The serotoninergic system takes part in regulating the nociception and neurotic disturbances, but its role in the development of the neurotic hyperalgia is discussed. After the one day water deprivation the experimental neuros was produced by the collision of drinking and defence motivations in three experimental groups of rats. The procedure repeated during four days. The control was intact. Pain sensitivity was measured using the t ail-flick , the h ot plate and the t ail pinch (by painful behavioural reaction) tests before and after t he collision (during three weeks). Each group of rats received injections of saline, buspirone (I) or mianserine (II) twice a day. All drags (in using doses 2,5 mg/kg) had no pain-relieving effect. In experiment N o 1 the treatment accompanied the c ollision (4 days). It protected from the forming the hyperalgia (especially in the t ail flick test). In experiment N o 2 the treatment was produced after the c ollision (14 days). (II) demonstrated no protecting effect on the manifestation of the algesia in the t ail-flick test that reflect perceptive component painful reaction, (I) had significant influence in all tests. Thus, the decreasing functional activity of the serotoninergic system via presynaptic ingibitory 5-HT1a autoreceptors as (I) or by blocking as (II) 5-HT2-receptors prevents from the forming algesia. The pain manifestation links mainly with 5-HT1a-receptors, 5-HT2 is connected with only emotional component of the algesia.