https://scholar.dgist.ac.kr/handle/20.500.11750/9978 2026-04-10T05:05:49Z https://scholar.dgist.ac.kr/handle/20.500.11750/59927 Title: Kv7 Channels as an Important Contributor to Alcohol-Induced Modulation of Neuronal Excitability in Neonatal Rat Superior Cervical Ganglion Author(s): Jeong, Da-Jeong; Woo, Jin-Nyeong; Yun, Tery; Baek, Myungin; Suh, Byung-Chang Abstract: Normal alcohols (n-alcohols) exhibit contrasting effects on neuronal excitability; specifi- cally, ethanol enhances neuronal firing, while hexanol suppresses it. Both compounds are known to inhibit sodium currents, yet the mechanisms behind their differing effects remain unclear. Our previous studies demonstrated that Kv7 channels are modulated differently by alcohol chain length, prompting investigation into their role in these contrasting effects. We conducted whole-cell patch clamp recordings on neonatal (P5-P7) rat superior cervical ganglion neurons to assess alcohol impacts on action potential firing and ionic currents, utilizing tetrodotoxin (TTX), XE991, and retigabine (RTG). Ethanol (100 mM) increased action potential frequency, whereas hexanol (3 mM) decreased it, despite both inhibiting sodium currents by 12% and 45%, respectively. Notably, ethanol inhibited Kv7 currents by 16%, while hexanol enhanced them by 29%. TTX alone did not affect firing frequency until sodium current inhibition exceeded 76%, indicating moderate sodium channel blockade cannot fully explain the effects of alcohol. XE991 increased firing frequency and depo- larized the resting membrane potential, while retigabine produced opposite effects. The combination of TTX with Kv7 modulators replicated the effects observed with each alco- hol. These findings suggest Kv7 channel modulation plays an important role in the chain length-dependent effects of alcohol on neuronal excitability. 2025-10-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58331 Title: Electrical Stimulation of the M1 Activates Somatostatin Interneurons in the S1: Potential Mechanisms Underlying Pain Suppression Author(s): Park, Junhee; Kim, Yong Geon; Kim, Taehyeon; Baek, Myungin Abstract: Chronic pain affects millions globally, yet no universally effective treatment exists. The primary motor cortex (M1) has been a key target for chronic pain therapies, with electrical stimulation of the M1 (eMCS) showing promise. However, the mechanisms underlying M1-mediated analgesic effects are not fully understood. We investigated the role of the primary somatosensory cortex (S1) in M1-mediated analgesia using a neuropathic pain mouse model. In this model, neuropathic pain is associated with increased spontaneous activity of layer V pyramidal neurons (LV-PNs) in the S1, partly attributed to the reduced activity of somatostatin-expressing inhibitory neurons (SST+ INs), which normally suppress LV-PNs. While manipulation of either LV-PNs or SST+ INs has been shown to alleviate pain, the role of S1 in M1-mediated analgesia has not been identified. Using multichannel silicon probes, we applied eMCS to neuropathic mice and observed significant analgesia. Histological analyses revealed that eMCS activated SST+ INs and suppressed hyperactivity of LV-PNs in the S1, suggesting that eMCS suppresses pain by modulating S1 neuronal circuits, alongside other pain-related regions. Notably, eMCS induced long-lasting analgesia, persisting for at least 2 d poststimulation. These findings implicate S1 as a critical mediator of eMCS-induced analgesia and suggest eMCS as a potential durable therapeutic strategy for chronic pain. 2025-03-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/57299 Title: Astrocytic inhibition of lateral septal neurons promotes diverse stress responses Author(s): Seo, Kain; Won, Sanghyun; Lee, Hee-Yoon; Sin, Yeonju; Lee, Sangho; Park, Hyejin; Kim, Yong Geon; Yang, Seo Young; Kim, Dong-Jae; Suk, Kyoungho; Koo, Ja Wook; Baek, Myungin; Choi, Se-Young; Lee, Hyosang Abstract: Inhibitory neuronal circuits within the lateral septum (LS) play a key role in regulating mood and stress responses. Even though glial cells can modulate these circuits, the impact of astrocytes on LS neural circuits and their functional interactions remains largely unexplored. Here, we demonstrate that astrocytes exhibit increased intracellular Ca²⁺ levels in response to aversive sensory and social stimuli in both male and female mice. This astrocytic Ca²⁺ elevation inhibits neighboring LS neurons by reducing excitatory synaptic transmissions through A1R-mediated signaling in both the dorsal (LSd) and intermediate LS (LSi) and enhancing inhibitory synaptic transmission via A2AR-mediated signaling in the LSi. At the same time, astrocytes reduce inhibitory tone on distant LS neurons. In the LSd, astrocytes promote social avoidance and anxiety, as well as increased heart rate in socially stressed male mice. In contrast, astrocytes in the LSi contribute to elevated heart rate and heightened blood corticosterone levels in unstressed male mice. These results suggest that the dynamic interactions between astrocytes and neurons within the LS modulate physiological and behavioral responses to stressful experiences. © The Author(s) 2024. 2024-10-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/17114 Title: Little skate genome provides insights into genetic programs essential for limb-based locomotion Author(s): Yoo, DongAhn; Park, Junhee; Lee, Chul; Song, Injun; Lee, Young Ho; Yun, Tery; Lee, Hyemin; Heguy, Adriana; Han, Jae Yong; Dasen, Jeremy S.; Kim, Heebal; Baek, Myungin Abstract: The little skate Leucoraja erinacea, a cartilaginous fish, displays pelvic fin driven walking-like behavior using genetic programs and neuronal subtypes similar to those of land vertebrates. However, mechanistic studies on little skate motor circuit development have been limited, due to a lack of high-quality reference genome. Here, we generated an assembly of the little skate genome, with precise gene annotation and structures, which allowed post-genome analysis of spinal motor neurons (MNs) essential for locomotion. Through interspecies comparison of mouse, skate and chicken MN transcriptomes, shared and divergent gene expression profiles were identified. Comparison of accessible chromatin regions between mouse and skate MNs predicted shared transcription factor (TF) motifs with divergent ones, which could be used for achieving differential regulation of MN-expressed genes. A greater number of TF motif predictions were observed in MN-expressed genes in mouse than in little skate. These findings suggest conserved and divergent molecular mechanisms controlling MN development of vertebrates during evolution, which might contribute to intricate gene regulatory networks in the emergence of a more sophisticated motor system in tetrapods. © 2022, Yoo, Park et al. 2022-09-30T15:00:00Z