Comparison of electrophysiological properties of two types of pre-sympathetic neurons intermingled in the hypothalamic paraventricular nucleus
10.4142/jvs.2018.19.4.483
- Author:
Yiming SHEN
1
;
Seong Kyu HAN
;
Pan Dong RYU
Author Information
1. Department of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute of Veterinary Science, Seoul National University, Seoul 08826, Korea. pdryu@snu.ac.kr
- Publication Type:Original Article
- Keywords:
action potential;
inhibitory postsynaptic current;
patch-clamp techniques;
rostral ventrolateral medulla;
spinal cord lateral horn
- MeSH:
Action Potentials;
Animals;
Fires;
Horns;
Inhibitory Postsynaptic Potentials;
Membrane Potentials;
Neurons;
Paraventricular Hypothalamic Nucleus;
Patch-Clamp Techniques;
Spinal Cord;
Spinal Cord Lateral Horn
- From:Journal of Veterinary Science
2018;19(4):483-491
- CountryRepublic of Korea
- Language:English
-
Abstract:
The hypothalamic paraventricular nucleus (PVN) contains two types of neurons projecting to either the rostral ventrolateral medulla (PVN(RVLM)) or the intermediolateral horn (IML) of the spinal cord (PVN(IML)). These two neuron groups are intermingled in the same subdivisions of the PVN and differentially regulate sympathetic outflow. However, electrophysiological evidence supporting such functional differences is largely lacking. Herein, we compared the electrophysiological properties of these neurons by using patch-clamp and retrograde-tracing techniques. Most neurons (>70%) in both groups spontaneously fired in the cell-attached mode. When compared to the PVN(IML) neurons, the PVN(RVLM) neurons had a lower firing rate and a more irregular firing pattern (p < 0.05). The PVN(RVLM) neurons showed smaller resting membrane potential, slower rise and decay times, and greater duration of spontaneous action potentials (p < 0.05). The PVN(RVLM) neurons received greater inhibitory synaptic inputs (frequency, p < 0.05) with a shorter rise time (p < 0.05). Taken together, the results indicate that the two pre-sympathetic neurons differ in their intrinsic and extrinsic electrophysiological properties, which may explain the lower firing activity of the PVN(RVLM) neurons. The greater inhibitory synaptic inputs to the PVN(RVLM) neurons also imply that these neurons have more integrative roles in regulation of sympathetic activity.
