Rat ultrasonic vocalizations as an index of memory. (10th January 2021)

• Record Type: Journal Article
• Authors: Reyes, Kyrie-Anne E.; Kudva, Priya S.; Heckler, Benjamin; Gonzalez, Angela E.; Sorg, Barbara A.
• Is Part Of: Neuroscience letters. Volume 741(2021)
• Publication Date: 2021-01-10
• Subjects: ANOVA analysis of variance -- CS conditioned stimulus -- FM USVs frequency-modulated ultrasonic vocalizations -- IP intraperitoneal; Fear conditioning -- Memory -- Prazosin -- Reconsolidation -- Ultrasonic vocalizations; Neurology -- Periodicals; Neurology -- Periodicals; Research -- Periodicals; Neurologie -- Périodiques; Neuroanatomie -- Périodiques; Neuropharmacologie -- Périodiques; Neurophysiologie -- Périodiques; Neurology; Periodicals; Electronic journals; 617.48
• DOI: 10.1016/j.neulet.2020.135458
• Languages: English
• ISSNs: 0304-3940

Abstract

Highlights: Rats decrease 50 kHz USVs after fear conditioning. Disrupted reconsolidation is not reflected by 50 kHz USVs, which remain decreased. Abstract: The emission of 50 kHz frequency-modulated ultrasonic vocalizations (FM USVs) in rats has been associated with positive affective states, while a decrease in FM USVs has been associated with anxiety-like states. We tested the hypothesis in male Sprague-Dawley rats that FM USVs would complement measures of aversive memories (decrease in FM USVs) in a conditioned fear task in which we examined extinction or reconsolidation disruption. In Experiment 1, rats were fear conditioned using low-level footshock followed by extinction while monitoring freezing and FM USVs. In Experiment 2, rats were fear conditioned, the alpha-1 antagonist prazosin was used to disrupt reconsolidation of memory, and freezing and FM USVs were measured. Rats fear conditioned with low-level shock showed minimal freezing that rapidly extinguished, despite a persistent decrease in FM USVs throughout extinction. Prazosin reduced freezing in a memory reactivation-dependent manner as expected, but the reduction in FM USVs after fear conditioning remained decreased, suggesting that an affective component of memory was not impacted by prazosin. These findings indicate that FM USVs may be used as an index of fear- or anxiety-like memory, and their measurement could benefit pre-clinical animal models for assessing reduction of aversive memories.