title: Hippocampal theta rhythm induced by rostral pontine nucleus stimulation in the conditions of pedunculopontine tegmental nucleus inactivation.
abstract: Theta rhythm in rat hippocampus occurs during cortical activation in different forms of waking as well as during paradoxical phase of sleep. The multi-level regulatory system of theta, based mainly on cholinergic transmission, includes structures from the forebrain to the medulla. Among them the most important are two reticular nuclei: the pedunculopontine tegmental nucleus (PPN) and rostral pontine tegmental nucleus (RPO). Functional relations between these two nuclei are still unidentified. It is known that cholinergic stimulation of these nuclei with carbachol leads to induction of theta in the hippocampus. Electrical stimulation has the same effect but only when applied to the RPO. In our experiments, performed on urethanized rats, each of these two methods was applied to the RPO with the PPN being inactivated in the contralateral hemisphere. We found that inactivation of the PPN does not suppress theta induced with carbachol microinjection into the RPO, but completely blocks theta induction with electrical stimulation of the RPO. The results suggest the important role of the PPN in theta rhythm generation from brainstem level, depending on the method of theta rhythm induction, i.e. cholinergic or electric stimulation of the RPO.
authors: Department of Animal and Human Physiology, University of Gdańsk, Wita Stwosza 59 St., 80-308 Gdańsk, Poland.
authors: Paweł
authors: P
authors: Matulewicz
authors: Magda
authors: M
authors: Kuśmierczak
authors: Jolanta
authors: J
authors: Orzeł-Gryglewska
authors: Edyta
authors: E
authors: Jurkowlaniec
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D004558:Electric Stimulation / Q000379:methods; D004569:Electroencephalography; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008845:Microinjections / Q000379:methods; D045042:Pedunculopontine Tegmental Nucleus / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012890:Sleep / Q000187:drug effects; D013826:Theta Rhythm / Q000187:drug effects / Q000502:physiology
chemical_list: D002217:Carbachol
keywords: Carbachol; Electrical stimulation; PPN; RPO; Theta