Auditory startle response is diminished in rats after recovery from perinatal copper deficiency

Abstract

Recovery from perinatal copper deficiency was studied in female and male Sprague Dawley rats for 6 mo. Month-old offspring reared by dams on copper- deficient treatment starting d 7 of pregnancy had up to 80% reductions in regional brain copper concentrations compared with offspring from copper- supplemented dams. Liver copper concentrations and plasma ceruloplasmin diamine oxidase activities of copper-deficient rats were restored to control levels within 1 mo of nutritional repletion with dietary copper. However, brain copper concentrations, with the exception of the hypothalamus and medulla, remained lower than in controls even after 5 mo of treatment. Rats were screened for startle responses and foot splay after 1, 3 and 5 mo of repletion. Diminished auditory startle was evident in rats of both sexes at all repletion times tested, whereas tactile startle and preimpulse inhibition of tactile startle were not influenced by prior copper deficiency, suggesting auditory sensory perception abnormalities. In a separate study, postweanling male rats deprived of dietary copper for 5 wk exhibited clear signs of copper deficiency but normal acoustic startle responses and foot splay. Long-term neurochemical and behavioral abnormalities persist in rats after perinatal copper deficiency.