Ganglioside-induced enhancement of behavioral recovery after bilateral lesions of the entorhinal cortex.

Previous research has shown that exogenous gangliosides improve recovery of learned alternation after unilateral lesions of the entorhinal cortex. Since this recovery is thought to depend upon axonal sprouting, it has been hypothesized that ganglioside-induced improvement may be due to enhanced sprouting. The present study examined the effects of ganglioside treatments on learned alternation after bilateral entorhinal lesions. Whereas control rats exhibited a severe impairment postoperatively, ganglioside-treated (50 mg/kg total brain gangliosides; i.m.) rats committed significantly fewer errors and perseverative errors, and reached criterion sooner. The two groups exhibited comparable rates of daily improvement in performance. Since bilateral entorhinal lesions preclude the sprouting which is important for recovery of alternation, the ganglioside-induced improvement observed in the present study appears to be independent of sprouting.