Purpose: To assess the relationship between GABAA receptor in rats's medulla and injury of rats's trigeminal nerve by using real-time polymerase chain reaction(PCR).
Methods: Twenty SD rats were divided into four groups randomly, five rats in each group. Group A and group C were surgical groups, Group B and group D were sham surgical groups. In the surgical group, right unilateral chronical constriction injury(CCI) of rat was produced by placing loose chromic gut ligature around the infraorbital nerve(ION). In the sham surgical group, the ION was only exposed using the same procedure but not ligated. Mechanical response threshold was observed before operation and 3, 6, 9, 12, 15 days after operation. Medullas of rats in group A and B were taken to measure the quantity of GABA(Aalpha1),GABA(Aalpha2),GABA(Aalpha3) receptor by real-time PCR 9 days after operation, and medullas of rats in group C and D were done 15 days after operation. The data were analysed by Students's t test by SAS6.12 software package.
Results: Compared with the sham surgical group, an allodynia to mechanical stimulation on the territory of ligated ION was found from the 9th to 15th day after operation in the surgical group(P<0.05).There was no difference in GABA(Aalpha1) receptor, GABA(Aalpha2) receptor, GABA(Aalpha3) receptor between group A and group C, also there was no difference in GABA(Aalpha1) receptor, GABA(Aalpha2) receptor, GABA(Aalpha3) receptor between group B and group D.
Conclusions: CCI-ION can result in trigeminal neuralgia on rat. Trigeminal neuralgia of rat may not be associated with GABA(Aalpha1) receptor, GABA(Aalpha2) receptor and GABA(Aalpha3) receptor.