[Effect of ablation of the septum pellucidum on the marking of time intervals].

It is shown that preliminary ablation of the septum lucidum (the rat group II) leads to a considerable (up to 1000 presentations) and prolonged (up to one year) worsening of the elaboration of time intervals estimation, as compared to intact animals and does not significantly influence the conditioned reflexes to time stabilized before the operation (the rat group I). The great worsening of time intervals estimation is due to disturbance of the very mechanism of the reflex to time. Differences are discussed between the two groups of the operated rats. The septum ablation does not affect the state of conditioned reflexes to present stimuli. In the greater part of the postoperative rats a lowering of alimentary motivation is observed that may be secondarily accompanied by a disturbance of time intervals estimation.