{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T18:09:57Z","timestamp":1790446197445,"version":"4.1.0"},"reference-count":55,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,8,28]],"date-time":"2021-08-28T00:00:00Z","timestamp":1630108800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council of Canada","doi-asserted-by":"publisher","award":["2018-05777"],"award-info":[{"award-number":["2018-05777"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council of Canada","doi-asserted-by":"publisher","award":["2018-03706"],"award-info":[{"award-number":["2018-03706"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000145","name":"Alberta Innovates - Health Solutions","doi-asserted-by":"publisher","award":["Polaris award"],"award-info":[{"award-number":["Polaris award"]}],"id":[{"id":"10.13039\/501100000145","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Brain Sciences"],"abstract":"<jats:p>Rats emit a variety of calls in the 40\u201380 kHz range (50 kHz calls). While these calls are generally associated with positive affect, it is unclear whether certain calls might be used selectively in certain contexts. To examine this, we looked at ultrasonic calls in 30\u201340 day old male rats during the expectation of either play or food, both of which are reinforcing. Behavior and vocalizations were recorded while rats were in a test chamber awaiting the arrival of a play partner or food over seven days of testing. Control groups were included for the non-specific effects of food deprivation and social isolation. Play reward led to an increase in 50 kHz vocalizations, generally, with specific increases in trill and \u201ctrill with jump\u201d calls not seen in other groups. Expectation of food reward did not lead to a significant increase in vocalizations of any type, perhaps due to the young age of our study group. Further, rats that were food deprived for the food expectation study showed markedly lower calls overall and had a different profile of call types compared to rats that were socially isolated. Taken together, the results suggest that trill-associated calls may be used selectively when rats are socially isolated and\/or expecting a social encounter.<\/jats:p>","DOI":"10.3390\/brainsci11091142","type":"journal-article","created":{"date-parts":[[2021,8,29]],"date-time":"2021-08-29T21:45:16Z","timestamp":1630273516000},"page":"1142","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Rat 50 kHz Trill Calls Are Tied to the Expectation of Social Interaction"],"prefix":"10.3390","volume":"11","author":[{"given":"Candace J.","family":"Burke","sequence":"first","affiliation":[{"name":"Department of Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mariya","family":"Markovina","sequence":"additional","affiliation":[{"name":"Department of Psychology, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sergio M.","family":"Pellis","sequence":"additional","affiliation":[{"name":"Department of Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"David R.","family":"Euston","sequence":"additional","affiliation":[{"name":"Department of Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,8,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"961","DOI":"10.1037\/0033-2909.128.6.961","article-title":"Ultrasonic vocalizations as indices of affective states in rats","volume":"128","author":"Knutson","year":"2002","journal-title":"Psychol. 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