Endocannabinoids and Dopamine Balance Basal Ganglia Output

The entopeduncular nucleus is one of the basal ganglia's output nuclei, thereby controlling basal ganglia information processing. Entopeduncular nucleus neurons integrate GABAergic inputs from the Striatum and the globus pallidus, together with glutamatergic inputs from the subthalamic nucleus. We show that endocannabinoids and dopamine interact to modulate the long-term plasticity of all these primary afferents to the entopeduncular nucleus. Our results suggest that the interplay between dopamine and endocannabinoids determines the balance between direct pathway (striatum) and indirect pathway (globus pallidus) in entopeduncular nucleus output. Furthermore, we demonstrate that, despite the lack of axon collaterals, information is transferred between neighboring neurons in the entopeduncular nucleus via endocannabinoid diffusion. These results transform the prevailing view of the entopeduncular nucleus as a feedforward relay nucleus to an intricate control unit, which may play a vital role in the process of action selection.

Automated summary

The study reveals that dopamine and endocannabinoids interact to modulate the long-term plasticity of the entopeduncular nucleus, affecting the balance of its output pathways. Furthermore, despite the lack of axon collaterals, information within the entopeduncular nucleus can be transferred between neighboring neurons via endocannabinoid diffusion.