Alan Jung Park

Brief periods of sleep loss have long-lasting consequences such as impaired memory consolidation. Structural changes in synaptic connectivity have been proposed as a substrate of memory storage. Here, we examine the impact of brief periods of sleep deprivation on dendritic structure. In mice, we find that five hours of sleep deprivation decreases dendritic spine numbers selectively in hippocampal area CA1 and increased activity of the filamentous actin severing protein cofilin. Recovery sleep no

Sleep deprivation is a common problem of considerable health and economic impact in today's society. Sleep loss is associated with deleterious effects on cognitive functions such as memory and has a high comorbidity with many neurodegenerative and neuropsychiatric disorders. Therefore, it is crucial to understand the molecular basis of the effect of sleep deprivation in the brain. In this study, we combined genome-wide and traditional molecular biological approaches to determine the cellular and

Sleep deprivation is a public health epidemic that causes wide-ranging deleterious consequences, including impaired memory and cognition. Protein synthesis in hippocampal neurons promotes memory and cognition. The kinase complex mammalian target of rapamycin complex 1 (mTORC1) stimulates protein synthesis by phosphorylating and inhibiting the eukaryotic translation initiation factor 4E-binding protein 2 (4EBP2). We investigated the involvement of the mTORC1-4EBP2 axis in the molecular mechanisms

Decreased pleasure-seeking (anhedonia) forms a core symptom of depression. Stressful experiences precipitate depression and disrupt reward-seeking, but it remains unclear how stress causes anhedonia. We recorded simultaneous neural activity across limbic brain areas as mice underwent stress and discovered a stress-induced 4 Hz oscillation in the nucleus accumbens (NAc) that predicts the degree of subsequent blunted reward-seeking. Surprisingly, while previous studies on blunted reward-seeking fo

Proline dehydrogenase (PRODH), which degrades L-proline, resides within the schizophrenia-linked 22q11.2 deletion suggesting a role in disease. Supporting this, elevated L-proline levels have been shown to increase risk for psychotic disorders. Despite the strength of data linking PRODH and L-proline to neuropsychiatric diseases, targets of disease-relevant concentrations of L-proline have not been convincingly described. Here, we show that Prodh-deficient mice with elevated CNS L-proline displa

Long-lasting forms of synaptic plasticity and memory require de novo protein synthesis. Yet, how learning triggers this process to form memory is unclear. Translin/trax is a candidate to drive this learning-induced memory mechanism by suppressing microRNA-mediated translational silencing at activated synapses. We find that mice lacking translin/trax display defects in synaptic tagging, which requires protein synthesis at activated synapses, and long-term memory. Hippocampal samples harvested fro

Activity-dependent local protein synthesis is critical for synapse-specific, persistent plasticity. Abnormalities in local protein synthesis have been implicated in psychiatric disorders. We have recently identified the translin/trax microRNA-degrading enzyme as a novel mediator of protein synthesis at activated synapses. Additionally, translin knockout (KO) mice, which lack translin/trax, exhibit some of the behavioral abnormalities found in a mouse model of fragile X syndrome (fragile X mental

We propose a novel multi-photodiode array (MPDA) based retinal implant IC with on/off stimulation strategy for a visual prosthesis with improved spatial resolution. An active pixel sensor combined with a comparator enables generation of biphasic current pulses when light intensity meets a threshold condition. The threshold is tuned by changing the discharging time of the active pixel sensor for various light intensity environments. A prototype of the 30-channel retinal implant IC was fabricated

우리나라의 모텔촌은 도시 내에서 교육환경, 주거환경, 도시미관에 부정적인 영향을 미치는 측면이 꾸준히 지적받아 왔다. 이러한 상황에서 모텔촌의 가로경관 관리ㆍ개선은 모텔촌의 영업에영향을 적게 주면서도 모텔촌의 이미지를 개선할 수 있는 방안이다. 그러나 현재 국내외에서 모텔촌의 가로경관 특성에 대한 연구는 활발하게 이루어지지 않은 상황이다. 따라서 본 연구에서는모텔촌 가로경관의 특성을 파악하여 향후 모텔촌 가로경관의 관리 방향을 제시하고자 하였다. 연구결과 모텔촌의 가로경관은 경관미 측면에서 인근 상업가로에 비해 다소 떨어지며, ‘답답하다’, ‘막혀 있다’, ‘멋없다’, ‘불쾌하다’, ‘획일적이다’ 등의 느낌을 주는 것으로 나타났다. 또한 요인분석 결과, 모텔촌의 경관 이미지 평가에는 조화성, 개방성의 두 가지 요인이 존재함을 확인하였으며, 특히 개방성 측면에서 모텔촌과 인근 상업가로가 차이를 보이는 것으로 분석되었다. 다중회귀분석의 결과, 모텔촌의 경관미에 개방성보다 조화성이 더욱

Rapid adaptation to novel environments is crucial for survival, and this ability is impaired in many neuropsychiatric disorders. Understanding neural adaptation to novelty exposure therefore has therapeutic implications. Here, I found that novelty induces time-dependent theta (4-12Hz) oscillatory dynamics in brain circuits including the medial prefrontal cortex (mPFC), ventral hippocampus (vHPC), and ventral tegmental area (VTA), but not dorsal hippocampus (dHPC), as mice adapt to a novel enviro