Rat Ultrasonic Vocalizations and Behavioral Neuropharmacology: From the Screening of Drugs to the Study of Disease

Several lines of evidence indicate that rats emit ultrasonic vocalizations (USVs) inresponse to a wide range of stimuli that are capable of producing either euphoric (positive) ordysphoric (negative) emotional states. On these bases, recordings of USVs are extensively used inpreclinical studies of affect, motivation, and social behavior. Rat USVs are sensitive to the effectsof certain classes of psychoactive drugs, suggesting that emission of rat USVs can have relevance notonly to neurobiology, but also to neuropharmacology and psychopharmacology. This reviewsummarizes three types of rat USVs, namely 40-kHz USVs emitted by pups, 22-kHz USVs and50-kHz USVs emitted by young and adult animals, and relevance of these vocalizations to neuropharmacological studies.Attention will be focused on the issues of how rat USVs can be used to evaluate the pharmacological properties ofdifferent classes of drugs, and how rat USVs can be combined with other behavioral models used in neuropharmacology.The strengths and limitations of experimental paradigms based on the evaluation of rat USVs will also be discussed.