However, although pioglitazone cannot ameliorate the irreversible brain damage in fructose-drinking insulin resistance rats, pioglitazone administration indeed rescues learning and memory impairments induced by fructose-drinking, this rescuing effect of pioglitazone on cognition dysfunction is well correlated with its effect on the activities of cholinergic system (AChE and ACh). Here, ACHE is linked to Insulin resistance.