Behavioral estimates of absolute visual threshold in mice.

Behavioral measurements on the water maze show night blindness in albino mice but cortical recordings show no difference between pigmented and congenic albino mice. Consequently we have measured the absolute threshold in albino and pigmented mice using an operant method. The estimated threshold value is -5.3 log cd/m2 for albino mice and -5.5 log cd/m2 for the pigmented mice. We conclude that threshold values depend on the behavioral paradigm used. Operant behavioral thresholds show that albino and pigmented mice detect levels of light similar to their VEP thresholds. Cognitive differences might influence the estimation of absolute behavioral threshold in albino animals.