Chronic stress in Lizards: Studies on the behavior and benzodiazepine receptors in Liolaemus Koslowskyi and Cnemidophorus tergolaevigatus

SOLOAGA, A.; PUETA M.; CRUZ, F. B.; KEMBRO J. M.; MARIN, R. H.

JOURNAL OF EXPERIMENTAL ZOOLOGY PART A-ECOLOGICAL GENETICS AND PHYSIOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2016 vol. 325A p. 713 - 725

1932-5223

Behavioraland physiological adaptive responses of animals facing chronic exposure to asingle stressor may allow them to overcome its negativeeffects for future exposures to similar stressful situations. At chemicallevel, the GABAA/benzodiazepine complex is considered one of themain receptor systems involved in the modulation of stress-induced responses. Here,we describe the behavioral responses of two different lizard species, Liolaemus koslowskyi and Cnemidophorus tergolaevigatus exposed to three potential chronic stressful treatments:a) high temperature, b) forced swimming, and c) simulated predator. Additionally,we aimed to determine in those lizards whether thecentral-type benzodiazepine receptor (CBR; an allosteric modulator site of theGABAA receptor) is related to adaptive responses to those stressfulstimulations. Our results revealed that the simulated predator was the stresscondition that showedthe largest difference in behavioral responsesbetween the two species, resembling previouslydescribed strategies in nature. The basal affinity of CBRs (obtained from undisturbedanimals) showed differences between both species and the simulated predator wasthe only stressor that altered the affinity of CBRs. Whereas L. koslowskyi CBRs showed a decreased receptoraffinity, C. tergolaevigatus showed anincreased receptor affinity in comparison to their respective control groups. Weshow for the first time the effects of different types of stressors uponbehavioral responses and CBR biochemical parameters in two lizard species. Ourfindings suggest a potential GABA/benzodiazepine role in the ability of lizardsto cope with a repeated exposure to a stressful (e.g. predator) condition.