Date: Friday, September 18,  2026
Time: 12:00pm – 1:00pm
Location: Simons Center Conference room 46-6011. Zoom: https://mit.zoom.us/j/94794483445

Speaker: Rani Borbara,  Ph.D.
Affiliation: Simons Postdoctoral Fellow, Steven Flavell Laboratory, Picower Institute for Learning and Memory, MIT

Talk title: The Connectome in Use: From anatomical wiring to functional organization in the behaving C. elegans brain

Abstract: A connectome is a map of possible interactions , not a record of how those possibilities are used by a behaving nervous system. Synaptic efficacy, electrical coupling, neuromodulation, and internal state continually reshape which anatomical pathways contribute to ongoing activity. The same wiring diagram can therefore support different dynamical regimes, while similar population dynamics can arise through different circuit routes. The central challenge is to understand how anatomical connectivity is expressed as functional organization.

C. elegans makes it possible to examine this problem across an entire nervous system at cellular resolution. Its neurons can be identified across animals, multiple layers of its connectome have been mapped, and brain-wide activity can be recorded during natural behavior. Using recordings from more than 150 freely moving animals, we train cross-animal models to predict each neuron’s activity from the rest of the population and derive cell-class-resolved maps of conditional functional dependence. We use these maps to ask which relationships generalize across individuals, how shared low-dimensional brain states contribute to apparent interactions, and where the remaining structure aligns with chemical synapses, gap junctions, and peptidergic signaling. These maps provide a quantitative description of the functional organization reproducibly expressed in whole-brain activity—and of the selective and imperfect imprint of anatomy upon it.

This work establishes a baseline against which perturbations can be read: activation and silencing of identified neurons, manipulation of neuromodulatory systems, and mutations in conserved autism-associated synaptic genes can each be used to test how defined changes to circuit components reorganize brain-wide functional dependencies and behavior.