Visualization of fast calcium oscillations in the parafascicular nucleus

HYDE J; KEZUNOVIC N; # URBANO FJ; # GARCIA-RILL E # URBANO FJ & GARCIA-RILL E CONTRIBUTED EQUALLY AS LAST AUTHORS

PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY

SPRINGER

Lugar: Berlin; Año: 2013 vol. 465 p. 1327 - 1340

0031-6768

# Urbano FJ & Garcia-Rill E contributed equally as last authors. ------------------ The parafascicular nucleus (Pf) is an ascending target of the pedunculopontine nucleus (PPN) and is part of the non-specific intralaminar thalamus. The PPN, part of the reticular activating system, is mainly involved in waking and rapid eye movement sleep. Gamma oscillations are evident in all Pf neurons and mediated by high threshold voltage-dependent N- and P/Q-type calcium channels. We tested the hypothesis that high-speed calcium imaging would reveal calcium mediated oscillations in synchrony with patch clamp recorded oscillations during depolarizing current ramps. 9 to 19 day old rat Pf neurons (n = 148, dye filled n= 61, control n= 87) were filled with Fura 2, Bis Fura, or Oregon Green BAPTA-1. Calcium transients were generated during depolarizing current ramps and visualized with a high-speed, wide-field fluorescence imaging system. Cells manifested calcium transients with oscillations in both somatic and proximal dendrite fluorescence recordings. Fluorescent calcium transients were blocked with the nonspecific calcium channel blocker, cadmium, or the combination of omega-Agatoxin-IVA (AgA), a specific P/Q-type calcium channel blocker and omega-conotoxin-GVIA (CgTx), a specific N-type calcium channel blocker. We developed a viable methodology for studying high-speed oscillations without the use of multi-photon imaging systems.