Altered pyramidal cell dendritic development in the motor cortex of lead intoxicated neonatal rats. A Golgi study.
Neonatal Long-Evans rat pups were given the standard dose, 600 mg of lead acetate per kg of body weight every 24 hours beginning one day after birth until a cumulative dose of 2400 mg/kg (4 doses) had been administered via stomach intubation. Blood lead levels in lead treated rats averaged 526.35 micrograms/dl at 10 days of age. Blood lead values in age-matched controls averaged 0.079 microgram/dl. The body weights of the lead treated rats were not significantly different than control rats at 30 days of age. The brain weights were significantly greater than those of control rats at 30 days. Camera lucida drawings of pyramidal cells from motor cortex of control rats contained significantly (54%) more secondary and tertiary branches extending laterally from the primary apical dendrite than pyramidal cells of lead treated rats. The dendritic branches were numbered according to their branching point away from the soma. There was a significant reduction in the number of 4, 5, 6, and 7th order branches extending from the apical dendrite and 3 and 4th order branches extending from the basal dendrites in the leaded-rats. The mean dendritic length was reduced by 19% in basal dendrites and by 28% in apical dendrites. Measurements of dendritic material by the Scholl method revealed 17% reduction in the basal dendrites and a 36% reduction in the apical dendritic material in treated rats. These results suggest that neonatal lead exposure alters the dendritic development of pyramidal cells of rat motor cortex.
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D
Lorton
W J
WJ
Anderson
D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight; D001921:Brain / Q000473:pathology; D003712:Dendrites / Q000473:pathology; D007855:Lead Poisoning / Q000473:pathology*; D008297:Male; D009044:Motor Cortex / Q000473:pathology*; D009046:Motor Neurons / Q000473:pathology*; D009929:Organ Size; D051381:Rats