Chemogenetic activation of glutamatergic neurons in the motor cortex promotes functional recovery after ischemic stroke in rats.

Ischemic stroke is a major cause of disability and mortality worldwide, while no unequivocally efficacious drug is currently available to treat post-stroke functional impairments. Animal and clinical investigations suggest that the motor cortex stimulation constitutes a particularly promising approach for promoting function recovery after stroke. However, the cell types and mechanisms involved in stimulation-induced recovery are not well understood. Here, we used chemogenetic technique to selectively activate glutamatergic neurons in the primary motor cortex and investigated whether activation of glutamatergic neurons in the primary motor cortex can promote functional recovery after ischemic stroke in rats. The results showed that chemogenetic activation of the motor cortex glutamatergic neurons significantly decreased the neurological deficit scores, as well as significantly increased the grip test scores and the hanging time. Moreover, the glutamatergic neuronal activation also significantly decreased the escape latencies, increased the swimming speed, target quadrant time, and numbers of crossing platform position in the Morris water maze test. These results demonstrate that selective activation of the glutamatergic neurons in primary motor cortex is sufficient to promote functional recovery after ischemic stroke, and may be of importance in understanding the neural cellular mechanisms underlying the motor cortex stimulation-induced functional recovery.