Sweet and Bitter Taste of Ethanol in C57BL/6J and DBA2/J Mouse Strains

Abstract

Studies of inbred strains of rats and mice have suggested a positive association between strain variations in sweet taste and ethanol intake. However, strain associations by themselves are insufficient to support a functional link between taste and ethanol intake. We used conditioned taste aversion (CTA) to explore the sweet and bitter taste of ethanol and ability to detect sucrose, quinine and ethanol in C57BL/6J (B6) and DBA/2J (D2) mouse strains that are frequently used in alcohol research. The present study showed that C57BL/6J mice generalized taste aversions from sucrose and quinine solutions to 10% ethanol and, reciprocally, aversions to 10% ethanol generalized to each of these solutions presented separately. Only conditioned aversions to quinine generalized to ethanol in the DBA/2J strain but an aversion conditioned to ethanol did not generalize reciprocally to quinine. Thus, considering these two gustatory qualities, 10% ethanol tastes both sweet and bitter to B6 mice but only bitter to D2. Both strains were able to generalize taste aversions across different concentrations of the same compound. B6 were able to detect lower concentrations of quinine than D2 but both strains were able to detect sucrose and (in contrast to previous findings) ethanol at similar concentrations. The strain-dependent gustatory profiles for ethanol may make an important contribution to the understanding of the undoubtedly complex mechanisms influencing high ethanol preference of B6 and pronounced ethanol avoidance of D2 mice.

A grandparent-influenced locus for alcohol preference on mouse chromosome 2

“…Mouse inbred strains differ in taste perception [35]. As ethanol at concentrations greater than 10% is considered bitter for mice [34], it is therefore important to consider differences in taste perception between strains [36]. We show that CSS-2 mice are indistinguishable from C57BL/6J mice in preference for bitter solutions (quinine), sweet noncaloric solutions (saccharin) or sweet solutions isocaloric to 15% ethanol (sucrose).…”

“…Preference for non-ethanol tastants in CSS-2 and C57BL/6J mice Ethanol at concentrations greater than 10% is considered bitter for mice [34]. In oral self-administration setups, it is therefore important to compare strains or treatment groups for taste sensitivity using sweet and bitter nonethanol tastants.…”

Strain differences in the neural, behavioral, and molecular correlates of sweet and salty taste in naive, ethanol- and sucrose-exposed P and NP rats

“…Only conditioned aversions to quinine generalized to ethanol in DBA/2J mice, but an aversion conditioned to ethanol did not generalize reciprocally to quinine. Thus, considering these two gustatory qualities, 10% ethanol tastes both sweet and bitter to C57BL/6J mice but only bitter to DBA/2J mice (Blizard 2007). In contrast, in outbred rats sucrose and quinine aversions did generalize to various alcohol concentrations, but ethanol did not generalize to sucrose and quinine but only to mixtures of these compounds (Blizard 2007;Kiefer and Lawrence 1988;Kiefer and Mahadevan 1993;Lawrence and Kiefer 1987).…”

“…Thus, considering these two gustatory qualities, 10% ethanol tastes both sweet and bitter to C57BL/6J mice but only bitter to DBA/2J mice (Blizard 2007). In contrast, in outbred rats sucrose and quinine aversions did generalize to various alcohol concentrations, but ethanol did not generalize to sucrose and quinine but only to mixtures of these compounds (Blizard 2007;Kiefer and Lawrence 1988;Kiefer and Mahadevan 1993;Lawrence and Kiefer 1987). These studies suggest that in some inbred strains ethanol has both a sweet taste quality and a bitter taste quality and is thus expected to interact with both sweet and bitter taste transduction pathways.…”

Conditioned context aversion learning in the laboratory mouse

“…While studying CTA in mice (Blizard, 2007;Blizard & McClearn, 2000), control mice (those that drank water from novel tubes) exhibited strong conditioned aversions to the novel containers following pairing with lithium chloride (LiCl), raising the possibility that they had developed aversions to the containers. The present experiments were conducted to formally examine this possibility.…”