EN
Numerous studies showed that occurrence of hippocampal theta rhythm is critically dependent on the integrity of a number structures localized at the level of brainstem and diencephalon. In detailed electrophysiological studies, conducted on anesthetized rats, we demonstrated that the posterior hypothalamic area (PHa), is not only a modulator of hippocampal formation theta but also could generate theta activity independently. The most effective areas in generation of examined EEG pattern were the supramammillary and posterior hypothalamic nuclei. Pharmacological manipulation reviled that PHa theta activity had a cholinergic (muscarinic) profile. Local injection of orexin A and B never induced theta activity in PHa. Finally, we showed that mineralocorticoid receptor but not gap junction play crucial role in generation of the posterior hypothalamic theta rhythm. Studies supported by NCN grant no. 2011/01/B/NZ4/00373.