Completed Brain & Nervous System Psychology & Behaviour

Decoding neural assemblies over multiple brain regions, extended experience and sleep-wake cycles

Funder Wellcome Charity-funded
Recipient organisation University of Bristol
Funding £1.3M
Period Oct 2016 — Sept 2021

In plain English

AI plain-English summary

A rat’s brain is being recorded continuously for over 24 hours to track how groups of neurons form, change, and interact across multiple regions during waking behaviour and sleep. This work addresses a fundamental gap in neuroscience: the concept of “cell assemblies”—groups of neurons that fire together in behaviour-dependent patterns—has existed since 1949, but no one has directly observed how these assemblies are wired, how long they persist, how they update with new information, or how they interact across brain regions. The researcher will use long-term electrophysiology and optogenetics to map and silence specific neurons in six functionally related brain areas, including the hippocampus, amygdala, and cortex. This is fundamental science with no immediate practical application. If successful, it would provide the first biological description of how neural assemblies form stable information-processing networks across heterogeneous experiences and sleep states. Understanding how REM and non-REM sleep contribute to cognition could eventually inform treatments for memory or learning disorders, but the primary aim is to resolve a long-standing mystery about the brain’s basic operating principles.

View original technical description
Neural populations co-activated in behaviour-dependent patterns are conceptualised as “cell assemblies” and “phase sequences” (Hebb, 1949). However, the biology of assemblies remains enigmatic: how are assemblies wired, both individually and into constellations of functionally related modules? How long do they last? How are they updated to incorporate new information? I aim to tackle these issues, which form the foundations of neural information processing and cognitive dysfunction. Using long-term, in vivo electrophysiology and unbiased statistics to identify and track distributed assemblies over >24h timescales in rat brain, I will define: 1. The properties and interactions of assemblies embedded in diverse, functionally-related brain regions (hippocampal CA3 and CA1, basolateral amygdala, nucleus accumbens, prelimbic and parietal cortex), using optogenetic stimulation to map and silence the connectivity of constituent neurons. 2. How assemblies established in one cognitive context are updated in different contexts involving overlapping psychological constructs. 3. The cognitive contributions of structured assembly activity during REM and non-REM sleep. This work will establish how assembly formation relates to neural connectivity, how assemblies interact across brain regions, how assembly dynamics enable stable information processing during heterogeneous behavioural experiences and how REM and non-REM sleep – universal biological states of ill-defined function – contribute to cognition.

View the original record at the funder ↗

Researchers

Matt Jones (EPMC Awardee)

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Original classification

Senior Research Fellowship Basic

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