Kim, Joung-Hun, M.D., Ph.D.

Associate Professor
Department of Life Science
Division of Molecular and Life Sciences
Neurobiology

Profile |  Research Interests  |  Selected Publications

Profile

Research Interests

Neural network goes on being remodeled throughout the lifetime beyond the development. Synapses, the points of contact and communication between neurons, can vary in their size, strength, and number. These differences in neural network and synapses contribute to the ability to learn and remember. My lab is interested in elucidating how the neurons are interconnected and affect each other, and how synapses are modified at the cellular and molecular level.

Since synapse formation and retraction are closely correlated with synaptic plasticity and long-term memory, we examine how the structural changes of individual synapses contribute to synaptic plasticity and encode the information of synaptic activities. Time-lapse imaging is used to track long-term structural changes of individual synapses.

The remodeling of neural networks
Brain is not made of single domain but of various structures constituting the whole neural network. Each part of brain is wired through projections to other parts. Members of my lab are interested in how the extraordinary complexity and multi-layered regulation of the neural network are achieved and adjusted responding to external stimuli. We investigate the synaptic plasticity which occurs in vivo by implementing electrodes into deep brain structures of live animals. Synaptic events in vitro brain slices are also studied to dissect signal transduction pathways of the synaptic plasticity.

Clinical implications of synaptic regulation
Neurodegenerative diseases are characterized by decline in cognitive ability. Early symptoms of diseases appear apparent with failures in synaptic functions and synaptic plasticity. We pursues the pathophysiology of neurdegenerative diseases such as Alzheimer’s disease and Parkinsonian, which pose serious problems in modern societies. Toward this end, my lab employes a variety of methodologies, electrophysiology (in vivo and in vitro), time-lapse imaging of synaptic structures, and optical determination of bimolecular interaction as well as standard molecular and biochemical assays.

Selected Publications 

1. Joo Y, Lee SH, Ha S, Hong BH, Kim JH, Suh YH, Kim HS. Focal transient ischemia increases APP-BP1 expression in neural progenitor cells. Neuroreport. 2011 Mar 30;22(5):200-5.
2. Kim J, Park BH, Lee JH, Park SK, Kim JH. Cell Type-Specific Alterations in the Nucleus Accumbens by Repeated Exposures to Cocaine. Biol Psychiatry. 2011 Mar 4 (Epub ahead of print).
3. Joo Y, Ha S, Hong BH, Kim JA, Chang KA, Liew H, Kim S, Sun W, Kim JH, Chong YH, Suh YH, Kim HS. Amyloid Precursor Protein Binding Protein-1 Modulates Cell Cycle Progression in Fetal Neural Stem Cells. PLoS One. 2010 Dec 2;5(12):e14203.
4. Park YU, Jeong J, Lee H, Mun JY, Kim JH, Lee JS, Nguyen MD, Han SS, Suh PG, Park SK Disrupted-in-schizophrenia 1 (DISC1) plays essential roles in mitochondria in collaboration with Mitofilin. Proc Natl Acad Sci U S A. 2010 Oct 12;107(41):17785-90. 
5. Jung SY, Kim J, Kwon OB, Jung JH, An K, Jeong AY, Lee CJ, Choi YB, Bailey C, Kandel ER, Kim JH. Input-Specific Synaptic Plasticity in the Amygdala is Regulated by Neuroligin-1 via Postsynaptic NMDA Receptors. Proc Natl Acad Sci U S A. 2010 Mar 9;107(10):4710 -4715.
6. Miniaci MC, Kim JH, Puthanveettil S, Si K, Zhu H, Kandel ER, Bailey C. Sustained CPEB-Dependent Local Protein Synthesis Is Required to Stabilize Synaptic Growth for Persistence of Long-Term Facilitation in Aplysia Neuron 2008 September 25; 59(6): 1024-1036.
7. Kim J*, Jung SY*, Lee YK, Park SK, Choi JS, Lee CJ, Kim HS, Choi YB, Scheiffele P, Bailey C, Kandel ER, Kim JH. Neuroligin-1 is required for normal expression of LTP and associative fear memory in the amygdala of adult animals. Proc Natl Acad Sci U S A. (* Equal contribution) 2008 Jun 25;105(26):9087-9092.
8. Jun DJ, Kim J, Jung SY, Song R, Noh JH, Park YS, Ryu SH, Kim JH, Kong YY, Chung JM, Kim KT. Extracellular ATP mediates necrotic cell swelling in SN4741 dopaminergic neurons through P2X7 receptors. J Biol Chem. 2007 Dec 28;282(52):37350-8.
9. Kim HS, Choi Y, Shin KY, Joo Y, Lee YK, Jung SY, Suh YH, Kim JH. Swedish amyloid precursor protein mutation increases phosphorylation of eIF2alpha in vitro and in vivo. J Neurosci Res. 2007 May 15;85(7):1528-37.
10. Xu Y, Kim HS, Joo Y, Choi Y, Chang KA, Park CH, Shin KY, Kim S, Cheon YH, Baik TK, Kim JH, Suh YH. Intracellular domains of amyloid precursor-like protein 2 interact with CP2 transcription factor in the nucleus and induce glycogen synthase kinase-3beta expression. Cell Death Differ. 2007 Jan;14(1):79-91.

Division of Molecular & Life Sciences| POSTECH