Neuronal communication is essential for proper functioning of the brain. Fast communication between neurons occurs through specialized contact sites, called synapses. At synapses, chemical signals in the form of neurotransmitters are released at the presynaptic site to be recognized by postsynaptic receptors that directly oppose the release site. A large variety of specific molecular complexes is enriched at neuronal synapses to control the clustering of receptors. The dynamic and efficient clustering of neurotransmitter receptors at synapses is critical for efficient synaptic transmission. Importantly, synaptic structure and function are highly plastic: changing the molecular composition and organization of synapses is thought to support the ability of the brain to learn and memorize. Indeed, disruptions in the structure and function of synapses are broadly held to underlie the development of neurological disorders such as autism and schizophrenia. Over the past decades, intense research efforts have identified and characterized synaptic components, i.e. we have a detailed “parts list” of the synapse. However, despite these efforts, we lack understanding of how these individual molecular components are assembled into functional synapses.
The overall objective of this project is aimed at understanding the molecular mechanisms that establish and modulate the molecular architecture at neuronal synapses and thereby shape the efficiency of synaptic signal transmission. Specifically, this project aims to reveal the nanoscale molecular organization at excitatory synapses that controls neurotransmitter receptor positioning, and to test how this organization contributes to neuronal functioning.
Progress in this direction has been largely hampered by experimental limitations to label and visualize molecular components within individual synapses. Therefore, in this project, we developed novel labeling and microscopy techniques to reveal the nanoscale organization of neurotransmitter receptors at neuronal synapses. Using these approaches we revealed important biological mechanisms that contribute to the molecular organization of neuronal synapses. Moreover, we tested the contribution of these mechanisms to synaptic function using physiological measures of synaptic transmission and plasticity.
Altogether, this project will reveal mechanistic insights in how the distribution of neurotransmitter receptors shapes synaptic transmission and plasticity. Given that synaptic dysfunction, and in particular disruption of receptor signaling, has been implicated in neurological disorders such as autism and schizophrenia, this project will provide highly relevant new insights in the mechanisms that underlie these diseases.
