ABSTRACT
Objective To investigate the effects of 5-hydroxytryptamine-2C subunit receptor (5-HT 2C R)on long-term potentiation (LTP)of V1M region visual cortex of form deprivation adult amblyopia rats. Methods Sixteen two weeks old Sp-argue Dawley rats were randomly divided into normal control group and monocular form deprivation group,with 8 rats in each group. The rats in the normal control group were not given any intervention;the rats in the monocular form deprivation group were sutured the right eye lid to establish the monocular form deprivation amblyopia model. All rats were fed for 6 weeks after establishing the model successfully,then the rats in the two groups were sacrificed and the coronal examination of 400 μm thick cortical brain slices were incubated in artificial cerebrospinal fluid artificial cerebrospinal fluid (ACSF). According to the difference of drugs in ACSF,the visual cortex slices of rats in normal control group were selected as group A;the contralateral visual cortex slices of the deprivation eye were divided into group B,group C,group D and group E;the ipsilateral visual cortex slices of the deprivation eye were divided into group F,group G,group H and group I. The ACSF of group A,B and F did not added any drugs;the ACSF of group C and group G were added with physiological saline;the ACSF of group D and group H were added with 10 μmol · L - 15-hydroxytryptamine hydrochloride;the ACSF of group E and group I were added with 10 μmol·L - 1 SB 242084 and 10 μmol·L - 15-hydroxytryptamine hydrochloride. The electrophysiology experiment was per-formed in all of the visual cortex slices by extracellular microelectrode recording and the visual cortex fidd postsynaptic poten-tial(fPSP)slope of V1M region of the visual cortex was recorded. Results The fPSP in group A,B,C,D,E,F,G,H,I was (198. 1 ± 13. 5)％,(106. 3 ± 8. 3)％,(106. 3 ± 8. 3)％,(157. 1 ± 9. 7)％,(102. 6 ± 4. 7)％,(144. 5 ± 2. 9)％,(144. 5 ± 2. 9)％,(192. 2 ± 8. 6)％ and (129. 7 ± 13. 5)％,respectively. There was statistic difference in fPSP slope of visual cortex a-mong the group A,B,F(P < 0. 001);the fPSP slope of visual cortex of rats in group A was significantly higher than that in the group B and group F(P < 0. 001);the fPSP slope of visual cortex of rats in group B was significantly lower than that in the group F(P < 0. 001). The fPSP slope of visual cortex in group D was significantly higher than that in the group C (t = - 10. 833,P < 0. 001);the fPSP slope of visual cortex in group H was significantly higher than that in the group D and group G(t = - 6. 841,- 10. 616;P < 0. 001). The fPSP slope of visual cortex in group E was significantly lower than that in the group D and group I(t = 11. 872,- 3. 910;P < 0. 001,P < 0. 05);the fPSP slope of visual cortex in group I was signifi-cantly lower than that in the group H(t = 9. 911,P < 0. 001). Conclusion Monocular deprivation can lead to the dysfunction of bilateral visual cortex neurons and 5-hydroxytryptamine hydrochloride can reverse this phenomenon through 5-HT2C R.