The functional importance of cerebral noradrenergic processes for the activating action of nootropic drugs in the behavioural despair test in mice.

The influence of substances with a known modifying effect on cerebral noradrenergic transmission processes on the activating effect of the nootropics piracetam, pyritinol, meclofenoxat, methylglucamine orotate and dihydroergotoxine in comparison to desipramine and d-amphetamine in the behavioural despair test was investigated in mice. Clonidine, an agonist of presynaptic alpha-adrenoceptor, and prazosin, a postsynaptic alpha-adrenoceptor blocker, in doses without own effect on the swimming behaviour counteracted the activating effect of nootropics in the behaviour despair test. On the other hand, yohimbine, a presynaptic alpha-adrenoceptor blocker, resulting itself in activation, did not change the effect of piracetam additionally. The results confirm the functional importance of noradrenergic processes for the state of immobility and support the possible participation of an influence on the cerebral noradrenergic system in the mechanisms of action of nootropic drugs.