Completed Psychology & Behaviour Brain & Nervous System

Circuit principles of memory-based behavioral choice

Funder Wellcome Charity-funded
Recipient organisation University of Cambridge
Funding £1.7M
Period Jan 2019 — Jan 2024

In plain English

AI plain-English summary

Every time a fruit fly larva decides whether to approach or avoid a smell based on past experience, its brain is performing a series of computations that scientists have never been able to watch at the level of individual synapses—until now. The problem is that no one has had a complete, synapse-resolution wiring diagram of any brain system that handles memory-guided decision-making. Without that map, researchers cannot see which structural motifs in the neural circuit actually perform the three core computations: updating the value of a cue when expectations are violated, weighing conflicting cues to assign a value to each possible action, and then picking one action while suppressing others. This project uses a recently completed wiring diagram of the insect mushroom body—a brain region analogous to vertebrate cerebellar-like systems—in *Drosophila* larvae. By combining that map with a genetic toolkit that allows precise manipulation of individual neuron types, the researchers can now causally test which circuit motifs perform which computation. This is fundamental science. It will not directly improve infrastructure or diagnostics. But understanding how even a simple brain solves the problem of choosing between competing actions could, in the long term, inspire new architectures for artificial intelligence systems that must make decisions under uncertainty.

View original technical description
We aim to elucidate the circuit mechanisms underlying three key computations essential for memory-based behavioral choice: 1) updating valences attached to sensory cues, when actual and expected outcomes differ; 2) computing the “value” for each action, based on multiple, conflicting cues; and 3) selecting one action and suppressing other physically incompatible competing actions. One obstacle to progress in this field has been the problem of identifying underlying circuits with synaptic resolution, and causally relating structural motifs to their proposed function. Both insects and vertebrates have evolved cerebellar-like higher-order parallel-fiber systems specialized in forming large numbers of associative memories and in guiding memory-behavioral choice. However, no synapse-resolution wiring diagram of any such system has been available to guide analysis and inspire understanding. We have recently mapped the synaptic-resolution wiring diagram of one such system, the insect mushroom body, in Drosophila larva, which reveals multiple novel circuit motifs and provides clues about learning and decision-making models and their neuronal implementation. An exquisite genetic toolkit available in this model system allows selective manipulation of individual neuron types to establish causal relationships between their activity and behavior. We are now in a unique position to causally relate the identified structural motifs to their function.

View the original record at the funder ↗

Researchers

Marta Zlatic (EPMC Awardee)

Related Research

Grants with similar aims, by meaning.

Circuit mechanisms for behavioral choice from complete CNS activity and connectivity maps
Cooperative and competitive parallel memory units for choice behaviors
Functional connectomics of a simple brain centre for discrimination and memory
Decision Making and Learning in Neuronal Networks
Circuit Mechanisms of Learning and Decision Making

Original classification

Investigator Award in Science

Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.