Role of GPR37 in cognitive dysfunction in a mouse model of neuropathic pain / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of G-protein coupled receptor 37 (GPR37) in cognitive dysfunction in a mouse model of neuropathic pain.Methods:SPF-grade healthy male C57BL/6 mice and GPR37 knockout (GPR37-KO) mice, aged 3 months, with a body weight of approximately 20 g, were divided into 4 groups ( n=6 each) using a random number table method: control group (Con group), neuropathic pain group (NPP group), GPR37-KO+ control group (GPR37-KO Con group) and GPR37-KO+ neuropathic pain group (GPR37-KO NPP group). The mouse model of neuropathic pain was established by ligation of the sciatic nerve. The thermal paw withdrawal latency (TWL) and mechanical paw withdrawal threshold (MWT) were measured at 7 days after surgery. The open field test and Morris water maze test were performed at 28 days after surgery. The mice were subsequently sacrificed, and the medial prefrontal cortex (mPFC) was obtained for determination of the level of phosphorylated calcium/calmodulin-dependent protein kinase Ⅱ(p-CAMKⅡ) and expression of brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD-95). Results:Compared to Con group, no significant changes were found in the parameters in GPR37-KO Con group ( P>0.05), and TWL was significantly shortened, MWT was decreased, the time the animal spent in central area was prolonged and the platform-crossing times were increased in the open field test, and the escape latency was prolonged and platform-crossing times were decreased in the Morris water maze test, and the expression of p-CAMKⅡ, BDNF and PSD-95 in the mPFC was down-regulated in NPP group ( P<0.05). Compared with NPP group, TWL was significantly shortened, MWT was decreased, the time the animal spent in central area was prolonged and the platform-crossing times were increased in the open field test, and the escape latency was prolonged and platform-crossing times were decreased in the Morris water maze test, and the expression of p-CAMKⅡ, BDNF and PSD-95 in the mPFC was down-regulated in GPR37-KO NPP group ( P<0.05). Conclusions:GPR37 is involved in the development of cognitive dysfunction in mice with neuropathic pain, and the mechanism may be related to its modulation of synaptic plasticity.