The research interests of Dr. Gladys Ko’s lab are circadian neurobiology and synaptic plasticity. Our primary research program will focus on the circadian regulation of physiology in chick retina. We have found that intrinsic biological clocks not only modulate the apparent affinity of cGMP-gated ion channels, but also regulate voltage-dependent calcium channels (VDCCs) as well as other ion channels. My lab will investigate the signal transduction and cellular mechanisms involved in circadian control of VDCCs, and the potential roles of VDCCs in neurotransmitter (especially melatonin) secretion, synaptic plasticity, and circadian entrainment in photoreceptors. We will also address the roles of other neurotransmitters and neuromodulators (e.g., dopamine and somatostatin), which are secreted from different classes of amacrine cells, in regulating VDCCs and photoreceptor physiology. In the distant future, we will extend our research to examine the bi-directional relationship between the central clock (Suprachiasmatic Nuclei) and retina.
Our second research project will focus on the circadian regulation of synaptic plasticity in the hippocampus. Hippocampus plays an important role in learning and memory, and it receives melatonin inputs from other brain areas. Melatonin has been used to treat sleep disorders as well as epilepsy. However, the detail cellular mechanisms are still not fully understood. We will investigate the circadian phase-dependent modulation of melatonin and the underlying cellular mechanisms in the hippocampus. People joining the lab will use patch-clamp electrophysiological recordings, Western immunoblotting, immunocytochemistry (confocal imaging), transmission electron microscopy (TEM), Quantitative RT-PCR and other molecular techniques in these projects.