Building a brain one stem cell at a time  Add To Calendar

Speaker: Elizabeth S. Heckscher, University of Chicago
Host: Park
  • Date(s): Thursday, 2/16 4:00 PM to Thursday, 2/16 5:00 PM
  • Campus Address: 4289 SEL, 840 West Taylor St

Neuronal stem cell lineages are the fundamental developmental units of the brain, and neuronal circuits are the fundamental functional units of the brain. Determining lineage-circuitry relationships is essential for deciphering the developmental logic of circuit assembly. While the spatial distribution of lineage-related neurons has been investigated in a few brain regions, an important, but unaddressed problem is whether temporal information that diversifies neuronal progeny within a single lineage also impacts circuit assembly. Circuits in the sensorimotor system (e.g., spinal cord) are thought to be assembled sequentially, making this an ideal brain region for investigating the circuit level impact of temporal patterning within a lineage. Here we use intersectional genetics, optogenetics, high-throughput behavioral analysis, single neuron labeling, and connectomics to determine how a set of bona fide lineage-related interneurons contribute to sensorimotor circuitry in the Drosophila larva. We show that Even-skipped lateral interneurons (ELs) are sensory processing interneurons. Late-born ELs contribute to a proprioceptive body posture circuit, whereas early-born ELs contribute to a mechanosensitive escape circuit. These data support a model in which a single neuronal stem cell can produce a large number of interneurons with similar computational capacity that are distributed into different circuits based on birth timing. In summary, these data establish a link between temporal specification of neuronal identity and circuit assembly.

Ellie Heckscher_sm