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Brain wiring determinants uncovered by integrating connectomes and transcriptomes
- Yerbol Kumangalliyev
- how are connectomes encoded in genomes?
- we have access to all molecules present in all cells
- using the motion detection circuit T4/T5 neurons
- complete connectome available from Janelia
- transcriptomes of all T4 subtypes and LPC cells reveals they are developmentally sister cells
- most T4/T5 express similar adhesion molecules
- there are 2 parallel synaptic pathways revealed from ligand receptor pairs in these neurons
- they select the best match not the perfect match restricting synaptic target sites to specific layers but it may not be perfect ligand receptor matches
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The first complete connectome of an adult insect nerve cord (MANC)
- Elizabeth Marin (Greg Jefferis lab)
- the problem of how to define cell types
- they typed 23,000 in the nerve cord
- you can use morphology, neurotransmitters, or developmental lineage
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Seymore Benzer Lecture
- Marc Freeman
- the nervous system is pruned over time - called remodeling
- some cells also die and are eliminated from circuits
- what role do glia play in local pruning?
- do they actively select neurons or just recycle the dead neurons
- glia act as agents when we think about them in this way…
- using metamorphosis as the system because there is a huge amount of remodeling occurring from larva to pupa to fly and specifically looking at Crz neurons
- lots of crz neurons present in in larva but none in pupa
- Turtle protein drives caspase activation
- knockdown in Crz neurons and there is no cleaving of caspase and this activates degeneration — many of the neurons die but always the same 2 remain in one of the segments
- tweek is a highly conserved gene
- involved in phagocytosis and activates engulfment gene
- the protein is a huge tubular structure with a hydrophobic pore
- Bridge like Transfer protein (BLTP)
- pour lipids from ER to cytoplasm