Deficient sensorimotor gating induced by selective breeding in rats is improved by entopeduncular nucleus lesions

Deficient prepulse inhibition (PPI) of startle reflects disturbed sensorimotor gating found in certain neuropsychiatric disorders, such as Tourette's syndrome, ADHD, Huntington's and schizophrenia. We here tested, whether lesions of the entopeduncular nucleus (EPN) would improve a PPI-deficit induced by selective breeding. Rats with breeding induced high and low expression of PPI were stereotaxically microinjected with ibotenate (0.2 microg in 0.3 microl phosphate buffered saline) or vehicle into the EPN and two weeks later tested for PPI of the acoustic startle response (ASR) and motor activity. Lesions of the EPN counteracted the breeding-induced PPI-deficit and reduced ASR in the PPI low group without affecting their motor activity. In the PPI high group EPN lesions did not affect PPI, ASR, and motor activity. This work indicates an important role of the EPN in the modulation of sensorimotor gating. Additionally, PPI low rats may provide a non-pharmacological model that can be used to develop new therapeutic strategies for neuropsychiatric disorders.