Knowledge of age sensitivity, the capacity of a behavioral test to reliably detect age-related changes, has utility in the design of experiments to elucidate processes of normal aging. We review the application of these tests in studies of normal aging and compare and contrast the age sensitivity of the Barnes maze, eyeblink classical conditioning, fear conditioning, Morris water maze, and rotorod. These tests have all been implemented to assess normal age-related changes in learning and memory in rodents, which generalize in many cases to age-related changes in learning and memory in all mammals, including humans. Behavioral assessments are a valuable means to measure functional outcomes of neuroscientific studies of aging. Highlighted in this review are the attributes and limitations of these measures in mice in the context of age sensitivity and processes of brain aging. Attributes of these tests include reliability and validity as assessments of learning and memory, well-defined neural substrates, and sensitivity to neural and pharmacological manipulations and disruptions. These tests engage the hippocampus and/or the cerebellum, two structures centrally involved in learning and memory that undergo functional and anatomical changes in normal aging. A test that is less well represented in studies of normal aging, the context pre-exposure facilitation effect (CPFE) in fear conditioning, is described as a method to increase sensitivity of contextual fear conditioning to changes in the hippocampus. Recommendations for increasing the age sensitivity of all measures of normal aging in mice are included, as well as a discussion of the potential of the under-studied CPFE to advance understanding of subtle hippocampus-mediated phenomena.
Age Sensitivity of Behavioral Tests and Brain Substrates of Normal Aging in Mice
John A. Kennard,D. Woodruff-Pak
Published 2011 in Front. Ag. Neurosci.
ABSTRACT
PUBLICATION RECORD
- Publication year
2011
- Venue
Front. Ag. Neurosci.
- Publication date
2011-04-24
- Fields of study
Biology, Medicine, Psychology
- Identifiers
- External record
- Source metadata
Semantic Scholar, PubMed
CITATION MAP
EXTRACTION MAP
CLAIMS
CONCEPTS
- age sensitivity
The capacity of a behavioral test to reliably detect age-related changes.
Aliases: age-sensitivity
- barnes maze
A rodent spatial navigation maze used to assess learning and memory.
- cerebellum
A brain structure involved in learning and motor control that is emphasized here as a substrate affected in aging.
- context pre-exposure facilitation effect
A contextual fear-conditioning variant in which prior context exposure facilitates later conditioning.
Aliases: CPFE
- eyeblink classical conditioning
An associative learning paradigm in which an eyeblink response is conditioned to a neutral stimulus.
Aliases: eyeblink conditioning, classical eyeblink conditioning
- fear conditioning
An associative learning task used to measure learned fear responses to cues or contexts.
Aliases: contextual fear conditioning
- hippocampus
A brain structure central to learning and memory that is emphasized here as a substrate affected in aging.
- morris water maze
A water-based spatial learning task used in rodents to assess navigation and memory.
Aliases: water maze
- rotorod
A rotating-rod test used to assess motor coordination and balance.
Aliases: rotarod, rotorod test