Our research interest
is to understand regulatory mechanisms of presynaptic excitability and synaptic
transmission in the central nervous system (CNS) during physiological or
pathological conditions (e.g. central demyelination or brain hypoxia-ischemia),
using electrophysiology and imaging techniques. Presynaptic excitability is
crucial for the reliable transmission of neuronal information in the central
nervous systems. However, it is very difficult to study presynaptic
excitability and vesicular glutamate release directly at the CNS nerve
terminals, because the sub-micron size of CNS nerve terminals has precluded
direct recordings. To study presynaptic properties directly, we take advantage
of the calyx of Held, a large nerve terminal that allows direct presynaptic
recordings. Using the calyx of Held synapse, we have studied 1) Fundamental
role of CNS myelination in synaptic functions in the auditory nervous system,
2) Cellular mechanisms of neuronal injury during hypoxia-ischemia, and
3) Cellular mechanisms of auditory processing disorder in premature
Lee SY and Kim JH (2015). Mechanisms underlying presynaptic Ca2+ transient and vesicular glutamate release at a CNS nerve terminal during in vitro ischemia. J Physiol.
doi: 10.1113/JP270060. [Epub ahead of print]
Kim SE, Lee SY, Blanco CS and Kim
JH (2014). Developmental profiles in intrinsic properties and synaptic function of auditory neurons in term or preterm baboon neonates. J. Neurosci. 34:11399-11404
Kim SE, Turkington K, Kushmerick C, Kim JH. Central dysmyelination reduces the temporal fidelity of synaptic transmission and the reliability of postsynaptic firing during high-frequency stimulation. J Neurophysiol. 2013 Oct;110(7):1621-30.
Kim JH, Renden R, von Gersdorff H. Dysmyelination of auditory afferent axons increases the jitter of action potential timing during high-frequency firing. J Neurosci. 2013 May 29;33(22):9402-7.
Kim JH, von Gersdorff H. Suppression of spikes during posttetanic hyperpolarization in auditory neurons: the role of temperature, I(h) currents, and the Na(+)-K(+)-ATPase pump. J Neurophysiol. 2012 Oct;108(7):1924-32.
Kim JH, Kushmerick C, von Gersdorff H. Presynaptic resurgent Na+ currents sculpt the action potential waveform and increase firing reliability at a CNS nerve terminal.. J Neurosci. 2010 Nov 17;30(46):15479-90.