Ventrolateral periaqueductal gray metabotropic glutamate receptor subtypes 7 and 8 mediate opposite effects on cardiosomatic motor reflex in rats
- VernacularTitle:中脑导水管周围灰质腹外侧区促代谢型谷氨酸受体亚型7和8对大鼠心脏-躯体运动反射的双向调节作用
- Author:
Na SUN
1
;
Lingheng KONG
;
Ligang NIU
;
Juanxia ZHU
;
Yan XU
;
Jianqing DU
Author Information
1. 西安医学院基础医学部
- Keywords:
ventrolateral periaqueductal gray;
rostroventral medulla;
cardiosomatic motor reflex;
metabotropic glutamate receptor 7;
metabotropic glutamate receptor 8;
electromyogram
- From:
Journal of Southern Medical University
2014;(1):8-13
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the role of ventrolateral periaqueductal gray (VL-PAG) metabotropic glutamate receptors subtype 7 and 8 (mGluR 7/8) in descending modulation of cardiosomatic motor reflex (CMR) in rats. Methods AMN082 (agonist of mGluR 7) and DCPG (agonist of mGluR 8) were injected into the VL-PAG of a rat model of CMR to observe their effects in modulating CMR. The raphe magnus nucleus (NRM) or the gigantocellular reticular nucleus (Gi) was then damaged, and the changes in VL-PAG descending modulation were observed. Results Selective activation of mGluR 7 of the VL-PAG by AMN082 obviously facilitated capsaicin (CAP)-induced CMR (P<0.05), which was suppressed by DCPG-induced mGluR 8 activation (P<0.05). These facilitatory or inhibitory effects were completely reversed by group III mGluR antagonist MSOP. Damaging the NRM of VL-PAG main relay nucleus did not significantly affect the facilitatory effect produced by AMN082 microinjection (P>0.05), but partially attenuated the inhibitory effect of DCPG microinjection (P<0.05). Both the facilitatory effect of AMN082 and the inhibitory effect of DCPG were reduced obviously after bilateral Gi damage (P<0.05). Conclusion VL-PAG mGluR 7 and mGluR 8 mediate biphasic regulation of CMR in rats probably through activation of different sub-nuclei and different neurons in the rostroventral medulla.
