Minerva Seminar 21.3.2025
Friday 21.3.2025 at 10:00-11:00
Biomedicum Helsinki 1, Meeting room 1, P floor
Strikingly different neurotransmitter release strategies in dopaminergic subclasses
Professor Matthew Grubb
Centre for Developmental Neurobiology
Institute of Psychiatry, Psychology and Neuroscience (IoPPN)
King’s College London, UK
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Dr Matthew Grubb is a professor at Kings College London where he leads his research team. The lab is interested in activity-dependent neuronal maturation, with special emphasis on glomerular circuits in the olfactory bulb and the axon initial segment. Due to his seminal work in axon initial plasticity in past, he will serve as an opponent for David Micinski´s defense after the seminar at 12. Prof. Grubb has been an inaugural Scholar of the FENS-Kavli Network of Excellence for years 2014-2018, now being an active member of the alumni network.
Neuronal function is intimately tied to axodendritic polarity. Neurotransmitter release, for example, is usually the role of the axon. There are widespread exceptions to this rule, however, including many mammalian neuronal types that can release neurotransmitter from their dendrites. In the mouse olfactory bulb, closely related subclasses of dopaminergic interneuron differ markedly in their polarity, with one subtype lacking an axon entirely. These axon-bearing and anaxonic dopaminergic subclasses have distinct developmental profiles and sensory responses, but how their fundamental polarity differences translate to functional outputs remains entirely unknown. Here, we provide anatomical evidence for distinct neurotransmitter release strategies among these closely related dopaminergic subtypes: anaxonic cells release from their dendrites, while axon-bearing neurons release exclusively from their intermittently myelinated axon. These structural differences are linked to a clear functional distinction: anaxonic, but not axon-bearing dopaminergic neurons are capable of self-inhibition. Our findings suggest that variations in polarity can produce striking distinctions in neuronal outputs, and that even closely related neuronal subclasses may play entirely separate roles in sensory information processing.
Prof. Grubb will be the opponent of MSc David Micinski’s PhD thesis “The Actin Cytoskeleton and Axon Initial Segment Function” in the Faculty Biological and Environmental Sciences, University of Helsinki. The public examination will take place in Biomedicum Helsinki 1, lecture hall 3, Haartmaninkatu 8, Friday, March 21st, at 13:00.
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Organisation: Minerva Foundation Institute for Medical Research
Contact person: Pirta Hotulainen, pirta.hotulainen@helsinki.fi