Prof. Rafael G. Almeida; Centre for Discovery Brain Sciences (CDBS), University of Edinburgh

• Día: Lunes 15 de julio, de 2024, a las 13:00 h.
• Lugar: Sala Aketxe, Edificio Sede (Junto a Edificio de Biblioteca), Campus Leioa

Organiza: Laboratorio de Neurobiología, Departamento de Neurociencias UPV/EHU, CIBERNED, Achucarro

Non-synaptic neurotransmission mediates axon-oligodendrocyte interactions in vivo – insights from zebrafish

Neurotransmitter release at synapses underpins nervous system function, but neurons also release neurotransmitters elsewhere. The molecular basis and roles of such non-synaptic transmission are poorly understood, and could potentially facilitate direct communication with surrounding glial cells. For example, oligodendrocytes drastically change conduction properties by wrapping axons with myelin, which can be dynamically regulated throughout life in response to neuronal activity. However, how axon-myelin communication occurs in vivo is unclear. We are using the zebrafish model organism to address this, developing novel live reporters of neurotransmitter release and gene-editing techniques to image endogenous proteins underpinning neurotransmission. We found frequent non-synaptic neurotransmitter vesicle fusion along the length of specific axons, whose presence is regulated by, and in turn regulates, the process of myelination. Our ongoing work seeks to identify the molecular mechanisms enabling this ‘axonal neurotransmission’ and neurotransmitter-induced signalling in myelinating oligodendrocytes. Our studies indicate that a non-synaptic glutamate transfer route is a key pathway mediating activity-regulated myelination, highlighting the need to consider both synaptic and non-synaptic modes of neurotransmission during the formation and function of the nervous system.