title: Basal ganglia output to the thalamus: still a paradox.
abstract: The basal ganglia (BG)-recipient thalamus controls motor output but it remains unclear how its activity is regulated. Several studies report that thalamic activation occurs via disinhibition during pauses in the firing of inhibitory pallidal inputs from the BG. Other studies indicate that thalamic spiking is triggered by pallidal inputs via post-inhibitory 'rebound' calcium spikes. Finally excitatory cortical inputs can drive thalamic activity, which becomes entrained, or time-locked, to pallidal spikes. We present a unifying framework where these seemingly distinct results arise from a continuum of thalamic firing 'modes' controlled by excitatory inputs. We provide a mechanistic explanation for paradoxical pallidothalamic coactivations observed during behavior that raises new questions about what information is integrated in the thalamus to control behavior.
authors.affiliation: McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA. Electronic address: jesse.goldberg@cornell.edu.
authors.forename: Jesse H
authors.initials: JH
authors.lastname: Goldberg
authors.forename: Michael A
authors.initials: MA
authors.lastname: Farries
authors.forename: Michale S
authors.initials: MS
authors.lastname: Fee
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001479:Basal Ganglia / Q000502:physiology*; D006801:Humans; D009434:Neural Pathways / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D013788:Thalamus / Q000502:physiology*
keywords: basal ganglia; behavior; cortex; thalamus