ABSTRACT
Objective To observe the local field potential activity of dorsomedial and dorsolater striatal (STR) neurons in rats with exercise-induced fatigue,so as to explore the regional characteristics of those neurons.Methods Thirty-six male Wistar rats were randomly divided into a control group(CG),a single fatigue group(SFG)and a repeated fatigue group(RFG),each of 12.The exercise-induced fatigue model was established according to a load-increasing treadmill running protocol.The CG did not do any treadmill running,SFG finished one-time exhaustive exercise while the RFG repeated exhaustive exercise 6 times.The extracellular glass microelectrode technique was used to record the spontaneous firing of dorsomedial(n=6)and dorsolateral(n=6)STR neurons in vivo to observe the discharging frequency,characteristics and types.Results (1)Spontaneous firing frequencies of striatal neurons in SFG were significantly higher than those of CG(P＜0.01),while those of RFG were significantly lower than SFG.(2) After repeated fatigues,there were significant decreases in the irregular firing pattern and significant increase in the explosive firing of striatal neurons compared with CG(P＜0.05).(3)After the single fatigue and repeated fatigue,the discharging frequency of dorsomedial medium spiny-like neurons increased significantly(P＜0.05),and that after repeated fatigue significantly higher than that of the dorsolateral(P＜0.01).The discharge frequency of the dorsomedial and dorsolateral fast-spiking neurons decreased significantly after repeated fatigues.The discharge frequency of dorsolateral large aspiny-like neurons of RFG was significantly higher than SFG,while that of the latter was significantly lower than CG(P＜0.05).Conclusions (1)Striatal neurons mediate exercise-induced fatigue and present regional characteristics,which might be due to dorsomedial and dorsolateral striatal neurons receiving different types of projection neurons.(2) Striatal fast-spiking neurons may play an important role in mediating the exercise-induced fatigue.