Escape-related behaviours in an unstable elevated and exposed environment. I. A new behavioural model of extreme anxiety.
The aim of this study was to validate a new behavioural test for extreme anxiety, designed to elicit unconditioned escape from animals on an unstable, elevated and exposed plus maze. The animals were also run on a standard elevated plus maze, so that well-validated anxiety measures could be compared with the animals' propensity to escape. The first experiment compared the behavioural repertoire of three rat strains; more escape behaviours were elicited from the Sprague Dawleys (SDs) and dark agouti (DAs) than from the hooded listers (HLs) on the unstable maze. Similarly, the SDs and DAs exhibited higher anxiety profiles than the HLs on the standard plus maze. There was a clear correlation, therefore, between the propensity to escape and well-validated anxiety measures. A further group of rats [HLs] was tested on both the unstable and standard plus mazes (Experiment 2) and principal components analyses carried out on all behavioural measures. The extracted factors identified separate and independent factors relating to escape-linked behaviours on the unstable plus maze and anxiety on the standard plus maze. The escape-linked behaviours exhibited on the unstable plus maze appear to reflect a different type of anxiety from that exhibited on the standard plus maze. The bias towards escape behaviours shown by some rats on the unstable plus maze may mimic the chronically hyper-aroused, persistent 'fight/flight' state exhibited by certain categories of anxiety patients, and hence provide a behavioural model of extreme anxiety.
King
S M
SM
University of Oxford, Department of Experimental Psychology, UK. s.king@ucl.ac.uk
D000818:Animals; D001143:Arousal / Q000502:physiology*; D001921:Brain / Q000502:physiology; D004195:Disease Models, Animal; D004924:Escape Reaction / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012931:Social Environment; D013045:Species Specificity