The modulation of 4-aminopyridine sensitive potassium channel to bifurcation scenario of the spontaneous neural firing rhythms / 生理学报
Acta Physiologica Sinica
; (6): 35-41, 2010.
Article
in Chinese
| WPRIM (Western Pacific)
| ID: wpr-337782
Responsible library:
WPRO
ABSTRACT
Neuronal firing is crucial to the information processing in the nervous system. In order to make a further study of bifurcation scenarios, experiments were performed on neural pacemakers formed at the injured site of rat sciatic nerve subjected to chronic ligatures. We chose the conductance of voltage-dependent potassium ion channels as conditional parameter, and the extracellular calcium concentration as bifurcation parameter, to give a demonstration of how the firing pattern of neural pacemaker responses to dual parameter adjusting. Among 28 preparations observed, 21 were insensitive to dual parameter adjusting since no change of bifurcation scenario structure was detected. On the contrary, the residual 7 preparations showed dramatic bifurcation scenario shifting corresponding to different dual parameter configuration. Briefly, when concentration of 4-aminopyridine (4-AP), a voltage-dependent potassium ion channels blocker, was kept at different level and extracellular Ca2+ concentration was decreased gradually, different bifurcation scenarios of firing patterns were exhibited in an identical neural pacemaker. The two-parameter bifurcation scenarios of experimental neural pacemaker with different parameter configuration were also different. The results show that neural firing pattern is different when the parameter configuration is different, and the bifurcation scenario is a fundamental framework to identify the transitions between firing patterns.
Full text:
Available
Database:
WPRIM (Western Pacific)
Main subject:
Periodicity
/
Pharmacology
/
Physiology
/
Sciatic Nerve
/
Wounds and Injuries
/
Action Potentials
/
Potassium Channels
/
4-Aminopyridine
/
Calcium
/
Rats, Sprague-Dawley
Type of study:
Diagnostic study
/
Prognostic study
Limits:
Animals
Language:
Chinese
Journal:
Acta Physiologica Sinica
Year:
2010
Document type:
Article