¹Department of Psychiatry, University of California, San Diego, CA, USA

Correspondence: David Feifel, Department of Psychiatry, UCSD Medical Center, 200 West Arbor Drive, San Diego, CA 92103-8218, USA. Tel: +1 619 543 2485; Fax: +1 619 543 3738; E-mail: dfeifel@ucsd.edu

Received 4 June 2002; Revised 23 September 2002; Accepted 25 September 2002.

Abstract

Prepulse inhibition (PPI) of the startle reflex can be disrupted by drugs that act as agonists at the serotonin (5-HT) 2A receptor, such as DOI, and this effect is blocked by drugs that inhibit 5-HT2A transmission. We tested the effects of systemic administration of PD149163, a neurotensin agonist, on DOI-induced disruption of PPI in Sprague–Dawley rats. PD149163 completely and dose dependently blocked the PPI deficits produced by DOI. These findings suggest that, in addition to their established ability to inhibit dopamine transmission, neurotensin agonists may also inhibit 5-HT2A transmission, a pharmacological feature associated with atypical antipsychotic drugs.