Regional changes in brain histamine levels following dietary-induced thiamine deficiency in rats.

Histamine levels in thiamine deficient rats were significantly lower in the hippocampus, amygdala, olfactory bulb, thalamus and pons-medulla oblongata than those of normal and pair-fed groups. In the case of the hypothalamus, thiamine deficiency produced a significant increase in histamine levels. These changes observed in the thiamine deficient group were reversed to the normal levels by supplying the normal diet. These data present a new finding that thiamine deficiency affects the central histaminergic neuron system as well as other monoaminergic systems.