric diseases; Behavior; Addiction
• ISSN: 1558-8238; 0021-9738; 1558-8238
• DOI: 10.1172/JCI154969

Exposure to addictive substances impairs flexible decision making. Cognitive flexibility is mediated by striatal cholinergic interneurons (CINs). However, how chronic alcohol drinking alters cognitive flexibility through CINs remains unclear. Here, we report that chronic alcohol consumption and withdrawal impaired reversal of instrumental learning. Chronic alcohol consumption and withdrawal also caused a long-lasting (21 days) reduction of excitatory thalamic inputs onto CINs and reduced pause responses of CINs in the dorsomedial striatum (DMS). CINs are known to inhibit glutamatergic transmission in dopamine D1 receptor-expressing medium spiny neurons (D1-MSNs) but facilitate this transmission in D2-MSNs, which may contribute to flexible behavior. We discovered that chronic alcohol drinking impaired CIN-mediated inhibition in D1-MSNs and facilitation in D2-MSNs. Importantly, in vivo optogenetic induction of long-term potentiation of thalamostriatal transmission in DMS CINs rescued alcohol-induced reversal learning deficits. These results demonstrate that chronic alcohol drinking reduces thalamic excitation of DMS CINs, compromising their regulation of glutamatergic transmission in MSNs, which may contribute to alcohol-induced impairment of cognitive flexibility. These findings provide a neural mechanism underlying inflexible drinking in alcohol use disorder.