Neonatal administration of goat whey modulates memory and cortical spreading depression in rats previously suckled under different litter sizes: Possible role of sialic acid.

Objectives: Goat whey, a usually discarded byproduct from goat cheese manufacturing, is a good source of sialic acid (SA), an oligosaccharide that is involved in processes such as memory and brain excitability. Here, we investigated in rats the effect of dried goat whey (DGW) on memory and the brain excitability-dependent phenomenon known as cortical spreading depression (CSD). We also provide evidence for the involvement of SA in this effect. In addition, we tested animals under unfavorable suckling conditions to evaluate whether nutritional deficiency would modulate DGW action.

Methods: Wistar rats were suckled in litters with 9 and 15 pups (groups L and L, respectively). From postnatal (P) days 7-14, the animals received per gavage 17.45 g of DGW/kg/day, or SA (20 mg/kg/day or 100 mg/kg/day). At P28-30, we tested the animals' memory in the object recognition paradigm. At P35-45 we recorded CSD and analyze its velocity of propagation, amplitude, and duration.

Results: In the object recognition test, the L DGW-treated rats performed better than the L-controls. The L rats displayed higher CSD velocities compared with L groups. The DGW and SA groups exhibited higher CSD velocity than the naïve- and saline-treated controls, regardless the lactation status (P < 0.05).

Discussion: Our results documented a novel effect of DGW on memory and CSD. SA dose-dependently facilitated CSD, suggesting its involvement on the DGW action. DGW is considered a potential supplement to improve brain development and function in malnourished children, and this shall be further translationally investigated.