Vol. 274, Issue 3, R718-R724, March 1998
Taste reactivity responses in rats: influence of sex and the
estrous cycle
Sharon N. D. A.
Clarke and
Klaus-Peter
Ossenkopp
Neuroscience Program and Department of Psychology, University of
Western Ontario, London, Ontario, Canada N6A 5C2
Gonadal
hormones (e.g., estradiol) may regulate feeding by producing a shift in
the taste or palatability of food items. This study examined the impact
of endogenous gonadal hormones on palatability by investigating sex
differences in taste responsivity, as well as the effect of the estrous
cycle on taste responsivity, in a rodent model. In the taste reactivity
test, male and female Long-Evans rats received a brief (1 min)
intraoral infusion of one of three tastants: sucrose (0.3 M), quinine
(0.0003 M), and a sucrose-quinine mixture (0.3 M sucrose and 0.0003 M
quinine). Statistical analyses indicated that female rats tested during
diestrus or proestrus produced significantly more ingestive responses
than did male rats and fewer aversive responses than did both male rats
and female rats tested during estrus or metestrus
(P < 0.05). These results indicate a
sex difference in taste responsivity in the rat that is modulated by
the reproductive status of female rats. This finding implies a role of
gonadal hormones in the regulation of taste responsivity in the rat.
taste reactivity test; ingestive responses; aversive responses; estradiol; ingestive behavior
