Abstract
We have proposed that short (<0.5 s), high-frequency (~50 kHz) ultrasonic vocalizations ('50-kHz USVs') index a positive affective state in adult rats, because they occur prior to rewarding social interactions (i.e., rough-and-tumble play, sex). To evaluate this hypothesis in the case of nonsocial stimuli, we examined whether rats would make increased 50-kHz USVs in places associated with the administration of rewarding pharmacological compounds [i.e., amphetamine (AMPH) and morphine (MORPH)]. In Experiment 1, rats made a greater percentage of 50-kHz USVs on the AMPH-paired side of a two-compartment chamber than on the vehicle-paired side, even after statistical correction for place preference. In Experiment 2, rats made a higher percentage of 50-kHz USVs on the MORPH-paired side than on the vehicle-paired side, despite nonsignificant place preference. These findings support the hypothesis that 50-kHz USVs mark a positive affective state in rats and introduce a novel and rapid marker of pharmacological reward. Copyright (C) 1999 Elsevier Science Inc.
Original language | English (US) |
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Pages (from-to) | 639-643 |
Number of pages | 5 |
Journal | Physiology and Behavior |
Volume | 66 |
Issue number | 4 |
DOIs | |
State | Published - Jun 1999 |
Keywords
- Amphetamine
- Morphine
- Rat
- Reward
- Vocalization
ASJC Scopus subject areas
- Experimental and Cognitive Psychology
- Behavioral Neuroscience