Ricerc@Sapienza

About the issue if the natural encephalic proliferative activities can be infl uenced by the seasonal (thermal and photoperiodic) cyclic fl uctuations in adult earth-dwelling Anamnia and poikilothermal Amniota there is a gap regarding expressly summer season alone in literature reports on autoradiographic studies in frog. The actual study suggests that the brain proliferative pattern in Rana bergeri collected in the wild in summer is intermediate between those previously observed in spring and autumn. This would seem to indicate a proliferative increase from spring to autumn.

The question has arisen if the seasonal cycle, made of temperature and photoperiod variations, might activate proliferation of quiescent stem cells still present in adult brain of some living in fresh water, earth-dwelling Anamnia and heterothermic Amniota. Previously, some authors performed seminal autoradiographic, quantitative observations focused on a handful of adult Rana esculenta specimens which, once caught in nature in spring and autumn, were submitted to temporary artificial hibernation and compared with untreated controls.