Effects of maternal restriction in vitamin B-6 on neocortex development in rats: neuron differentiation and...

Effects of maternal restrictions in vitamin B-6 on neuron differentiation and synaptogenesis in developing neocortex were examined. Rats were fed ad libitum a vitamin B-6-free diet supplemented with 0.0 or 0.6 mg pyridoxine hydrochloride (PN.HCl)/kg diet during gestation followed by a control level of 7.0 mg/kg diet during lactation, or they were fed the vitamin B-6-free diet supplemented with 0.6 or 7.0 mg PN.HCl/kg diet throughout gestation and lactation. Neocortices of the offspring were examined at 30 d of age by light and electron microscopy. All maternal restrictions in vitamin B-6 reduced the number of higher order dendrites on stellate neurons in layer II and on pyramidal neurons in layer V of the neocortex and decreased synaptic density in the neuropil of the neocortex. The findings indicated that vitamin B-6 restriction during gestation, either marginal or severe, was the critical treatment factor that adversely affected synaptogenesis and at least one event in neuron differentiation in the neocortex, the arborization of dendrites.