Early malnutrition, but not age, modulates in the rat the L-Arginine facilitating effect on cortical spreading depression.

Nutritional factors acting during brain development can permanently alter brain electrophysiology. L-Arginine is the precursor of nitric oxide synthesis, which can modulate brain function. Here we investigated the effect of early-in-life administration (during postnatal days 7-28) of L-Arginine (300 mg/(kg day)) on cortical spreading depression (CSD), recorded in well-nourished and malnourished (large litters technique) rats aged 30-40 days (young) and 90-110 days (adult). Compared to water-treated controls, well-nourished L-Arginine-treated rats, but not the malnourished ones, displayed higher CSD velocities (P<0.05) at both ages. The mean+/-S.D. CSD velocities (in mm/min) were: for water- and L-Arginine well-nourished rats, 3.78+/-0.23 and 4.36+/-0.19 (young groups), and 3.28+/-0.16 and 4.09+/-0.30 (adult); for the same conditions in the malnourished rats, 4.22+/-0.09 and 4.27+/-0.21 (young), and 4.11+/-0.18 and 4.21+/-0.33 (adult). L-Arginine treatment did not affect body and brain weights. It is concluded that early L-Arginine treatment long lastingly increased brain CSD-susceptibility and this effect is abolished by early malnutrition.