Abstract
Perinatal choline supplementation in rats is neuroprotective against insults such as fetal alcohol exposure, seizures, and advanced age. In the present study we explored whether dietary choline supplementation may also confer protection from psychological challenges, like stress, and act as a natural buffer against stress-linked psychological disorders, like depression. We previously found that choline supplementation increased adult hippocampal neurogenesis, a function compromised by stress, lowered in depression, and boosted by antidepressants; and increased levels of growth factors linked to depression, like brain-derived neurotrophic factor. Together, these were compelling reasons to study the role of choline in depressed mood. To do this, we treated rats with a choline supplemented diet (5 mg/kg choline chloride in AIN76A) prenatally on embryonic days 10-22, on postnatal days (PD) 25-50, or as adults from PD75 onward. Outside of these treatment periods rats were fed a standard diet (1.1 mg/kg choline chloride in AIN76A); control rats consumed only this diet throughout the study. Starting on PD100 rats' anxiety-like responses to an open field, learning in a water maze, and reactivity to forced swimming were assessed. Rats given choline supplementation during pre- or post-natal development, but not adult-treated rats, were less anxious in the open field and less immobile in the forced swim test than control rats. These effects were not mediated by a learning deficit as all groups performed comparably and well in the water maze. Thus, we offer compelling support for the hypothesis that supplemental dietary choline, at least when given during development, may inoculate an individual against stress and major psychological disorders, like depression.