Perirhinal neuronal activity and recognition memory mechanisms

Lead Research Organisation: University of Bristol
Department Name: Anatomy


Recognition memory, being able to judge that something has happened or been encountered previously, is essential to normal everyday life, including both employment and leisure pursuits. When the judgement of prior occurrence is impaired, as for example in the many sufferers from Alzheimer's disease, questions, statements and tasks are inappropriately repeated. Previous work has established that it is possible to study the processes underlying recognition memory in rats, and that these processes involve a specific brain region in the temporal lobe, the perirhinal cortex. The proposed work will determine how neuronal activity in this brain region signals information of importance to recognition memory and how such signalling is changed by highly selective drugs that are known to impair recognition memory. The drugs to be used will block specific types of glutamate receptors: glutamate receptors are essential to the way most neurons communicate with other neurons. Moreover, glutamate receptors are implicated in synaptic plastic processes that change how neurons interconnect and so potentially underlie memory. Their study is therefore critical to understanding how information necessary to recognition memory is processed and stored. The key goals are to determine what is being signalled by different types of perirhinal neurons and hence the different contributions of different types of such neurons to recognition memory, how these signals are changed in different ways by blocking different types of glutamate receptors, and to investigate the relationship of such signal changes to what is known of synaptic plastic processes. The information obtained will advance understanding of the neural basis of recognition memory.

Technical Summary

To elucidate the neuronal substrates of recognition memory, multiple single neuronal recordings will be made from rats presented with novel and familiar visual stimuli. Recordings will be made from the perirhinal cortex, which is crucial to the familiarity discrimination component of recognition memory. Long-term recordings will be made to determine the properties of different types of perirhinal neurons in relation to recognition memory. Changes in the activity of neurons signalling information related to the prior occurrence of stimuli will be related to the local delivery of selective glutamate receptor antagonists that produce different patterns of recognition memory loss. The key goals are: (i) to provide a description of neuronal activity underlying familiarity discrimination; (ii) to determine how such activity is changed by selective antagonists of specific types of glutamate receptor (NMDA and kainate); (iii) thereby to provide an explanation for the different recognition memory impairments produced by kainate and NMDA glutamate receptor antagonists through their actions on neurons with specific response patterns; (iv) to relate different types of neuronal response changes to the known actions of the antagonists on perirhinal plasticity mechanisms; and (v) thereby to increase understanding of the neural basis of recognition memory.


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Bolhuis JJ (2015) Brain, memory and development: the imprint of Gabriel Horn. in Neuroscience and biobehavioral reviews

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Brown MW (2015) In search of a recognition memory engram. in Neuroscience and biobehavioral reviews

Description Neuronal responses were recorded in the perirhinal cortex of rats while viewing novel and familiar pictures. Examples of responses were found to visual and auditory/reward stimuli, including responses that changed on stimulus repetition. These latter evidenced information of potential use to recognition memory. Some neurons' responses could be tracked across days. An unexpected result was that responses were only identified when "D visual stimuli were projected and not during spontaneus explorat
Exploitation Route A research publication of these results is being drafted.
Sectors Other

Description Information in publications used by other scientific researchers.
Sector Pharmaceuticals and Medical Biotechnology
Description RUM 
Organisation Stony Brook University
Country United States 
Sector Academic/University 
PI Contribution Expertise
Collaborator Contribution Equipment and software and expertise
Impact Potential research publications. Neuroscience
Start Year 2006
Description Brain Awareness Week 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Type Of Presentation Keynote/Invited Speaker
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Public interest engaged

Year(s) Of Engagement Activity 2008,2009,2010
Description Talks 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Type Of Presentation Keynote/Invited Speaker
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Talks in UK, Austria, Russia, USA. Audiences from 50 to several 100. Duration 20 min - 1 hour. Feedback always positive.

Further invitations
Year(s) Of Engagement Activity 2006,2007,2008,2009,2010
Description Women in Science and Engineering 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Type Of Presentation Paper Presentation
Geographic Reach Regional
Primary Audience Schools
Results and Impact 6th Form students learned more about career opportunities.

Not recorded.
Year(s) Of Engagement Activity 2010