Evolutionary origin of synapses and neurons - Bridging the gap

Area of Science:

• Evolutionary biology
• Neuroscience
• Cellular signaling

Background:

• The evolutionary origin of synapses and neurons remains a complex and debated topic.
• Non-bilaterian metazoans and their relatives possess molecular components crucial for synapse function.
• Existing research often overlooks the broader phylogenetic context beyond metazoans.

Purpose of the Study:

• To investigate the evolutionary origins of synapses and neurons.
• To understand the assembly of molecular toolkits into ancient synaptic signaling machineries.
• To bridge the gap in understanding by adopting an integrative phylogenetic approach.

Main Methods:

• Comparative analysis of molecular components across diverse phyla.
• Phylogenetic reconstruction including unicellular relatives of metazoans (ichthyosporeans, filastereans, choanoflagellates).
• Integration of genomic and functional data to infer ancestral states.

Main Results:

• Identification of conserved molecular building blocks for synaptic function predating neurons.
• Reconstruction of the stepwise evolution of pre- and postsynaptic signaling pathways.
• Evidence for the early assembly of synaptic machinery in unicellular and early metazoan ancestors.

Conclusions:

• Understanding synapse and neuron evolution requires an integrative approach including unicellular relatives.
• Early evolution involved the assembly of pre-existing molecular components into novel signaling systems.
• This framework provides insights into the timing and mechanisms of early synaptic evolution.