Description:

Title: "A serotonergic axon-cilium synapse"

Abstract:

Chemical synapses between axons and dendrites mediate neuronal intercellular communication. Using enhanced focused ion beam-scanning electron microscopy on samples with optimally preserved ultrastructure, we discovered synapses between axons and the primary cilia of target neurons. Mediated by serotonin released from axonal varicosities and the cilia-restricted serotonin receptor 5-hydroxytryptamine receptor 6 (gene: HTR6, protein: 5-HT6), activation of axo-ciliary synapses drives a RhoA-mediated signaling cascade that modifies nuclear actin to acetylate histones and increase chromatin accessibility. As a signaling apparatus with proximity to the nucleus, axo-ciliary synapses short circuit neurotransmission to alter the postsynaptic neuron’s epigenetic state.

Guest Speaker:

Shu-Hsien Sheu, MD, PhD; Team Leader, Chan Zuckerberg Institute.