Investigating the role of D2 receptors in cognition
Research type
Research Study
Full title
Investigating the role of D2 receptors in cognition
IRAS ID
166718
Contact name
Oliver Howes
Contact email
Duration of Study in the UK
5 years, 0 months, 1 days
Research summary
This study sets out to investigate the role of a neurotransmitter called dopamine in cognition in humans. We are interested in the actions of one dopamine receptor in particular, the D2 receptor (D2R). All antipsychotic drugs block this receptor, and so it is thought that hyperactivity of these receptors is a cause of psychosis (e.g. in schizophrenia or in bipolar disorder). Schizophrenia is a very debilitating disorder in which those afflicted – 1% of the population – suffer from hallucinations and delusions (unusual beliefs held with great tenacity), and other cognitive problems.
How the above symptoms relate to the D2R is not clear, mainly because the contribution of D2Rs to cognition is little understood. Recent studies using drugs which activate D2Rs have shown that increased activity at D2Rs makes it harder for a subject to change their current preferred response to a different response, following a change in feedback (called reversal learning) e.g. den Ouden et al (2013, Neuron). We have investigated this effect using a computational model of a well-known psychological paradigm, the 'beads task', in healthy subjects who score high or low on questionnaire measures of schizotypy (psychotic-like symptoms). We found that subjects with higher schizotypy scores found it harder to change their responses. We also showed that this effect correlated with a single (behavioural flexibility) parameter in our computational model of the task (unpublished data).
We would therefore like to see whether differences in this computational parameter correlate with differences in their D2R availability, in healthy subjects with high and low psychotic-like symptoms, in different tasks. If so, this would indicate a specific computational role for the D2R in cognition, and it could also explain why delusional beliefs become so fixed and hard to change in psychosis.
REC name
London - Queen Square Research Ethics Committee
REC reference
15/LO/0011
Date of REC Opinion
4 Feb 2015
REC opinion
Further Information Favourable Opinion