Vitamin C has been shown to have a key function in the brain, and during states of deficiency it is able to retain higher concentrations of vitamin C than other organs. However, because neurons maintain one of the highest intracellular concentrations of vitamin C in the organism, the brain may still be more sensitive to deficiency despite these preventive measures.
Objective: The objective was to study the potential link between chronic vitamin C deficiency and neuronal damage in newborn guinea pigs.
Design: Thirty 6- to 7-d-old guinea pigs were randomly assigned
to 2 groups to receive either a vitamin C-sufficient diet or the same diet containing a low concentration of vitamin C (but adequate to prevent scurvy) for 2 mo. Spatial memory was assessed selleck chemical by the Morris Water Maze, and hippocampal neuron numbers were quantified by stereologic techniques.
Results: The results showed a reduction in spatial memory (P < 0.05) and an increased time to first platform hit (P < 0.05) in deficient animals compared with controls. The deficient animals had a lower total number of neurons in hippocampal subdivisions Selleckchem PLX 4720 (dentate gyrus, cornu
ammonis 1, and cornu ammonis 2-3) than did the normal controls (P < 0.05).
Conclusions: Our data show that vitamin C deficiency in early postnatal life results in impaired neuronal development and a functional decrease in spatial memory in guinea pigs. We speculate that this unrecognized effect of vitamin C deficiency may have clinical implications for high-risk individuals, such as in children born from vitamin C-deficient mothers. Am J Clin Nutr 2009;90:540-6.”
“Local disordering has been analyzed in ordered intermetallic
CoAl films epitaxially grown on GaAs(001) AG-14699 substrates by molecular beam epitaxy. Transmission electron microscopy investigations demonstrate the appearance of the bcc phase in the CoAl epilayer, which is the disordered version of the B2 crystal lattice type. Variations in the growth temperature between 100 and 300 degrees C reveal that the degree of thermal disordering and the volume fraction of the disordered bcc phase increase with increasing temperature. Interface reactions were observed in the sample fabricated at 300 degrees C resulting in the formation of CoAs precipitates at the interface. These precipitates contribute to the plastic relaxation of the 1.2% lattice mismatch between the CoAl film and the GaAs substrate affecting the strain-induced order-disorder transition. The impact of disordering is discussed in connection to the high diffusivity of vacancies and Co atoms existing in the intermetallic alloy. (C) 2010 American Institute of Physics. [doi:10.1063/1.