Aceves_2011_Learn.Mem_18_764

Reference

Title : Bidirectional plasticity in striatonigral synapses: a switch to balance direct and indirect basal ganglia pathways - Aceves_2011_Learn.Mem_18_764
Author(s) : Aceves JJ , Rueda-Orozco PE , Hernandez-Martinez R , Galarraga E , Bargas J
Ref : Learn Mem , 18 :764 , 2011
Abstract :

There is no hypothesis to explain how direct and indirect basal ganglia (BG) pathways interact to reach a balance during the learning of motor procedures. Both pathways converge in the substantia nigra pars reticulata (SNr) carrying the result of striatal processing. Unfortunately, the mechanisms that regulate synaptic plasticity in striatonigral (direct pathway) synapses are not known. Here, we used electrophysiological techniques to describe dopamine D(1)-receptor-mediated facilitation in striatonigral synapses in the context of its interaction with glutamatergic inputs, probably coming from the subthalamic nucleus (STN) (indirect pathway) and describe a striatonigral cannabinoid-dependent long-term synaptic depression (LTD). It is shown that striatonigral afferents exhibit D(1)-receptor-mediated facilitation of synaptic transmission when NMDA receptors are inactive, a phenomenon that changes to cannabinoid-dependent LTD when NMDA receptors are active. This interaction makes SNr neurons become coincidence-detector switching ports: When inactive, NMDA receptors lead to a dopamine-dependent enhancement of direct pathway output, theoretically facilitating movement. When active, NMDA receptors result in LTD of the same synapses, thus decreasing movement. We propose that SNr neurons, working as logical gates, tune the motor system to establish a balance between both BG pathways, enabling the system to choose appropriate synergies for movement learning and postural support.

PubMedSearch : Aceves_2011_Learn.Mem_18_764
PubMedID: 22101179

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Citations formats

Aceves JJ, Rueda-Orozco PE, Hernandez-Martinez R, Galarraga E, Bargas J (2011)
Bidirectional plasticity in striatonigral synapses: a switch to balance direct and indirect basal ganglia pathways
Learn Mem 18 :764

Aceves JJ, Rueda-Orozco PE, Hernandez-Martinez R, Galarraga E, Bargas J (2011)
Learn Mem 18 :764