Effects of undernutrition during suckling on phosphoryl-serine levels in brain nuclear proteins of adult rats.

The effect of undernutrition during suckling on neurochemical and behavioral parameters were investigated in adult rats. Young rats were undernourished by suckling their lactating mothers fed an 8% (by wt) protein diet. Mothers of normal rats were fed a 20% protein diet. After weaning (d 21), normal and undernourished rats were fed a 20% protein diet until 90-120 d of age, when the rats were subjected to a short shuttle avoidance session and/or killed for neurochemical analyses. During shuttle avoidance sessions, footshock escape and footshock avoidance responses were analyzed simultaneously using 0.2- or 0.8-mA footshock intensity. In addition, the effect of undernutrition during suckling on phosphoryl-serine (P-Ser) level in brain nuclear proteins and the response of this level to a shuttle avoidance session were studied. We observed that undernutrition during suckling had no effect on footshock avoidance responses and decreased the latencies of footshock escape responses using 0.2-mA footshock intensity. Undernutrition decreased the basal level of P-Ser in brain nuclear proteins and abolished the decrease of this level observed in a shuttle avoidance session in normal rats using 0.2- or 0.8-mA footshock intensity.