Effects of anticholinergic drugs selective for muscarinic receptor subtypes on prepulse inhibition in mice.

The effects of anticholinergic drugs selective for muscarinic receptor subtypes on prepulse inhibition of acoustic startle response were determined in mice. The prepulse inhibition is associated with sensorimotor information processing in the brain. The anticholinergic agent scopolamine (0.

Endomorphin-1, an endogenous mu-opioid receptor agonist, improves apomorphine-induced impairment of prepulse inhibition in mice.

The present study was designed to examine the effects of the endogenous mu-opioid receptor agonist endomorphin-1 on prepulse inhibition (PPI) in mice. Although apomorphine (1mg/kg) produced a marked decrease in PPI, endomorphin-1 (17.5 microg) had no marked effects on PPI or startle amplitude in normal mice.