Spontaneous voltage oscillations in striatal projection neurons in a rat corticostriatal slice
Por:
Vergara R., Rick C., Hernández-López S., Laville J.A., Guzman J.N., Galarraga E., Surmeier D.J., Bargas J.
Publicada:
1 ene 2003
Resumen:
In a rat corticostriatal slice, brief, suprathreshold, repetitive cortical stimulation evoked long-lasting plateau potentials in neostriatal neurons. Plateau potentials were often followed by spontaneous voltage transitions between two preferred membrane potentials. While the induction of plateau potentials was disrupted by non-NMDA and NMDA glutamate receptor antagonists, the maintenance of spontaneous voltage transitions was only blocked by NMDA receptor and L-type Ca2+ channel antagonists. The frequency and duration of depolarized events, resembling up-states described in vivo, were increased by NMDA and L-type Ca2+ channel agonists as well as by GABAA receptor and K+ channel antagonists. NMDA created a region of negative slope conductance and a positive slope crossing indicative of membrane bistability in the current-voltage relationship. NMDA-induced bistability was partially blocked by L-type Ca2+ channel antagonists. Although evoked by synaptic stimulation, plateau potentials and voltage oscillations could not be evoked by somatic current injection - suggesting a dendritic origin. These data show that NMDA and L-type Ca2+ conductances of spiny neurons are capable of rendering them bistable. This may help to support prolonged depolarizations and voltage oscillations under certain conditions.
Filiaciones:
Vergara R.:
Department of Biophysics, Instituto de Fisiologia Celular UNAM, PO Box 70-253, Mexico City, DF 04510, Mexico
Rick C.:
Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, United States
Hernández-López S.:
Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, United States
Laville J.A.:
Department of Biophysics, Instituto de Fisiologia Celular UNAM, PO Box 70-253, Mexico City, DF 04510, Mexico
Guzman J.N.:
Department of Biophysics, Instituto de Fisiologia Celular UNAM, PO Box 70-253, Mexico City, DF 04510, Mexico
Galarraga E.:
Department of Biophysics, Instituto de Fisiologia Celular UNAM, PO Box 70-253, Mexico City, DF 04510, Mexico
Surmeier D.J.:
Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, United States
Bargas J.:
Department of Biophysics, Instituto de Fisiologia Celular UNAM, PO Box 70-253, Mexico City, DF 04510, Mexico
All Open Access; Green
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