Location and temporal memory of objects declines in aged marmosets (Callithrix jacchus)

Area of Science:

• Neuroscience
• Primate Cognition
• Aging Research

Background:

• Episodic memory decline is a key indicator of cognitive aging in humans.
• Episodic-like memory models exist in animals, but few focus on aging.
• Marmosets are emerging models in aging science, but their episodic-like memory has not been studied, especially in aged individuals.

Purpose of the Study:

• To investigate episodic-like memory decline in aging marmosets.
• To assess the 'what-when' and 'what-where' components of memory in young and old marmosets.
• To establish a naturalistic approach for testing memory in marmosets.

Main Methods:

• A naturalistic approach using spontaneous object exploration in the home cage.
• A three-trial task with a one-week inter-trial interval.
• Quantification of exploratory behavior and calculation of discrimination indices in 20 marmosets (young and old).

Main Results:

• Young marmosets demonstrated preserved memory for combined 'what-where' and 'what-when' information.
• A significant decline in these memory components was observed in aged marmosets.
• Exploratory behavior analysis revealed age-related memory deficits.

Conclusions:

• Episodic-like memory, encompassing 'what-when' and 'what-where' information, declines with age in marmosets.
• Aged marmosets exhibit deficits in memory recall, supporting their use as a model for cognitive aging.
• These findings suggest potential for studying age-related memory impairments in this primate species.