Burke Candace J, Markovina Mariya, Pellis Sergio M, Euston David R
Department of Neuroscience, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada.
Department of Psychology, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.
Brain Sci. 2021 Aug 28;11(9):1142. doi: 10.3390/brainsci11091142.
Rats emit a variety of calls in the 40-80 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 30-40 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 "trill with jump" 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.
大鼠会发出各种频率在40 - 80千赫兹范围内的叫声（50千赫兹的叫声）。虽然这些叫声通常与积极情绪有关，但尚不清楚某些叫声是否会在特定情境中被选择性地使用。为了研究这一点，我们观察了30 - 40日龄雄性大鼠在期待玩耍或食物时发出的超声波叫声，玩耍和食物都是强化刺激。在为期七天的测试中，当大鼠在测试箱中等待玩耍伙伴或食物到来时，记录它们的行为和叫声。设置了对照组以排除食物剥夺和社会隔离的非特异性影响。一般来说，玩耍奖励会导致50千赫兹叫声增加，特别是颤音和“带跳跃的颤音”叫声增加，其他组未观察到这种情况。对食物奖励的期待并未导致任何类型叫声的显著增加，这可能是由于我们研究组大鼠年龄较小。此外，在食物期待研究中被剥夺食物的大鼠总体叫声明显更低，与社会隔离的大鼠相比，叫声类型也有所不同。综合来看，结果表明当大鼠处于社会隔离和/或期待社交接触时，可能会选择性地使用与颤音相关的叫声。
