Behavioral Phenotyping of Rats Selectively Bred for Differential Levels of 50 Khz Ultrasonic Vocalizations
Year: 2006
Type: article
Abstract: In rats, the rates of 20 kHz and 50 kHz ultrasonic vocalizations (USVs) can be used as a selective breeding phenotype and variations in this phenotype can be an indicator of positive affective states and developmental differences.The 50 kHz USV is elicited by positive or rewarding stimuli (e.g., food, sex, drugs of abuse) and therefore can be an indictor of a positive affective state.Conversely, the 20 kHz USV is elicited by aversive stimuli (e.g., foot shock, presence of a predator, social defeat) indicating a negative affective state.In this study, we tested the effect of selectively breeding for 50 kHz USVs on a variety of social / emotional behaviors across the animal's lifespan.These social / emotional measures consisted of observations of pup retrieval latency and maternal care behaviors, measurement of isolation distress calls and conditioned odor preference as pups (age 1-12 days), play behavior, and social investigation as juveniles (age 21-32 days) into adulthood (90+ days of age).Cross fostering was utilized to determine if the differences in behaviors were primarily a result of maternal care or genetic expression.Results indicate that animals selected for low levels of 50 kHz USVs show the greatest alterations in social behaviors compared to the random "control" line animals.The low line animals showed a slight decrease in maternal/pup bonding, increased isolation distress calls, and failed to show a preference for a maternally associated odor, a marginal decrease in dorsal contacts during rough-and-tumble play behavior, and significantly more investigation in the social investigation paradigm after isolate housing.The social behaviors of the high line animals did not consistently vary from the random line animals with the exception of more investigation iv during social port testing.Based on cross fostering results, maternal care does not appear to explain the differences observed in these selectively bred lines.These results provide implications for the study of genetics underlying emotional states, as well as contribute to the research underlying the emotional changes in developmental disorders such as autistic spectrum disorder.v "Laughter seems primarily to be the expression of mere joy or happiness."
Author: Kelley M. Harmon
Institution: Bowling Green State University
Language: English
Subfield: Endocrine and Autonomic Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
Funder: Bowling Green State University
OpenAlex ID: W2598759666