Disputation: Elise Holter Thompson

PhD candidate Elise Holter Thompson at the Department of Biosciences will be defending the thesis "Perineuronal nets in memory processing and behavior" for the degree of Philosophiae Doctor.

Profile picture of Elise Holter Thompson

Elise Holter Thompson

The disputation will be live streamed using Zoom. The host of the session will moderate the technicalities while the chair of the defence will moderate the disputation.

Ex auditorio questions: The chair of the defence will invite the audience to ask ex auditorio questions either written or oral. This can be requested by clicking "Participants" followed by clicking "Raise hand". 

The meeting opens for participation just before 12.15 PM, and closes for new participants approximately 15 minutes after the defense has begun.

Trial lecture 

"Exceptional memory, being able to forget and reverse learning"

Main research findings

How the brain balances between plasticity and stability to create and store memories remains elusive. While brain plasticity is massive in early life, it is reduced in adults. A specialized form of extracellular matrix, called perineuronal nets, enwraps neurons contributing to reduced plasticity. Removal of PNNs in adults reinstates high plasticity but their functional roles remain mostly unresolved.         

In her doctoral work, Elise Thompson has used advanced experimental approaches to reveal the impact of PNNs on neuronal activity, behavior and memory processing.         

To test the proposed role of PNNs to stabilise neural networks, Thompson and colleagues removed PNNs in adults after memory acquisition. Results showed that PNN removal led to amnesia, illustrating a role for PNNs in memory processing, perhaps by stabilising connections to other involved brain areas.

Furthermore, Thompson and colleagues investigated a mouse line with a genetic mutation disrupting PNN development. In a comprehensive evaluation, they found that these mice showed reduced levels of anxiety, with no other apparent changes to memory processing and neuronal activity.

The results from Elise Thompson’s work suggest that while acute loss of PNNs may have drastic consequences, such as amnesia, disrupting PNN development may allow unknown compensatory effects ensuring normal functionality.

Perineuronal net in green wrapped around a neuron in red
Perineuronal net in green wrapped around a neuron in red.

Copyright: Thompson et al. 2018. Removal of perineuronal nets disrupts recall of a remote fear memory. PNAS

Department of Biosciences

Published Nov. 27, 2020 11:09 AM - Last modified Feb. 4, 2022 3:57 PM