Early stimulation effects on novelty-induced behavior in two psychogenetically-selected rat lines with divergent emotionality profiles.
The present study shows that postnatal handling (H: consisting of removing the pups from the nest twice daily and placing them individually in plastic cages lined with paper towel for a period of 10 min, between postnatal days 1 and 21) and/or environmental enrichment (E: for a period of 6 months) of Roman high- and low-avoidance (RHA/Verh and RLA/Verh) rats induced long-lasting decreases in emotional reactivity (i.e. reduced defecations in the open field, OF, and hole-board, HB, tests) as well as increases in exploratory behavior (i.e. head-dipping) in a manner dependent upon the rat line (there were 'line x H' and 'line x E' interactions). It is reported for the first time that RHA/Verh rats show more head-dipping behavior than RLA/Verh rats, and that the environmental treatments can increase head-dipping of RLA/Verh animals to the level shown by RHA/Verh rats.
Fernández-Teruel
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A
Department of Pharmacology and Psychiatry, School of Medicine, Autonomous University of Barcelona, Spain.
Escorihuela
R M
RM
Núñez
J F
JF
Gomà
M
M
Driscoll
P
P
Tobeña
A
A
D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D003672:Defecation / Q000502:physiology; D004644:Emotions / Q000502:physiology*; D004777:Environment; D005106:Exploratory Behavior / Q000502:physiology; D005239:Fear / Q000502:physiology; D008297:Male; D009043:Motor Activity / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains