[Reflex time in relation to age and behavioral status studied in postnatal growing rats]

1. The central nervous system of neonatal albino rats showed age specific functional parameters, some of them are comparable with those of human prematures. 2. The reflex times (RT) of the lid closure reflex and of the withdrawal reflex of the foreleg, hindleg and tail were measured during the behavioral states quite sleep, active sleep, and wakefulness of rats between 1st and 20th postnatal day. 3. The RT of the investigated reflexes decreased with age in different degrees. 4. The RT was found to be different in the behavioral states; with increasing age the RT becomes longer in active sleep than in the other states. 5. The reflex time measurement of withdrawal reflexes during different behavioral states should be proved for its applicability as a test for normal brain development in humans newborns.