It is important to learn about changes in both taste and odor perceptions with increasing age, because the taste of foods we encounter in our daily life is strongly affected by their smell. This study discusses the difference in qualitative taste and odor discrimination between the elderly and the young. Tastants and odorants used in this study were presented not as single stimuli but as a taste mixture (sucrose and tartaric acid) and an odor mixture (beta-phenylethyl alcohol and gamma-undecalactone). The results showed that quality discrimination abilities of the elderly subjects for both taste and odor were significantly lower than those of the young subjects, indicating a decline in quality discrimination abilities related to age. Also, a moderate but significant correlation was observed between the taste discrimination ability and the odor discrimination ability. We measured thresholds for single-taste and odor components in mixtures and compared them between the elderly and the young to investigate the cause for these findings.

Gustatory activated regions in the cerebral cortex have not been identified precisely in humans. In this study we recorded the magnetic fields from the brain in response to two tastants, 1 M NaCl and 3 mM saccharin. We estimated the location of areas activated sequentially after the onset of stimulation with magnetic source imaging. We investigated the primary gustatory area (area G) precisely, and found it at the transition between the parietal operculum and the insular cortex. The central sulcus was activated less frequently than area G but with almost the same latency in cases of NaCl stimulation. Following area G, we found activation in several cortical regions, e.g. both the frontal operculum and the anterior part of the insula, the hippocampus, the parahippocampal gyrus and the superior temporal sulcus.

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We have previously shown that the oral administration of heat-killed Lactobacillus brevis (L. brevis) SBC8803 strain inhibits IgE production in ovalbumin (OVA)-sensitized BALB/c mice through improvement of the type-1 helper T (Th1)/Th2 balance toward Th1 dominance. Atopic dermatitis is one of the most common skin diseases and is frequently associated with elevated immunoglobulin E (IgE) antibodies against many kinds of allergens. In this study, we investigated the inhibitory effect of oral administration of L. brevis SBC8803 on the development of dermatitis and IgE elevation using the NC/Nga atopic dermatitis model mice. Male 8-week-old NC/Nga mice were sensitized by the topical application of picryl chloride to foot pads and shaved abdomen. These mice were boosted with picryl chloride by topical application onto the ears once a week for 9 weeks. The mice (n‫01؍‬ per group) were fed a diet containing 0%, 0.05% or 0.5% of heat-killed L. brevis SBC8803 from 2 weeks before the first sensitization to the end of the study. Total IgE concentration in serum, clinical score, and ear thickness were periodically examined throughout the study.

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