Visual evoked response testing method for neonatal rats.
Visual evoked responses (VER's) were recorded from pentobarbital-sedated neonatal Fischer 344 rats at 10, 12, 14 and 22 days of age. Subcutaneously placed needle electrodes were used to record VER maturation within individual animals. The mean latency to the first negative peak was 190.8 msec at 10 days of age, 117.4 msec at 12 days of age, 84.2 msec at 14 days of age and 39.4 msec by 22 days of age. Larger pups had shorter latencies, and males had shorter latencies than females. When latencies were adjusted for body weight differences (females were lighter), there were no sex differences. There were significant latency differences between litters. Repeatability was demonstrated by the persistence of pup-to-pup order (fastest to slowest latency), from 12 to 14 days of age.
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001835:Body Weight; D005074:Evoked Potentials, Visual; D005260:Female; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D011930:Reaction Time / Q000502:physiology; D012737:Sex Factors; D014795:Visual Pathways / Q000502:physiology*