Anxiogenic effect of naltrexone in social interaction test in rats
Abstract
AIM: To study the anxiogenic effect of naltrexone (Nal) on the emotional state of rats.
METHODS: The duration of active interaction was measured in the social interaction test in rats.
RESULTS: Without influence on the locomotor activity, Nal (0.1-50 mg.kg-1) dose- and time-dependently decreased the duration of active interaction, which was antagonized by morphine (5 mg.kg-1) or fenclonine (Fen, 150 mg.kg-1 x 3 d) and was enhanced by 5-hydroxytryptophan (5-HTP, 50 mg.kg-1).
CONCLUSIONS: Nal produced anxiety via its blockade of opioid receptors; central opioidergic neurons were involved in the regulation of anxiety through their tonic inhibitions in serotonergic neurons.
Keywords:
METHODS: The duration of active interaction was measured in the social interaction test in rats.
RESULTS: Without influence on the locomotor activity, Nal (0.1-50 mg.kg-1) dose- and time-dependently decreased the duration of active interaction, which was antagonized by morphine (5 mg.kg-1) or fenclonine (Fen, 150 mg.kg-1 x 3 d) and was enhanced by 5-hydroxytryptophan (5-HTP, 50 mg.kg-1).
CONCLUSIONS: Nal produced anxiety via its blockade of opioid receptors; central opioidergic neurons were involved in the regulation of anxiety through their tonic inhibitions in serotonergic neurons.