Intracellular mechanisms modulating gamma band activity in the pedunculopontine nucleus (PPN)

• Autores: Luster, Brennon; Urbano Suarez, Francisco Jose; Garcia Rill, Edgar
• Año de publicación: 2016
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: AROUSAL; CA2+ CHANNELS; CAMKII; CAMP-PKA; GAMMA OSCILLATIONS; N-TYPE; P/Q-TYPE
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

The pedunculopontine nucleus is a part of the reticular activating system, and is active during waking and REM sleep. Previous results showed that all PPN cells tested fired maximally at gamma frequencies when depolarized. This intrinsic membrane property was shown to be mediated by high-threshold N- and P/Q-type Ca2+ channels. Recent studies show that the PPN contains three independent populations of neurons which can generate gamma band oscillations through only N-type channels, only P/Q-type channels, or both N- and P/Q-type channels. This study investigated the intracellular mechanisms modulating gamma band activity in each population of neurons. We performed in vitro patch-clamp recordings of PPN neurons from Sprague–Dawley rat pups, and applied 1-sec ramps to induce intrinsic membrane oscillations. Our results show that there are two pathways modulating gamma band activity in PPN neurons. We describe populations of neurons mediating gamma band activity through only N-type channels and the cAMP/PKA pathway (presumed “REM-on” neurons), through only P/Q-type channels and the CaMKII pathway (presumed “Wake-on” neurons), and a third population which can mediate gamma activity through both N-type channels and cAMP/PK and P/Q-type channels and CaMKII (presumed “Wake/REM-on” neurons). These novel results suggest that PPN gamma oscillations are modulated by two independent pathways related to different Ca2+ channel types.
Fil: Luster, Brennon. University of Arkansas for Medical Sciences; Estados Unidos
Fil: Urbano Suarez, Francisco Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina
Fil: Garcia Rill, Edgar. University of Arkansas for Medical Sciences; Estados Unidos