Lenzi, Stephen;
(2021)
A Role for the Tail of the Striatum in the Adaptive Control of Innate Escape Behaviour.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
Laboratory mice show robust escape responses to overhead, high-contrast visual looming stimuli. However, it is sometimes evolutionarily advantageous to suppress instinctive behaviours such as escape, for example when through experience, a specific stimulus is realised to be non-threatening. Dopaminergic neurons in the Substantia Nigra pars Lateralis (SNL) which project to the Tail of the Striatum (TS) are part of a candidate pathway for mediating such adaptative behaviours since they are thought to signal threat prediction error. Also, the SNL and the TS are densely interconnected with several key structures that mediate escape behaviour and our preliminary lesion experiments show that they are necessary for escape. Here I investigated whether the SNL-TS circuit could mediate the learned control of escape behaviour using a behavioural protocol that results in the learned suppression of innate escape (LSIE) to visual stimuli that were previously threatening. LSIE lasted for over two weeks and did not reduce the probability of escape to threatening auditory stimuli. Photometry experiments in the TS showed reliable, large calcium signals in dopaminergic inputs in response to looming stimuli that correlated with threat level and escape probability. Such TS dopamine signals were reduced during and following LSIE. Similarly, both D1- and A2a-receptor-expressing neurons in the TS showed reduced responses following LSIE indicating that these dopaminergic responses to looming stimuli undergo experience-dependent modulation. Dopaminergic TS signals could therefore be involved in the modulation of escape behaviour that may be adjusted according to prior experience and threat prediction.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | A Role for the Tail of the Striatum in the Adaptive Control of Innate Escape Behaviour |
| Event: | UCL (University College London) |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2021. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > The Sainsbury Wellcome Centre |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10133992 |
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