Favorable and unfavorable lactation modulates the effects of electrical stimulation on brain excitability: a spreading depression study in adult rats.

AIMS: We investigated how different nutritional states resulting from distinct lactation conditions modulate the effects of cortical electrical stimulation (CES) on the excitability-related phenomenon known as cortical spreading depression (CSD). MAIN METHODS: Wistar rats were reared in different litter sizes with 12, 6 or 3 pups, designated as malnourished (M), well-nourished (W) and overnourished (Ov), respectively. CSD was recorded for 4h on 2 cortical points of each cerebral hemisphere at baseline and after CES. CES was applied for 20 min on the left cortex using a bipolar electrode placed between the CSD recording electrodes. Paired Student t test and ANOVA followed by Tukey test were used for statistical analysis (p<0.05). KEY FINDINGS: The lactation conditions significantly influenced body weight (the M and Ov groups presented the lowest and largest average weight, respectively) and modified the CSD velocities of propagation in adulthood (Ov