Perirhinal cortex and the recognition of relative familiarity

Ameen-Ali, Kamar E.; Sivakumaran, Magali H.; Eacott, Madeline J.; O'Connor, Akira R.; Ainge, James A.; Easton, Alexander

Abstract

Spontaneous object recognition (SOR) is a widely used task of recognition memory in rodents which relies on their propensity to explore novel (or relatively novel) objects. Network models typically define perirhinal cortex as a region required for recognition of previously seen objects largely based on findings that lesions or inactivations of this area produce SOR deficits. However, relatively little is understood about the relationship between the activity of cells in the perirhinal cortex that signal novelty and familiarity and the behavioural responses of animals in the SOR task. Previous studies have used objects that are either highly familiar or absolutely novel, but everyday memory is for objects that sit on a spectrum of familiarity which includes objects that have been seen only a few times, or objects that are similar to objects which have been previously experienced. We present two studies that explore cellular activity (through c-fos imaging) within perirhinal cortex of rats performing SOR where the familiarity of objects has been manipulated. Despite robust recognition memory performance, we show no significant changes in perirhinal activity related to the level of familiarity of the objects. Reasons for this lack of familiarity-related modulation in perirhinal cortex activity are discussed. The current findings support emerging evidence that perirhinal responses to novelty are complex and that task demands are critical to the involvement of perirhinal cortex in the control of object recognition memory.

Citation

Ameen-Ali, K. E., Sivakumaran, M. H., Eacott, M. J., O'Connor, A. R., Ainge, J. A., & Easton, A. (2021). Perirhinal cortex and the recognition of relative familiarity. Neurobiology of Learning and Memory, 182, Article 107439. https://doi.org/10.1016/j.nlm.2021.107439

• Journal Article Type: Article
• Acceptance Date: Apr 9, 2021
• Online Publication Date: Apr 14, 2021
• Publication Date: 2021-07
• Deposit Date: Apr 12, 2021
• Publicly Available Date: May 20, 2021
• Journal: Neurobiology of Learning and Memory
• Print ISSN: 1074-7427
• Electronic ISSN: 1095-9564
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 182
• Article Number: 107439
• DOI: https://doi.org/10.1016/j.nlm.2021.107439
• Public URL: https://durham-repository.worktribe.com/output/1249987