Changes in behavior and ultrasonic vocalizations d

Authors: P J van Zyl J J Dimatelis V A Russell

Publish Date: 2013/12/12

Volume: 29, Issue: 2, Pages: 495-507

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Abstract

Genetic predisposition and stress are major factors in depression The objective of this study was to establish a robust animal model of depression by selecting the appropriate substrain of the WistarKyoto WKY rat and subjecting these rats to the stress of maternal separation during the early stages of development The initial experiment identified WKY/NCrl as the appropriate substrain of WKY to use for the study In the second part of the study depressionlike behavior and ultrasonic vocalizations USVs were recorded in WKY/NCrl and maternally separated WKY/NCrl rats during the course of reversal of depressionlike behavior Wistar rats served as the reference strain In adulthood nonseparated WKY/NCrl maternally separated WKY/NCrl and Wistar rats were injected intraperitoneally with either saline or desipramine 15 mg/kg/day for 15 days and their behavior recorded Desipramine decreased immobility and increased active swimming and struggling behavior of WKY/NCrl in the FST and also decreased their USVs in response to removal of cage mates The USVs in this study appeared to signal an attempt to reestablish social contact with cage mates and provided a measure of social dependence Maternally separated WKY/NCrl rats displayed more anxiety than normally reared WKY/NCrl rats and responded to the anxiolytic effects of desipramine The present findings support the use of WKY/NCrl as an animal model of depression Maternal separation increased the anxietylike behavior of the WKY/NCrl thus providing a robust model to study depression and anxietyrelated behaviorThe authors thank the Institute for the Study of Affective Neuroscience ISAN and the National Research Foundation NRF for financial support as well as Professor Jaak Panksepp Dr Gianni Pavan and Dr Paolo Iacobucci for their invaluable advice on recording USVs We would also like to thanks Mr Charles Harris for advice and construction of equipment as well as the University of Cape Town Animal Unit and Ms Nuraan Ismail for taking care of the animals Any opinion finding and conclusion or recommendation expressed in this material is that of the authors and the NRF does not accept any liability in this regard

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