A. Fernandezguasti et al., BLOCKADE OF THE ANXIOLYTIC ACTION OF 8-OH-DPAT IN LACTATING RATS, Pharmacology, biochemistry and behavior, 59(1), 1998, pp. 45-50
The anxiolytic action of 8-OH-DPAT (0.125, 0.5, and 0.75 mg/kg, IP, -1
5 min) was evaluated in ovariectomized and 7-day lactating mother rats
. This serotonergic anxiolytic produces a clear reduction in cumulativ
e burying behavior and in freezing time (parameters denoting a reducti
on in anxiety levels) in ovariectomized subjects. However, in 7-day la
ctating mother rats, 8-OH-DPAT lacked its antianxiety effects. Additio
nally, as an extra parameter of the animal's emotionality the number o
f defecation bolus was registered. A reduction in this parameter in ov
ariectomized animals after 8-OH-DPAT (0.5 mg/kg) injection was found.
This effect was also blocked in 7-day lactating rats. None of the dose
s of the compound tested altered the burying behavior latency (a param
eter inversely representing the animal's reactivity). The general ambu
latory behavior of ovariectomized subjects was significantly impaired
at the highest dose (0.75 mg/kg) of 8-OH-DPAT. Lower doses did not alt
er this parameter or the number of times lines are crossed (a paramete
r denoting exploratory activity). Discussion is focused on the relatio
nship between the activity of the serotonergic system and the secretio
n of prolactin in this period. (C) 1998 Elsevier Science Inc.