[Vitamin d alterations in food regimens and synaptic transmission in neuronal circuit]

ABSTRACT

In nervous system, through specific channels and some ionotropic receptors, calcium ion involves in synaptic transmission vitamin D takes an important role in cellular regulation as well. Calcium ion plays an important role in synaptic transmission through specific channels and some receptors such as NMDA receptors in the nervous system. In the present study we asked if alterations in vitamin D content of food regimens influence electrophysiological phenomena in hippocampal neuronal circuits. Adult rats under normal food regimen [CON], vitamin-D-free regimen [CON-D] or with a supplement of calcitriol [CON+D] were used in this study. Stimulating Schaffer colateral excitatory post synaptic field potentials [EPSP] were recorded in CA1 area of hippocampus. For inducing of long term potentiation [LTP] high frequency stimulation [HFS] was used as a tetanic stimulation. Changes in the amplitude of EPSPs were considered for comparison of the 3 tested groups. Our findings indicated that there was no difference between EPSP amplitude of the CON, CON+D and CON-D rats. On the other hand, LTP was induced only in the CON and CON+D animals. According to the findings, it seems that vitamin D deficiency considerably affect potentiation of the synaptic transmission. The probable mechanism can be vitamin D regulation of intracellular calcium concentration