Mechanism of bilateral communication in the suprachiasmatic nucleus

摘要: The central circadian pacemaker of the suprachiasmatic nuclei (SCN) is a bilaterally symmetrical structure. Little known about physiological mechanisms underlying communication between left and right SCN yet degree synchronization neurons can have critical impact on properties system. In this study, we used electrophysiological tools calcium (Ca(2+) ) imaging to examine bilateral signaling in mouse SCN. Electrical stimulation one produced responses contralateral with short delay (approximately 5 ms) Ca(2+) -dependence that are consistent action potential-mediated chemical synaptic transmission. Patch-clamp recordings stimulated cells revealed excitatory postsynaptic inward-currents (EPSCs), which were sufficient magnitude elicit potentials. evoked tetrodotoxin-dependent transients 30% all recorded. responding widely distributed within highest density posterior EPSCs significantly reduced after application glutamate receptor antagonist. Application antagonists for receptors other candidate transmitters inhibited some but overall these was variable. functional assay, electrical phase shifts rhythm frequency multiunit activity These blocked by Taken together, results implicate as transmitter required