https://scholar.dgist.ac.kr/handle/20.500.11750/779 2026-04-04T13:36:30Z https://scholar.dgist.ac.kr/handle/20.500.11750/57282 Title: Bidirectional Control of Emotional Behaviors by Excitatory and Inhibitory Neurons in the Orbitofrontal Cortex Author(s): Kim, Jihoon; Choi, Mijung; Lee, Jimin; Park, Inah; Kim, Kyungjin; Choe, Han Kyoung Abstract: The orbitofrontal cortex (OFC) plays a crucial role in mood disorders; however, its specific role in the emotional behaviors of mice remains unclear. This study investigates the bidirectional control of emotional behaviors using population calcium dynamics and optogenetic manipulation of OFC neurons. Fiber photometry of OFC neurons revealed that OFC excitatory neurons consistently responded to the onset and offset of aversive conditions, showing decreased activation in response to anxiogenic and stressful stimuli, including tail suspension, restraint stress, and exposure to the center of the open field. The selective activation of excitatory neurons in the OFC reduced the time spent in the center of the open field, whereas optogenetic activation of inhibitory neurons in the OFC induced the opposite behavioral changes. We also provided a brain-wide activation map for OFC excitatory and inhibitory neuron activation. Our findings demonstrate that excitatory and inhibitory neurons in the OFC play opposing roles in the regulation of emotional behaviors. These results provide new insights into the neural mechanisms underlying emotional control and suggest that targeting these specific neuronal populations may offer novel therapeutic strategies for emotional disorders. Copyright © Experimental Neurobiology 2024. 2024-09-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/56878 Title: Role of the circadian nuclear receptor REV-ERBα in dorsal raphe serotonin synthesis in mood regulation Author(s): Park, Inah; Choi, Mijung; Kim, Jeongah; Jang, Sangwon; Kim, Doyeon; Kim, Jihoon; Choe, Youngshik; Geum, Dongho; Yu, Seong-Woon; Choi, Ji-Woong; Moon, Cheil; Choe, Han Kyoung; Son, Gi Hoon; Kim, Kyungjin Abstract: Affective disorders are frequently associated with disrupted circadian rhythms. The existence of rhythmic secretion of central serotonin (5-hydroxytryptamine, 5-HT) pattern has been reported; however, the functional mechanism underlying the circadian control of 5-HTergic mood regulation remains largely unknown. Here, we investigate the role of the circadian nuclear receptor REV-ERBα in regulating tryptophan hydroxylase 2 (Tph2), the rate-limiting enzyme of 5-HT synthesis. We demonstrate that the REV-ERBα expressed in dorsal raphe (DR) 5-HTergic neurons functionally competes with PET-1—a nuclear activator crucial for 5-HTergic neuron development. In mice, genetic ablation of DR 5-HTergic REV-ERBα increases Tph2 expression, leading to elevated DR 5-HT levels and reduced depression-like behaviors at dusk. Further, pharmacological manipulation of the mice DR REV-ERBα activity increases DR 5-HT levels and affects despair-related behaviors. Our findings provide valuable insights into the molecular and cellular link between the circadian rhythm and the mood-controlling DR 5-HTergic systems. © The Author(s) 2024. 2024-07-31T15:00:00Z