Panic-like escape response elicited in mice by exposure to CO2, but not hypoxia

Publication date: 2 February 2018 Source:Progress in Neuro-Psychopharmacology and Biological Psychiatry, Volume 81 Author(s): Ailton Spiacci, Heloisa H. Vilela-Costa, Ana Beatriz Sant'Ana, Gabriel Gripp Fernandes, Alana Tercino Frias, Glauber S. Ferreira da Silva, José Antunes-Rodrigues, Hélio Zangrossi Exposure to elevated concentrations of CO2 or hypoxia has been widely used in psychiatric research as a panic provoking stimulus. However, the use of these respiratory challenges to model panic-like responses in experimental animals has been less straightforward. Little data is available, from behavioral and endocrine perspectives, to support the conclusion that a marked aversive situation, such as that experienced during panic attacks, was evoked in these animals. We here compared the behavioral responses of male CB57BL/6 mice during exposure to 20% CO2 or 7% O2 and its consequence on plasma levels of corticosterone. We also evaluated whether clinically-effective panicolytic drugs affect the behavioral responses expressed during CO2 exposure. The results showed that whereas hypoxia caused a marked reduction in locomotion, inhalation of CO2-enriched air evoked an active escape response, characterized by bouts of upward leaps directed to the border of the experimental cage, interpreted as escape attempts. Corticosterone levels were increased 30min after either of the respiratory challenges used, but it was higher in the hypoxia group. Chronic (21days), but not acute...
Source: Progress in Neuro Psychopharmacology and Biological Psychiatry - Category: Psychiatry Source Type: research