Direct pathway of movement

Neuroscience

Prefrontal cortex

Central nervous system

Limbic system

Biology

Indirect pathway of movement

Dopaminergic

Cognition

Basal ganglia

Ventral striatum

Globus pallidus

Ventral tegmental area

Thalamus

Striatum

Dopamine

Substantia nigra

Medium spiny neuron

Optogenetics

eLife

Cortico-basal ganglia-thalamocortical loops are largely conceived as parallel circuits that process limbic, associative, and sensorimotor information separately. Whether and how these functionally distinct loops interact remains unclear. Combining genetic and viral approaches, we systemically mapped the limbic and motor cortico-basal ganglia-thalamocortical loops in rodents. Despite largely closed loops within each functional domain, we discovered a unidirectional influence of the limbic over the motor loop via ventral striatum-substantia nigra (SNr)-motor thalamus circuitry. Slice electrophysiology verifies that the projection from ventral striatum functionally inhibits nigro-thalamic SNr neurons. In vivo optogenetic stimulation of ventral or dorsolateral striatum to SNr pathway modulates activity in medial prefrontal cortex (mPFC) and motor cortex (M1), respectively. However, whereas the dorsolateral striatum-SNr pathway exerts little impact on mPFC, activation of the ventral striatum-SNr pathway effectively alters M1 activity. These results demonstrate an open cortico-basal ganglia loop whereby limbic information could modulate motor output through ventral striatum control of M1.

An open cortico-basal ganglia loop allows limbic control over motor output via the nigrothalamic pathway