Hsp70 promotes synaptic transmission in brain slices damaged by contact with blood clot.

Neurotrophic and neuroprotective properties of Hsp70 were studied in olfactory cortex slices of hypertensive rats under normal conditions and under influence of autologous blood (blood clot). Under normal conditions, synaptic response in slices depended on Hsp70 amount in medium. Incubation of slices with Hsp70 showed a biphasic effect on electrogenesis in tissue. Hsp70 (from 0.1 to 3.0 μg/ml) stimulated glutamatergic and GABA-ergic receptor activity. An inhibitory action on synaptic response is detected at increased amounts of Hsp70 (>4 μg/ml). Pretreatment with Hsp70 (1 and 10 μg/ml) prevented the irreversible inhibition of bioelectric activity in neurons damaged by autologous blood action and interfered with swelling in slices. Our results indicate that exogenous Hsp70 may play a role in the maintenance of neuronal synaptic functions in normal conditions, and protects electrogenesis of brain tissue in strokes.