Dopaminergic Dependency of Cholinergic Pallidal Neurons
Por:
López-Niño J., Padilla-Orozco M., Ortega A., Alejandra Cáceres-Chávez V., Tapia D., Laville A., Galarraga E., Bargas J.
Publicada:
1 ene 2023
Ahead of Print:
1 ago 2023
Categoría:
Neuroscience (miscellaneous)
Resumen:
We employed the whole-cell patch-clamp method and ChAT-Cre mice to study the electrophysiological attributes of cholinergic neurons in the external globus pallidus. Most neurons were inactive, although approximately 20% displayed spontaneous firing, including burst firing. The resting membrane potential, the whole neuron input resistance, the membrane time constant and the total neuron membrane capacitance were also characterized. The current–voltage relationship showed time-independent inward rectification without a “sag”. Firing induced by current injections had a brief initial fast adaptation followed by tonic firing with minimal accommodation. Intensity-frequency plots exhibited maximal average firing rates of about 10 Hz. These traits are similar to those of some cholinergic neurons in the basal forebrain. Also, we examined their dopamine sensitivity by acutely blocking dopamine receptors. This action demonstrated that the membrane potential, excitability, and firing pattern of pallidal cholinergic neurons rely on the constitutive activity of dopamine receptors, primarily D2-class receptors. The blockade of these receptors induced a resting membrane potential hyperpolarization, a decrease in firing for the same stimulus, the disappearance of fast adaptation, and the emergence of a depolarization block. This shift in physiological characteristics was evident even when the hyperpolarization was corrected with D.C. current. Neither the currents that generate the action potentials nor those from synaptic inputs were responsible. Instead, our findings suggest, that subthreshold slow ion currents, that require further investigation, are the target of this novel dopaminergic signaling. © 2023 IBRO
Filiaciones:
López-Niño J.:
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, 04510, Mexico
Padilla-Orozco M.:
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, 04510, Mexico
Ortega A.:
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, 04510, Mexico
Alejandra Cáceres-Chávez V.:
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, 04510, Mexico
Tapia D.:
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, 04510, Mexico
Laville A.:
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, 04510, Mexico
Galarraga E.:
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, 04510, Mexico
Bargas J.:
División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México City, 04510, Mexico
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