[Relationship between the sensitivity to tetraethylammonium and firing patterns of injured dorsal root ganglion neurons].
In order to study the relationship between the firing patterns of injured dorsal root ganglion (DRG) neurons of rat and their sensitivity to tetraethylammonium (TEA), spontaneous activities from single fibers of chronically compressed DRG neurons were recorded. Two patterns of spontaneous activity were found: periodic pattern and non-periodic pattern. These two types of neurons showed different sensitivity to TEA with 27.3% in periodic and 93.2% in non-periodic firing neurons responding to TEA (2 mmol/L) (P<0.01). The responses to TEA of different concentrations were greater in the non-periodic firing neurons than in the periodic firing ones (P<0.01). The responses to TEA became apparent in 5 neurons after their periodic firing pattern was transformed into non-periodic firing pattern through an increase in Ca(2+). The non-periodic interburst interval of the bursting discharge decreased significantly while the periodic burst interspike interval had no response to TEA. The unstable period orbits were found in bursting discharge, indicating deterministic chaos during bursting discharge. It is concluded that non-periodic firing neurons with chaos are more sensitive to TEA than periodic firing neurons.
Yang
H J
HJ
Institute of Neurosciences, The Fourth Military Medical University, Xi an 710032, China.
Hu
S J
SJ
Jian
Z
Z
Wan
Y H
YH
Long
K P
KP
D000818:Animals; D004594:Electrophysiology; D005260:Female; D005727:Ganglia, Spinal / Q000293:injuries / Q000503:physiopathology*; D008297:Male; D009474:Neurons / Q000473:pathology / Q000502:physiology; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D019789:Tetraethylammonium / Q000494:pharmacology*
D026902:Potassium Channel Blockers; D019789:Tetraethylammonium