ACQUISITION OF A CONDITIONED REFLEX IN NEW-ZEALAND WHITE-RABBITS FROM3 SOURCES

In studies of learning using rabbits, there has been standardization o f behavioural procedures across laboratories. Less attention has been paid to variation that may arise from genetic differences and/or diffe rences in rearing conditions. The present experiment revealed that acq uisition of a conditioned reflex can be affected dramatically by such differences. Specifically, the acquisition of a conditioned reflex in New Zealand White (NZW) rabbits from 3 different suppliers was compare d. All rabbits received behavioural training in which a tone or a ligh t signalled an electrotactile stimulation of the trigeminal nerve near the rabbits' right eye. This tactile stimulus reliably elicited an ey eblink. Repeated presentations of the auditory and visual signals foll owed by the tactile stimulus yielded the acquisition of a conditioned response (CR), namely closure of the eyelids during the warning period provided by the signal stimuli. Two of the groups showed steady CR ac quisition at a rate that matched previous results in other laboratorie s as well as in the senior author's laboratory. However, the third gro up of rabbits showed very slow acquisition, and some rabbits failed to show any CR acquisition.