Voltage and synaptically activated channels in brainstem preganglionic parasympathetic cardiac neurons
Document Type
Conference Proceeding
Publication Date
12-1-1995
Journal
Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings
Volume
17
Issue
2
Abstract
This report briefly describes the voltage gated and synaptically gated currents in parasympathetic cardiac neurons that originate in the medulla and project to the heart. Fluorescent tracers are used to identify these neurons within an in-vitro slice and patch clamp electrophysiological techniques allow us to control intracellular voltage and characterize the electrophysiology and pharmacology of voltage dependent and post-synaptic ligand gated channels. Depolarization of these neurons to voltages more positive than -50 mV activate tetrodotoxin (TTX) sensitive inward sodium currents, in addition to two types of outward potassium currents. The potassium currents are the I(A) and I(DR) type of potassium channels which are blocked by 4-aminopyridine (4AP) and tetraethylammonium (TEA), respectively. Stimulation of another nucleus, the nucleus tractus solitarius (NTS), which receives cardiovascular sensory information, activates a monosynaptic pathway to these neurons. Glutamate is synaptically released from these NTS neurons which activates both long lasting (>200 ms) N-methyl-D-Aspartate (NMDA) and transient non-NMDA post-synaptic currents in parasympathetic cardiac neurons.
APA Citation
Mendelowitz, D. (1995). Voltage and synaptically activated channels in brainstem preganglionic parasympathetic cardiac neurons. Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings, 17 (2). Retrieved from https://hsrc.himmelfarb.gwu.edu/smhs_pharm_facpubs/866