The effect of early postnatal hypoxia on the effectiveness of drugs influencing motor behaviour in adult rats.

The effectiveness of drugs affecting aminergic triggered motor behaviour was investigated in adult rats oxygen deprived in the early postnatal life. Offsprings were exposed to hypobaric hypoxia (pO2 = 11.6 kPa) from the 2nd till the 10th postnatal day (10 h per day). Hypoxia exposed animals displayed a significant decrease of the locomotor apomorphine effect as well as of the amphetamine induced stereotyped behaviour. On the other hand, apomorphine stereotypies and the locomotor amphetamine effect proved to be unchanged after postnatal oxygen deprivation. The motility levels achieved after giving lysergic acid diethylamide 30 min before apomorphine administration were found to be considerably higher than after apomorphine alone and similar for both controls and hypoxia exposed animals. After unilateral dopamine injections into the nucleus accumbens no different rotational behaviour was detectable. The deviations in some of their responses to drugs affecting aminergically triggered behaviour in adult rats suggested a decreased behavioural effectiveness of dopamine agonists due to early postnatal hypoxia.