In this 3P Seminar

Willemieke Kouwenhoven, postdoc at the University of Montreal, presents on “Vglut2 expression in dopamine neurons contributes to post-lesional striatal reinnervation.”

Benoît Delignat-Lavaud, PhD candidate at the University of Montreal, discusses “Mechanisms of somatodendric dopamine release and its contributions to post-lesional plasticity in a Parkinson’s model”.

Willemieke’s presentation will feature:
A small subset of dopamine neurons in the adult, healthy brain expresses Vglut2, a vesicular glutamate transporter, and thus releases glutamate as a second neurotransmitter in the striatum. This neurochemical phenotype appears to be plastic as exposure to neurotoxins such as 6-OHDA or MPTP, that model certain aspects of Parkinson’s pathophysiology, boosts Vglut2 expression in surviving dopamine neurons. Here we show that this enhanced Vglut2 expression in dopamine neurons drives axonal outgrowth and contributes to dopamine neuron axonal plasticity in the post-lesional brain. This work has been submitted to BioRxiv.

Benoît’s presentation includes:
Dopamine neurons can release DA not just from axon terminals through a classical exocytosis mechanism, but also from their somatodendritic (STD) compartment by a mechanism misunderstood. Here we will address the mechanisms of the STD DA release by using the cyclic voltammetry technique in brain slices. Our results show that this form of release appears to be resilient compared to the axonal release in a 6-OHDA model of Parkinson’s. Since it is believed that STD DA release contributes to motor behaviors, this result invites to evaluate to which degree this peculiar form of release influences the clinical picture in Parkinson’s.