[Modulation of GABA-activated currents by oxytocin in rat dorsal root ganglion neurons].
Experiments were performed on freshly isolated dorsal root ganglion (DRG) neurons of rat. GABA(A)-activated currents were recorded using the whole-cell patch clamp technique. The majority of the neurons (48/52, 90.5%) were sensitive to GABA (10(  6)~10(  3) mol/L). Application of oxytocin (OT) induced outward membrane responses in 51.3% (20/39) of the neurons, no apparent responses in 43.6% (17/39) and inward responses in 5.1% (2/39). 10(  12), 10(  11), 10(  10) and 10(  9) mol/L OT increased 10(  4) mol/L GABA-activated currents to 24.1+/-7.6% (n=6), 33.4+/-6.9% (n=9), 40.2+/-6.5% (n=13) and 67.2+/-14.8% (n=5), respectively. After preapplication of OT, the Kd value for GABA(A)-activated currents decreased, while the response obtained at the maximum concentration increased. The results suggest that the enhancement of GABA-activated currents by OT may suppress primary sensory transmission by potentiating pre-synaptic inhibition of GABA.
Tan
Z J
ZJ
Department of Physiology, Hubei Medical University, Wuhan 430071, China.
Wei
J B
JB
Li
Z W
ZW
Shao
M
M
Hu
Q S
QS
Peng
B W
BW
D000818:Animals; D000831:Animals, Newborn; D002469:Cell Separation; D004594:Electrophysiology; D005727:Ganglia, Spinal / Q000166:cytology / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000502:physiology; D010121:Oxytocin / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D010121:Oxytocin; D005680:gamma-Aminobutyric Acid