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.