Marieke Martens

The main focus of my role is providing supervision and support for everything neuroimaging related (brain MRI) within PERL and the wider Depression Therapeutics Theme (part of NIRH Oxford Health BRC).

Within the Psychopharmacology and Emotion Research Laboratory (PERL) we explore the ways in which the brain processes emotional information and how this is affected by chemical messengers in the brain (neurotransmitters) such as serotonin, noradrenaline and dopamine. As well as telling us about normal brain function, this may help us understand emotional disorders such as depression and how these may be helped by drug treatments that affect neurotransmitter function. We attempt to understand how conventional treatments may work, and also whether we can predict new candidate treatments for depression and anxiety using experimental medicine models. Key methods include cognitive neuroscience, functional brain imaging (fMRI) and biomarker approaches, using both patient groups and healthy volunteer studies.

In addition to my support role I also lead studies that aim to better understand a brain area important for emotional processing called the amygdala, using an MRI scanner that scans with great spatial detail (7 Tesla MRI scanner). Using the 7T scanner allows us to obtain an unprecedented level of detail of brain structure and function. My hope is that understanding more about antidepressants, and the chemical messenger serotonin, will eventually benefit treatment response prediction and drug development, to ultimately improve the lives of patients with depression.

I am also a tutor on the FSL course and organiser of FMRIB's Graduate Course for MRI analysis. 

During my DPhil, together with Prof. Paul Harrison and Prof. Elizabeth Tunbridge, I aimed to understand how genetic factors impact on brain functions relevant to psychiatric illness. We focused in particular on the catechol-O-methyltransferase’s (COMT) gene. COMT influences the function of dopamine, which is implicated in a number of psychiatric disorders, but is also critical in healthy brain functions.
Previous work in our lab showed that a drug that inhibits COMT increases dopamine levels in the brain and improves memory and attention. Moreover it was discovered that a person’s genetic make-up determines whether the drug will improve memory or not. These findings emphasise that genetic factors can influence the response to a drug and suggest that in the future successful therapies may need to take a person’s individual genetic make-up into account. The main objective of my DPhil was to extend these findings by investigating COMT’s impact on brain functions beyond memory (like emotional processing) but more importantly, how the links between dopamine, COMT and memory are altered by environmental factors like stress.