TY - JOUR
T1 - Elevation of GABA levels in the globus pallidus disinhibits the thalamic reticular nucleus and desynchronized cortical beta oscillations
AU - Villalobos, Nelson
AU - Almazán-Alvarado, Salvador
AU - Magdaleno-Madrigal, Victor Manuel
N1 - Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
N2 - The external globus pallidus (GP) is a GABAergic node involved in motor control regulation and coordinates firing and synchronization in the basal ganglia–thalamic–cortical network through inputs and electrical activity. In Parkinson's disease, high GABA levels alter electrical activity in the GP and contribute to motor symptoms. Under normal conditions, GABA levels are regulated by GABA transporters (GATs). GAT type 1 (GAT-1) is highly expressed in the GP, and pharmacological blockade of GAT-1 increases the duration of currents mediated by GABA A receptors and induces tonic inhibition. The functional contribution of the pathway between the GP and the reticular thalamic nucleus (RTn) is unknown. This pathway is important since the RTn controls the flow of information between the thalamus and cortex, suggesting that it contributes to cortical dynamics. In this work, we investigated the effect of increased GABA levels on electrical activity in the RTn by obtaining single-unit extracellular recordings from anesthetized rats and on the motor cortex (MCx) by corticography. Our results show that high GABA levels increase the spontaneous activity rate of RTn neurons and desynchronize oscillations in the beta frequency band in the MCx. Our findings provide evidence that the GP exerts tonic control over RTn activity through the GP–reticular pathway and functionally contributes to cortical oscillation dynamics.
AB - The external globus pallidus (GP) is a GABAergic node involved in motor control regulation and coordinates firing and synchronization in the basal ganglia–thalamic–cortical network through inputs and electrical activity. In Parkinson's disease, high GABA levels alter electrical activity in the GP and contribute to motor symptoms. Under normal conditions, GABA levels are regulated by GABA transporters (GATs). GAT type 1 (GAT-1) is highly expressed in the GP, and pharmacological blockade of GAT-1 increases the duration of currents mediated by GABA A receptors and induces tonic inhibition. The functional contribution of the pathway between the GP and the reticular thalamic nucleus (RTn) is unknown. This pathway is important since the RTn controls the flow of information between the thalamus and cortex, suggesting that it contributes to cortical dynamics. In this work, we investigated the effect of increased GABA levels on electrical activity in the RTn by obtaining single-unit extracellular recordings from anesthetized rats and on the motor cortex (MCx) by corticography. Our results show that high GABA levels increase the spontaneous activity rate of RTn neurons and desynchronize oscillations in the beta frequency band in the MCx. Our findings provide evidence that the GP exerts tonic control over RTn activity through the GP–reticular pathway and functionally contributes to cortical oscillation dynamics.
KW - Beta band
KW - Globus pallidus
KW - Motor control
KW - Reticular thalamic nucleus
KW - Synchronization
KW - Tonic inhibition
UR - http://www.scopus.com/inward/record.url?scp=85135070528&partnerID=8YFLogxK
U2 - 10.1186/s12576-022-00843-3
DO - 10.1186/s12576-022-00843-3
M3 - Artículo
C2 - 35896962
AN - SCOPUS:85135070528
SN - 1880-6546
VL - 72
JO - Journal of Physiological Sciences
JF - Journal of Physiological Sciences
IS - 1
M1 - 17
ER -