Biology subjects

Tordoff, M. G.

Publications and source records attributed to Tordoff, M. G..

3 recordsLinked to original sources

bioRxiv2023

Short-term consumption of ultra-processed semi-synthetic diets impairs the sense of smell and brain metabolism in mice

The prevalence of highly-palatable, ultra-processed food in our modern diet has exacerbated obesity rates and contributed to a global health crisis. While accumulating evidence suggests that chronic consumption of ultra-processed semi-synthetic food is detrimental to sensory and neural physiology, it is unclear whether its short-term intake has adverse effects. Here, we assessed how short-term consumption (<2 months) of three ultra-processed diets (one grain-based diet, and two semi-synthetic) influence olfaction and brain metabolism in mice. Our results demonstrate that short-term consumption of semi-synthetic diets, regardless of macronutrient composition, adversely affect odor-guided behaviors, physiological responses to odorants, transcriptional profiles in the olfactory mucosa and brain regions, and brain glucose metabolism and mitochondrial respiration. These findings reveal that even short periods of ultra-processed semi-synthetic food consumption are sufficient to cause early olfactory and brain abnormalities, which has the potential to alter food choices and influence the risk of developing metabolic disease.

neuroscience↗

bioRxiv2021

Understanding the Evolution of Nutritive Taste in Animals: Insights from Biological Stoichiometry and Nutritional Geometry

A major conceptual gap in taste biology is the lack of a general framework for understanding the evolution of different taste modalities among animal species. We turn to two complementary nutritional frameworks, biological stoichiometry theory and nutritional geometry, to develop hypotheses for the evolution of different taste modalities in animals. We describe how the attractive tastes of Na, Ca, P, N and C containing compounds are consistent with principles of both frameworks based on their shared focus on nutritional imbalances and consumer homeostasis. Specifically, we suggest that the evolution of multiple nutritive taste modalities can be predicted by identifying individual elements that are typically more concentrated in the tissues of animals than plants. Additionally, we discuss how consumer homeostasis can inform our understanding of why some taste compounds (i.e., Na, Ca and P salts) can be either attractive or aversive depending on concentration. We also discuss how these complementary frameworks can help to explain the phylogenetic distribution of different taste modalities and improve our understanding of the mechanisms that lead to loss of taste capabilities in some animal lineages. The ideas presented here will stimulate research that bridges the fields of evolutionary biology, sensory biology and ecology.

evolutionary biology↗

bioRxiv2018

Genetics of mouse Tas1r3-independent sucrose intake

We have previously shown that variation in sucrose intake among inbred mouse strains is due in part to polymorphisms in the Tas1r3 gene, which encodes a sweet taste receptor subunit and accounts for the Sac locus on distal Chr4. To discover other quantitative trait loci (QTLs) influencing sucrose intake, voluntary daily sucrose intake was measured in an F2 intercross with the Sac locus fixed; in backcross, reciprocal consomic strains; and in single- and double-congenic strains. Chromosome mapping identified Scon3, located on Chr9, and epistasis of Scon3 with Scon4 on Chr1. Mice with different combinations of Scon3 and Scon4 genotypes differed more than threefold in sucrose intake. To understand how these two QTLs influenced sucrose intake, we measured resting metabolism, glucose and insulin tolerance, and peripheral taste responsiveness in congenic mice. We found that the combinations of Scon3 and Scon4 genotypes influenced thermogenesis and the oxidation of fat and carbohydrate. Results of glucose and insulin tolerance tests, peripheral taste tests, and gustatory nerve recordings ruled out plasma glucose homoeostasis and peripheral taste sensitivity as major contributors to the differences in voluntary sucrose consumption. Our results provide evidence that these two novel QTLs influence mouse-to-mouse variation in sucrose intake and that both likely act through a common postoral mechanism.

animal behavior and cognition↗