Cerebellar Modulation of Mesolimbic Dopamine Transmission Is Functionally Asymmetrical

Area of Science:

• Neuroscience
• Neurochemistry
• Behavioral Neuroscience

Background:

• Cerebral and cerebellar hemispheres exhibit structural and functional asymmetry.
• Previous research indicates dopamine systems also display lateralization.
• The cerebellum's role in reward and motivation is increasingly recognized.

Purpose of the Study:

• To investigate hemispheric lateralization of dopamine release in the nucleus accumbens (NAc).
• To determine the influence of cerebellar output on mesolimbic dopamine transmission.
• To explore the cerebellum's role in regulating reward pathways.

Main Methods:

• Utilized in vivo fixed potential amperometry with carbon fiber microelectrodes in anesthetized mice.
• Assessed stimulation-evoked dopamine release in the NAc.
• Electrically stimulated the cerebellar dentate nucleus (DN) and medial forebrain bundle (MFB).
• Investigated the effect of contralateral DN inactivation using lidocaine.

Main Results:

• Dopamine release in the NAc did not differ between hemispheres upon MFB stimulation.
• Electrical stimulation of the cerebellar DN evoked significantly greater dopamine release in the right NAc compared to the left.
• Inhibiting the contralateral DN did not alter dopamine release in the NAc.

Conclusions:

• Cerebellar output modulates mesolimbic dopamine transmission, contributing to asymmetric dopamine release.
• Cerebellar dentate nucleus stimulation specifically enhances dopamine release in the contralateral NAc.
• These findings provide a neurochemical basis for the cerebellum's involvement in reward, motivation, and inhibitory control.