TY - JOUR
T1 - Distinct populations of motor thalamic neurons encode action initiation, action selection, and movement vigor
AU - Gaidica, Matt
AU - Hurst, Amy
AU - Cyr, Christopher
AU - Leventhal, Daniel K.
N1 - Publisher Copyright:
© 2018 the authors.
PY - 2018/7/18
Y1 - 2018/7/18
N2 - Motor thalamus (Mthal) comprises the ventral anterior, ventral lateral, and ventral medial thalamic nuclei in rodents. This subcortical hub receives input from the basal ganglia (BG), cerebellum, and reticular thalamus in addition to connecting reciprocally with motor cortical regions. Despite the central location of Mthal, the mechanisms by which it influences movement remain unclear. To determine its role in generating ballistic, goal-directed movement, we recorded single-unit Mthal activity as male rats performed a two-alternative forced-choice task. A large population of Mthal neurons increased their firing briefly near movement initiation and could be segregated into functional groups based on their behavioral correlates. The activity of “initiation” units was more tightly locked to instructional cues than movement onset, did not predict which direction the rat would move, and was anticorrelated with reaction time (RT). Conversely, the activity of “execution” units was more tightly locked to movement onset than instructional cues, predicted which direction the rat would move, and was anticorrelated with both RT and movement time. These results suggest that Mthal influences choice RT performance in two stages: short latency, nonspecific action initiation followed by action selection/invigoration. We discuss the implications of these results for models of motor control incorporating BG and cerebellar circuits.
AB - Motor thalamus (Mthal) comprises the ventral anterior, ventral lateral, and ventral medial thalamic nuclei in rodents. This subcortical hub receives input from the basal ganglia (BG), cerebellum, and reticular thalamus in addition to connecting reciprocally with motor cortical regions. Despite the central location of Mthal, the mechanisms by which it influences movement remain unclear. To determine its role in generating ballistic, goal-directed movement, we recorded single-unit Mthal activity as male rats performed a two-alternative forced-choice task. A large population of Mthal neurons increased their firing briefly near movement initiation and could be segregated into functional groups based on their behavioral correlates. The activity of “initiation” units was more tightly locked to instructional cues than movement onset, did not predict which direction the rat would move, and was anticorrelated with reaction time (RT). Conversely, the activity of “execution” units was more tightly locked to movement onset than instructional cues, predicted which direction the rat would move, and was anticorrelated with both RT and movement time. These results suggest that Mthal influences choice RT performance in two stages: short latency, nonspecific action initiation followed by action selection/invigoration. We discuss the implications of these results for models of motor control incorporating BG and cerebellar circuits.
KW - Basal ganglia
KW - Cerebellum
KW - Motor thalamus
KW - Movement initiation
KW - Movement vigor
KW - Parkinson disease
UR - http://www.scopus.com/inward/record.url?scp=85051086394&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.0463-18.2018
DO - 10.1523/JNEUROSCI.0463-18.2018
M3 - Article
C2 - 29934350
AN - SCOPUS:85051086394
SN - 0270-6474
VL - 38
SP - 6563
EP - 6573
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 29
ER -