Calcium requirement and calcium therapy.

The mean calcium requirement of normal adults has been estimated from 212 calcium balances on 84 normal subjects and found to be 578 mg. The calcium allowance required to ensure that 95% of normal adults are in calcium balance is about 900 mg. Calcium requirement is relatively higher than that of phosphorus or magnesium because plasma calcium--and therefore urine calcium--is maintained at the expense of the skeleton in the presence of calcium deficiency, whereas plasma phosphate and magnesium--and therefore urine phosphate and magnesium--fall on phosphorus and magnesium deficient diets.

Effects of dorsomedial thalamic lesions on spatial discrimination reversal in the rat.

Eight rats with lesions of the dorsomedial thalamus and 10 rats with sham operations were compared on acquisition and subsequent reversals of a spatial discrimination. The rats with thalamic damage showed greater perseveration to the incorrect choices (p less than 0.002) and made fewer reversals (p less than 0.