Do cerebellar outputs modulate striatal-dependent motor learning task?

VARANI ANDRÉS P.; MAILHES-HAMON CAROLINE; LÉNA CLÉMENT; POPA DANIELA

Congreso; GDR Neuralet, 8th annual meeting.; 2017

It is well known that the cerebellum is involved in motor learning. However, how cerebellar outputs modulate this behavior remains unclear. We evaluated the role of cerebello-thalamo-cortical network during motor skill learning by using in vivo multi-channels recordings. We observed a decrease in the deep cerebellar nuclei activity during consolidation but not acquisition phase of the motor learning task. Increased cortical (M1 cortex) activity was observed during acquisition phase while thalamic (Intralaminar and motor thalamus) activity increased in all the phases. We also investigated the effects of a specific and transient silencing in the neuronal activity of cerebellar outputs during motor skill learning by using hM4Di-DREADDs (designed receptors exclusively activated by drugs). Our results showed that inhibition of deep cerebellar neurons produced impairment in the beginning of the consolidation phase and then a retrieval effect was observed, suggesting that adaptive mechanisms could compensate the lack of deep cerebellar nuclei activity. In order to inhibit dentate nucleus-intralaminar thalamus and interposed-motor thalamus projections, we combined a CRE-recombinase expressing retrograde canine adenovirus-2 and a floxed hM4Di-DREADD. The results revealed that these projections modulate motor skill learning during consolidation but not acquisition phase. In conclusion, our results indicate that cerebellar outputs participate to consolidation of motor learning.