About the Project
A memory of an experience is carried by a pattern of electrical activity across thousands of neurons. This project asks what the crucial elements of this 'neural code' are, and how the networks involved generate it.
A foundational element of this activity resides in the hippocampus. Hippocampal neurons fire in specific activity fields as an animal explores and learns. Hippocampal neural codes are among the best-described patterns in neuroscience. However most previous work is correlational or somewhat confounded. We aim to provide direct evidence for the importance of particular elements of the code. It remains unknown which features of population-level activity enable successful memory. Is it simply which neurons are active, and how strongly? Or does successful memory rely on the order in which they fire, and the millisecond timing between them? Equally unresolved is how the circuits build and use such activity patterns. What causes a distributed group of neurons to bind into a stable ensemble, which activity drives the synaptic changes that store it, and how does the network reconstruct a memory from a fragment, or hold similar experiences as distinct memories.
Until recently these questions were impossible to address directly, physiologically realistic activity could only be recorded and correlated to cognition or disrupted. It can now be written back into the brain of behaving animals. In an 'all-optical' experiment, thousands of individual neurons are recorded, the pattern present is analysed to identify neurons of interest, and then an experimenter-defined variant of the code is written back into those same neurons using millisecond-precision, cellular-resolution beams of light. All of this is done while the animal performs a memory task, inserting each experimental pattern and measuring the consequences for behaviour. In this case on learning and memory. In addition we will use electrophysiology to record neurons receiving the inserted activity, providing further insight into which features matter for broadcasting a memory around the brain.
Such experiments are enabled via a rare combination of approaches: two-photon population imaging, holographically targeted optogenetics, virtual reality behaviour, high-density Neuropixels recording and closed-loop control responsive to ongoing activity. In the Neural Coding for Memory Lab you would be trained in these methods as well as developing analytical and computational expertise, writing analysis code and translating measurements into network models.
This is an exceptional opportunity to pursue causal systems neuroscience at the resolution these questions demand and tackle fundamental questions on the neurobiology of memory.
Matthew Nolan is Professor of Neural Circuits and Computation at The University of Edinburgh. He is an expert on the memory systems and networks that the project will involve and has a large amount of experience mentoring and supervising students of all levels and postdocs. Matt is experienced with many of the techniques and challenges such experimental work involves and also has published modelling work centered around the function of the relevant neural networks.
This 4 year PhD project is part of a competition funded by EASTBIO BBSRC Doctoral Training Partnership (DTP). Detailed guidance on the application process, and the EASTBIO Application and Reference Forms can be found at How to Apply | Biology.
Please send your completed EASTBIO Application Form along with a copy of your academic transcripts (as a pdf) to INCR.PostgraduateRecruitment@ed.ac.uk. You should also contact your referees and ask them to submit their references (on the EASTBIO reference form template) to INCR.PostgraduateRecruitment@ed.ac.uk by the application deadline of 16th November 2026.
Funding Notes
This opportunity is open to UK and international students and provides funding covering stipend and UK level tuition fees. The University of Edinburgh covers the difference between home and international fees meaning that the EASTBIO DTP offers fully-funded studentships to all appointees. There is a cap on the number of international students the DTP recruits. It is therefore important for us to know from the outset which fees status category applicants will fall under when applying to our University.
Please refer to UKRI website and Annex B of the UKRI Training Grant Terms and Conditions for full eligibility criteria.