https://scholar.dgist.ac.kr/handle/20.500.11750/13550 2026-10-22T09:59:38Z https://scholar.dgist.ac.kr/handle/20.500.11750/61011 Title: Distinct lateral hypothalamic GABAergic ensembles encode motivational salience and value-scaled consumption Author(s): Lee, Myungsun; Jung, Sieun; Kwon, JiSoo Jennifer; Kondaurova, Anna; Nam, Myungsun; Kim, Donguk; Hyun, Jung Ho; Kim, Sung-Yon Abstract: Motivated behaviors span an approach-avoidance axis. Vgat-expressing lateral hypothalamic GABAergic neurons (LHVgat neurons) regulate motivated behaviors, but how distinct ensembles represent motivationally significant stimuli and consummatory actions across homeostatic needs remains unclear. Using longitudinal two-photon Ca2+ imaging to track individual neurons across behavioral sessions, we identify two dissociable LHVgat ensembles. One responds to aversive thermal stimuli and food-associated cues, including inaccessible food and learned predictors, but not to a behaviorally neutral auditory tone that evokes pupil dilation, supporting motivational salience coding across aversive and appetitive contexts rather than reflecting arousal alone. A second ensemble is preferentially engaged during ingestion across eating and drinking. Food-cue responses vary across stimuli in a manner consistent with their relative appetitive value, and ingestion responses scale with hunger and nutrient concentration; GLP-1 receptor agonism attenuates both. These findings reveal a functional division between motivationally salient cue processing and value-scaled consummatory encoding in LHVgat circuits. 2026-09-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60615 Title: The hippocampal CA3 area implements sequence learning of discontinuous episodes Author(s): Eom, Kisang; Kim, Yujin; Lee, Hyoung-Ro; Lee, Yolguk; Han, Young-Eun; Shin, Jiwoo; Lee, Jae Sung; Hyun, Jung Ho; Park, Alan J.; Lee, Suk-Ho Abstract: Sequence learning requires linking memories of adjacent events by sharing ensemble cells. It remains unclear how the hippocampal CA3 links non-overlapping memory representations in sequence learning. High frequency mossy fiber inputs to a CA3 pyramidal cell downregulate Kv1.2 in distal apical dendrites to enhance its voltage response to perforant pathway inputs, and the high excitability is restored by subsequent perforant pathway inputs. Consistent with this notion, we found that CA3 ensemble cells activated by a novel context display high excitability, and their high excitability state is restored by re-activation during the second visit to a similar but distinct context. Computational modeling suggests that this bi-directional excitability regulation enables ordered association of orthogonal neuronal ensembles representing sequential events. Supporting this, CA3-specific Kcna2 + /- mice, which lack synaptic regulation of excitability, exhibited impaired sequence learning. These findings reveal the synaptic mechanisms by which the CA3 network encodes sequential memories. 2026-04-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/59270 Title: Ultrasound localization microscopy lite (ULM lite): ultrasound localization microscopy with resource-efficient signal processing scheme Author(s): Seong, Hyojin; Jung, Jinhwan; Jung, Dongkyu; Guezzi, Nizar; Nam, Sangwoo; Lee, Sangheon; Noman, Muhammad; Her, Taehoon; Cho, Eungyeong; Yoon, Heechul; Lee, Taeyoung; Hyun, Jung Ho; Yu, Jaesok Abstract: Ultrasound localization microscopy (ULM) is a groundbreaking, non-invasive imaging tool for monitoring vascular hemodynamics and neuronal activities in rodent models with exceptional spatial resolution. Despite its potential, the extensive data size required by the current ULM framework poses significant limitations to its broader applications. This study addresses these challenges by introducing sub-Nyquist sampling of the bandlimited radio-frequency (RF) signals, a method designed to reduce resource demands while preserving image quality. In this study, we experimentally demonstrate the in vivo feasibility of the proposed method. Our results show that 67 % of band-limited signal images achieve a high signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), comparable to those of conventional 200 % bandwidth signals. Even under stringent data reduction conditions, the proposed approach reduces the data size by approximately one-third without compromising image quality. These results highlight the potential of the proposed approach holds significant promise for enhancing the efficiency and practicality of ULM, facilitating the non-invasive visualization of deep neuronal activities with improved resource efficiency. 2026-02-28T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/58886 Title: High-frequency (> 65 MHz) broadband transparent transducer with ultrathin gold electrode for dual-mode photoacoustic and laser-induced ultrasound microscopy Author(s): Park, Sunghun; Hong, Woongki; Park, Hyeongyu; Lee, Eunji; Nam, Sangwoo; Jung, Jin Hwan; Hyun, Jung Ho; Yu, Jaesok; Kang, Hongki; Chang, Jin Ho Abstract: For high-performance combined photoacoustic (PA) and Ultrasound (US) microscopy, precise coaxial alignment of the US and laser beams is essential. This can be realized using broadband transparent ultrasound transducers (TUTs). However, the current dual-mode imaging systems encounter significant challenges in simultaneous PA and US data acquisition due to sequential transmission of light and ultrasound and mechanical movement of dual-mode probes, leading to longer acquisition times and potential registration inaccuracies. To overcome these limitations, we propose a recently developed high-frequency broadband TUT with an ultrathin (< 10 nm) gold electrode, achieving a center frequency of 65.6 MHz and a –6 dB bandwidth of 71.6 %. The ultrathin gold electrode facilitates laser-induced ultrasound (LUS), enabling simultaneous acquisition of PA and US images. In vivo experiments demonstrate that LUS imaging can effectively replace conventional US imaging, offering highly efficient dual-mode PA/US imaging with minimized registration errors. 2025-09-30T15:00:00Z