The exploratory behaviour of rats in the hole-board apparatus: is head-dipping a valid measure of neophilia?
The exploratory behaviour of laboratory rodents is of interest within a number of areas of behavioural pharmacology. However, how best to measure exploratory behaviour in rodents remains a contentious issue. Many unconditioned tests, such as the open field, potentially confound general locomotor activity with exploration. The hole-board apparatus appears to avoid this confound, as head-dipping into holes in the floor is assumed to be a valid measure of the subject's attraction towards novelty (neophilia). This study aimed to investigate whether head-dipping should be considered a valid measure of neophilia by comparing performance of adult male and female Lister hooded rats on the hole-board task (a) over repeated sessions and (b) when novel objects were absent or present underneath the holes. The results show that head-dipping initially decreased across repeated exposures, while time spent in the aversive central area increased. No change in head-dipping was seen in response to objects being placed underneath the holes. Rather than being a measure of neophilia, these results support the hypothesis that head-dipping represents an escape response, which declines as the subject becomes less fearful. These results are compared with previous studies of repeated exposure to other novel environments.
Brown
Gillian R
GR
Institute of Behavioural and Neural Sciences, School of Psychology, University of St. Andrews, South Street, St. Andrews, Fife KY16 9JP, UK. grb4@st-andrews.ac.uk
Nemes
Christopher
C
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D005106:Exploratory Behavior / Q000502:physiology*; D005260:Female; D006185:Habituation, Psychophysiologic / Q000502:physiology; D019416:Head Movements / Q000502:physiology*; D008297:Male; D011589:Psychology, Experimental / Q000295:instrumentation / Q000379:methods; D051381:Rats