Age-related changes in behavioural and neural variability in a decision-making task.

Area of Science:

• Neuroscience
• Aging Research
• Cognitive Decline

Background:

• Age-related cognitive decline, particularly in learning and decision-making, is often linked to heightened neural response variability.
• Understanding the neural underpinnings of these cognitive changes is crucial for developing interventions.

Purpose of the Study:

• To investigate the effects of aging on behavioral and neural variability using large-scale recordings in mice.
• To identify specific brain regions affected by age-related changes in neural activity and variability.

Main Methods:

• Recorded neural activity from over 18,000 neurons across 16 brain regions in younger and older mice.
• Mice performed a visual decision-making task to assess behavioral variability.
• Analyzed firing rates, neural variability (Fano factor), and variability quenching.

Main Results:

• Older mice displayed increased response time variability and globally elevated firing rates and neural variability.
• A decrease in variability quenching (reduced neural variability upon stimulus presentation) was observed in older animals.
• Specific regions like visual/motor cortex, striatum, and hippocampus showed higher firing rates, while thalamus showed lower rates. Variability quenching was attenuated in cortex, striatum, and thalamus.

Conclusions:

• Aging globally increases neural firing rates and variability while impairing stimulus-induced variability quenching.
• Age-related neural changes exhibit regional specificity, with distinct patterns in different brain areas.
• Large-scale neural recordings provide insights into the neural basis of age-related cognitive decline.