Eyeblink conditioning deficits in the old cat.
Acquisition of a conditioned eyeblink reflex was studied in aged cats 10-23 years old and young cats one to three years old. All ten young cats became conditioned within 1,000 trials, after a mean of 270 trials, with a stimulus protocol including a 1500 msec 4 kHz tone CS+ followed by a shock unconditioned stimulus, and click CS-. Nine of 15 aged cats failed to become conditioned with 1,000 trials. Six old cats became conditioned after a mean of 522 trials. Four aged cats tested with a simpler protocol involving a 400 msec CS+ and no click CS- became conditioned with less than 500 trials. All retained the conditioned response when clicks were added to the 400 msec CS+. Three aged animals which failed to become conditioned with the 1500 msec CS+ and clicks were trained with an 800 msec CS+ without clicks. Only one became conditioned within 500 trials. Thus duration of the tone CS+ was critically important for acquisition of a conditioned eyeblink response by aged cats.
D000375:Aging; D000818:Animals; D001767:Blinking; D002415:Cats; D003214:Conditioning, Classical / Q000502:physiology*; D004576:Electromyography; D012018:Reflex / Q000502:physiology