Cholinergic modulation of the mesostriatal pathway

Cholinergic neurotransmission exerts widespread modulation of brain function. The focus of my thesis is to detail the neurophysiological and behavioural function of acetylcholine in the striatum and the dopaminergic midbrain. Using ChAT::cre Long Evans rats I investigate the direct and the indirect connectivity between brainstem and striatum. Using anatomical, electrophysiological and behavioural experiments, I describe a direct projection to the striatum arising from the cholinergic brainstem and also an indirect pathway through the dopaminergic midbrain. I describe anatomical and physiological differences in the modulation of dopaminergic midbrain neurons by cholinergic neurons in the pedunculopontine and the laterodorsal tegmental nucleus. I also show a novel cholinergic pathway to the striatum arising from the brainstem. Based on anatomical, physiological and behavioural results, I show a strong functional modulation of striatum by cholinergic transmission.