Fischer 344 rats display age-related memory deficits in trace fear conditioning.
A functional hippocampus is required for trace fear conditioning, which involves learning the association of a tone and shock that are separated over time. Young and aged rats received 10 trace conditioning trials. Twenty-four hours later, rats were tested for fear to the tone in a novel chamber by measuring freezing. The results showed significantly lower levels of freezing in aged rats as compared with young rats, which provides evidence of age-related memory impairments. Pseudorandom conditioning groups showed low levels of freezing, indicative of no associative memory. Age-related memory deficits were not found with delay conditioning, which suggests no age-related sensory-motor deficits. These data suggest that aging hinders the ability of the hippocampus to process information separated over time.
Villarreal
Julissa S
JS
Department of Biology, University of Texas at San Antonio, San Antonio, TX 78249, USA. jsvillareal@utsa.edu
Dykes
James R
JR
Barea-Rodriguez
Edwin J
EJ
D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D003213:Conditioning, Psychological / Q000502:physiology*; D005239:Fear; D007103:Immobilization / Q000502:physiology; D008297:Male; D008569:Memory Disorders / Q000503:physiopathology*; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors