Ultrasonic vocalisations explain unexpected effects on pre-pulse inhibition responses in rats chronically pre-treated with phencyclidine.
Beth Tunstall, Simon Beckett, Rob Mason
Behavioural Brain Research September 14, 2009 DOI: 10.1016/j.bbr.2009.03.035 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Sample size | 10 |
| Population | Male juvenile Sprague-Dawley rats |
| Interventions | Phencyclidine (PCP) saline |
| Dose | PCP 5 mg/kg i.p.; saline 1 ml/kg i.p. |
| Duration | 14-day treatment; PPI and USVs recorded on days 16 and 19 |
| Key findings | PCP-treated rats showed decreased PPI on day 16 versus controls, an effect reversed on day 19. USV changes in controls on day 19 (longer duration and latency, fewer calls, shorter calling period) were interpreted as heightened anxiety from inadvertent fear conditioning, while stable USVs in PCP-treated rats were interpreted as reflecting working-memory impairment from chronic PCP. The authors suggest USVs are a valuable additional measure during PPI testing. |
Abstract
Deficits in pre-pulse inhibition (PPI-indicative of psychosis in humans) can be replicated in rats using the NMDA receptor antagonist phencyclidine (PCP). Ultrasonic vocalisations (USVs) produced by rats in response to acoustic startle are indicative of heightened anxiety; here we tested the predictive validity of USVs as an indicator of PPI. Male juvenile Sprague-Dawley rats (n=10) were treated for 14 days with either PCP (5mg/kg i.p.) or saline controls (1 ml/kg i.p.). PPI responses and USVs were recorded on days 16 and 19. PCP-treated rats showed decreased PPI performance on day 16 compared to controls; an observation that was unexpectedly reversed on day 19. Call parameters indicated that both treatment groups experienced similar levels of anxiety in response to the PPI paradigm on day 16. On day 19, the controls showed increased call duration and latency to onset (LtO) of calling, but decreased in the total number of calls produced compared to day 16. The calling period was significantly reduced compared to PCP-treated animals on say 19, whilst the LtO and duration were significantly increased. These changes were considered indicative of heightened levels of anxiety, most likely due to inadvertent fear conditioning (supported by reduced PPI performance) acquired during PPI testing. In contrast, the stability of USV characteristics emitted by PCP treated animals likely signified the detrimental effects of chronic PCP treatment on working memory. These results suggest that USVs are a valuable additional measure during PPI testing, helping to explain the unexpected results from our control group.
Citations in the library
Cited by 2
- Could psychedelic drugs have a role in the treatment of schizophrenia? Rationale and strategy for safe implementation. Molecular Psychiatry 2023
- Effects of the phencyclidine model of schizophrenia and nicotine on total and categorized ultrasonic vocalizations in rats Behavioural Pharmacology June 1, 2016
Cites 10
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and 5 more in the library