اثر تحریک الکتریکی هسته سجافی خلفی بر خواص پاسخی نورونهای لایه چهار قشر بشکه ای متعاقب محرومیت طولانی مدت

Title

The effects of electrical stimulation of dorsal raphe nucleus on neuronal response properties of layer IV of barrel cortex following long-term sensory deprivation

English Abstract

Using single unit recording, the effect of electrical stimulation of dorsal raphe nucleus (DRN) on response properties of layer IV barrel cortex neurons following long-term sensory deprivation was evaluated. Sensory deprived (SD)and control (unplucked) groups were compared. In the SD group all but the D2 vibrissa were plucked on postnatal day one, and kept plucked for a period of 60 days. The spared D2 principal whisker (PW) and the deprived D1 adjacent whisker (AW) were deflected either singly or simultaneously, with neuronal responses being recorded from layer IV of the D2 barrel cortex. DRN was electrically stimulated at inter-stimulus intervals(ISIs)ranging from 0 to 800ms before whiskers deflection. PW-evoked responses increased in the SD group with DRN electrical stimulation at ISIs 50 and 100 ms, whereas AWevoked responses increased at ISI of 800ms in both groups. Whisker plucking leads to increase in neuronal response of barrel cortex neurons to deflection of the PW and decreased responsiveness to deflection of the AW. DRN stimulation significantly reduced this difference in PW-evoked responses between groups. No response latency changes related to DRN stimulation were observed for PW or AW deflection in either group. Condition test (CT) ratio increased in SD rats, while DRN stimulation did not affect the CT ratio in both groups. The 5-HT2A receptor protein density did not change in barrel cortex of SD group compared to control. Data suggests that DRN electrical stimulation can modulate information processing in the sensory deprived barrel cortex.

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