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. 2015 Jul;40(6):373-9.
doi: 10.1093/chemse/bjv009. Epub 2015 Apr 8.

CALHM1 Deletion in Mice Affects Glossopharyngeal Taste Responses, Food Intake, Body Weight, and Life Span

Göran Hellekant  1 , Jared Schmolling  2 , Philippe Marambaud  3 , Teresa A Rose-Hellekant  2
Affiliations

CALHM1 Deletion in Mice Affects Glossopharyngeal Taste Responses, Food Intake, Body Weight, and Life Span

Göran Hellekant et al. Chem Senses. 2015 Jul.

Abstract

Stimulation of Type II taste receptor cells (TRCs) with T1R taste receptors causes sweet or umami taste, whereas T2Rs elicit bitter taste. Type II TRCs contain the calcium channel, calcium homeostasis modulator protein 1 (CALHM1), which releases adenosine triphosphate (ATP) transmitter to taste fibers. We have previously demonstrated with chorda tympani nerve recordings and two-bottle preference (TBP) tests that mice with genetically deleted Calhm1 (knockout [KO]) have severely impaired perception of sweet, bitter, and umami compounds, whereas their sour and salty tasting ability is unaltered. Here, we present data from KO mice of effects on glossopharyngeal (NG) nerve responses, TBP, food intake, body weight, and life span. KO mice have no NG response to sweet and a suppressed response to bitter compared with control (wild-type [WT]) mice. KO mice showed some NG response to umami, suggesting that umami taste involves both CALHM1- and non-CALHM1-modulated signals. NG responses to sour and salty were not significantly different between KO and WT mice. Behavioral data conformed in general with the NG data. Adult KO mice consumed less food, weighed significantly less, and lived almost a year longer than WT mice. Taken together, these data demonstrate that sweet taste majorly influences food intake, body weight, and life span.

Keywords: CALHM1; Q fibers; S fibers; bitter; food intake; glossopharyngeal nerve; life span; mouse; obesity; overweight; sweet; taste; umami.

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Figures

Figure 1.
Figure 1.
Behavioral results of ≥48-h TBP tests in CALHM1 KO and WT mice. The y-axis displays the mean preference ratio in percentage of total intake of each tastant listed in Table 1. Asterisks indicate statistically significant differences between the mean responses of the 2 mouse groups (*P < 0.05). Error bars represent SE. The plot shows that significant differences between umami and sweet compounds were present in KO mice compared with WT. With regard to bitter tastants, there was a significant difference in preference for DB between KO and WT mice.
Figure 2.
Figure 2.
Summated responses of NG nerve of a WT mouse (top trace) and a KO mouse (bottom trace) during 10-s stimulation with salt (NaCl), sweet (SC45647, acesulfame-K, sucrose, and saccharin), sour (citric acid), bitter (QHCl), and umami (IMP and MSG) compounds. The recordings are consecutive with 20 s of the trace during rinsing between stimulations removed to save space. The binary code of the bottom line shows when and how long each stimulus was applied.
Figure 3.
Figure 3.
Each pair of staples represents averages of 9 summated NG recordings in WT and KO mice to the compounds denoted below. The responses of each mouse were normalized to the NH4Cl response. Asterisks denote a significant difference. The data show that although there was a significant difference between the responses of WT and KO mice to sweet and bitter (P < 0.05), no significant difference could be recorded in the responses to the salty and sour stimuli between WT and KO mice.
Figure 4.
Figure 4.
The staples illustrate weekly food intake of WT and KO mice measured over 12 weeks. The data indicate that KO mice consumed less food than WT mice (P = 0.0822).
Figure 5.
Figure 5.
The staples summarize mean body weight of adult KO mice and WT littermates <1 year and >1 year of age. Data show that the difference between KO and WT mice increased with age and became significant after 1 year (P < 0.05).
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References

    1. Adler E, Hoon MA, Mueller KL, Chandrashekar J, Ryba NJ, Zuker CS. 2000. A novel family of mammalian taste receptors. Cell. 100:693–702. - PubMed
    1. Adrian ED, Zotterman Y. 1926. The impulses produced by sensory nerve-endings. J Physiol. 61:151–171. - PMC - PubMed
    1. Andersson B, Landgren S, Olsson L, Zotterman Y. 1950. The sweet taste fibres of the dog. Acta Physiology Scand 21:105–119. - PubMed
    1. Barretto RP, Gillis-Smith S, Chandrashekar J, Yarmolinsky DA, Schnitzer MJ, Ryba NJ, Zuker CS. 2015. The neural representation of taste quality at the periphery. Nature. 517:373–376 - PMC - PubMed
    1. Brouwer JN, Glaser D, Hard Af Segerstad C, Hellekant G, Ninomiya Y, Van der Wel H. 1983. The sweetness-inducing effect of miraculin; behavioural and neurophysiological experiments in the rhesus monkey Macaca mulatta . J Physiol. 337:221–240. - PMC - PubMed

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