Apomorphine disrupts the inhibition of acoustic startle induced by weak prepulses in rats
- 85 Downloads
Separate experiments conducted in two different laboratories assessed the importance of the prepulse intensity in the ability of apomorphine to reduce prepulse inhibition of acoustic startle responses. Rats were presented with noise bursts alone or noise bursts 100 ms after presentation of prepulse stimuli ranging from 70 to 85 or 90 dB. Throughout testing, the background noise was maintained at 65 dB. In both laboratories, apomorphine markedly decreased the absolute magnitude of prepulse inhibition when the prepulse stimuli were no more than 10 dB above the background. With more intense prepulse stimuli, apomorphine had no significant effect on prepulse inhibition. Hence, apomorphine does not interfere with the inhibitory process which actually mediates prepulse inhibition, but appears to affect the detectability of the prepulse.
Key wordsApomorphine Startle Prepulse inhibition
Unable to display preview. Download preview PDF.
- Carlsson A (1978) Mechanism of action of neuroleptic drugs. In: Lipton MA, DiMascio A, Killam KF (eds), Psychopharmacology: a generation of progress. Raven Press, New York, pp 1057–1070Google Scholar
- Davis M (1988) Apomorphine,d-amphetamine, strychnine and yohimbine do not alter prepulse inhibition of the acoustic startle reflex. Psychopharmacology 95:151–156Google Scholar
- Geyer MA, Mansbach RS, Braff DL (1987) Dopamine agonists and antagonists in an animal model of sensory gating and schizophrenia. Proc Soc Biol Psychiatry, p 156Google Scholar
- Geyer MA, Swerdlow NR, Mansbach RS, Braff DL (1990) Startle response models of sensorimotor gating and habituation deficits in schizophrenia. Brain Res Bull (in press)Google Scholar
- Hoffman HS, Ison JR (1980) Reflex modification in the domain of startle: I. Some empirical findings and their implications for how the nervous system processes sensory input. Psychol Rev 2:175–189Google Scholar
- Leitner DS, Cohen ME (1988) Tectal modulation of acoustic startle in the rat. Soc Neurosci Abstr 14:1100Google Scholar
- Moore BCJ (1982) An introduction to the psychology of hearing. Academic Press, New YorkGoogle Scholar
- Swerdlow NR, Koob GF, Geyer MA, Mansbach RS, Braff DL (1988) A cross-species model of psychosis: mesolimbic dopamine hyperactivity in rats mimics abnormal acoustic startle response in schizophrenics. In: Soubrie P (ed) Animal models of psychiatric disorders. Karger, Basel, pp 1–18Google Scholar