D. Treit et al., ANXIOLYTIC EFFECTS OF SEROTONERGIC INTERVENTIONS IN THE SHOCK-PROBE BURYING TEST AND THE ELEVATED PLUS-MAZE TEST, Behavioural brain research, 54(1), 1993, pp. 23-34
Although serotonergic neural systems have been implicated in the contr
ol of anxiety for a number of years, evidence in favour of this role i
s controversial. The present experiments were designed to further char
acterize the putative role of serotonin (5-HT) in anxiety, using two p
harmacologically validated animal models: the elevated plus-maze and t
he shock-probe burying tests. If the integrity of 5-HT neural systems
is necessary for the expression of 'anxious' behaviors, then disruptio
n of 5-HT systems should produce effects in the plus-maze and shock-pr
obe tests that are similar to those of anxiolytic drugs. In the presen
t experiments, serotonergic function was disrupted in rats, either by
chemical depletion using the synthesis inhibitor p-CPA, by inhibitory
autoreceptor activation using the selective 5-HT1A receptor ligand 8-O
H-DPAT, or by electrolytic lesions of the serotonin-containing, dorsal
raphe nucleus. p-CPA and dorsal raphe lesions produced robust anxioly
tic effects in the elevated plus-maze and the shock-probe burying test
s, whereas 8-OH-DPAT produced anxiolytic effects only in the shock-pro
be burying test, and 'anxiogenic' effects in the elevated plus-maze te
st. Although these results generally support the view that serotonin p
lays a role in the expression of 'anxious' behavior, the opposite effe
cts of 8-OH-DPAT in the two behavioral paradigms suggest that the 5-HT
1A receptor subtype exerts differential control over different types o
f experimental anxiety.