title: Air puff-induced 22-kHz calls in F344 rats.
abstract: Air puff-induced ultrasonic vocalizations in adult rats, termed "22-kHz calls," have been applied as a useful animal model to develop psychoneurological and psychopharmacological studies focusing on human aversive affective disorders. To date, all previous studies on air puff-induced 22-kHz calls have used outbred rats. Furthermore, newly developed gene targeting technologies, which are essential for further advancement of biomedical experiments using air puff-induced 22-kHz calls, have enabled the production of genetically modified rats using inbred rat strains. Therefore, we considered it necessary to assess air puff-induced 22-kHz calls in inbred rats. In this study, we assessed differences in air puff-induced 22-kHz calls between inbred F344 rats and outbred Wistar rats. Male F344 rats displayed similar total (summed) duration of air puff-induced 22 kHz vocalizations to that of male Wistar rats, however, Wistar rats emitted fewer calls of longer duration, while F344 rats emitted higher number of vocalizations of shorter duration. Additionally, female F344 rats emitted fewer air puff-induced 22-kHz calls than did males, thus confirming the existence of a sex difference that was previously reported for outbred Wistar rats. The results of this study could confirm the reliability of air puff stimulus for induction of a similar amount of emissions of 22-kHz calls in different rat strains, enabling the use of air puff-induced 22-kHz calls in inbred F344 rats and derived genetically modified animals in future studies concerning human aversive affective disorders.
authors.affiliation: Center for Animal Research and Education, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan. Electronic address: inagaki@care.nagoya-u.ac.jp.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Inagaki
authors.affiliation: Center for Animal Research and Education, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Sato
mesh_terms: D000388:Air; D000818:Animals; D021461:Animals, Outbred Strains / Q000502:physiology / Q000523:psychology; D004195:Disease Models, Animal; D008297:Male; D010812:Physical Stimulation; D011916:Rats, Inbred F344 / Q000502:physiology / Q000523:psychology*; D017208:Rats, Wistar / Q000502:physiology / Q000523:psychology; D012727:Sex Characteristics; D013018:Sound Spectrography; D013045:Species Specificity; D013315:Stress, Psychological / Q000503:physiopathology; D014465:Ultrasonics; D014828:Vocalization, Animal / Q000502:physiology
keywords: Inbred rat strain; Strain difference; Stress model; Ultrasonic vocalization; Vocal communication