Buried Food-seeking Test for the Assessment of Olfactory Detection in Mice

Abstract

The sense of smell allows animals to discriminate a large number of volatile environmental chemicals. Such chemical signaling modulates the behavior of several species that depend on odorant compounds to locate food, recognize territory, predators, and toxic compounds. Olfaction also plays a role in mate choice, mother-infant recognition, and social interaction among members of a group. A key assay to assess the ability to smell odorants is the buried food-seeking test, which checks whether the food-deprived mice can find the food pellet hidden beneath the bedding in the animal's cage. The main parameter observed in this test is the latency to uncover a small piece of chow, cookie, or other pleasant food, hidden beneath a layer of cage bedding, within a limited amount of time. It is understood that foodrestricted mice which fail to use odor cues to locate food within a given time period are likely to have deficits in olfactory abilities. Investigators who used the buried food test, or versions of the buried food test, demonstrated that it is possible to evaluate olfactory deficits in different models of murine studies

CUL3 Deficiency Causes Social Deficits and Anxiety-like Behaviors by Impairing Excitation-Inhibition Balance through the Promotion of Cap-Dependent Translation

“…We crossed Cul3 f/f mice with GFAP::Cre mice that express Cre under the promoter of GFAP, a gene that is expressed in neural progenitor cells of both neurons and astrocytes (Kriegstein and Alvarez-Buylla, 2009;Noctor et al, 2001;Zhuo et al, 2001). Cre in GFAP-Cre mice is expressed in the majority of projection neurons in the hippocampus (99%) and cortex (88%) (Madisen et al, 2010;Malatesta et al, 2003;Zhuo et al, 2001). Cul3 level was reduced in a gene-dosage-dependent manner in Cul3 f/+ , GFAP-Cul3 f/+ , or GFAP-Cul3 f/f mice (Figure S1A).…”

“…Buried food-seeking test was performed as described previously (Machado et al, 2018). Mice were food deprived for 24 h before the test.…”

Olfactory dysfunction in the 3xTg-AD model of Alzheimer’s disease

“…When working with an AD mouse model that has been shown to have memory and cognitive decline beginning at 4 months of age ( Billings et al, 2005 ) and numerous anxiety behaviors, such as increased restlessness and increased startle responses ( Sterniczuk et al, 2010b ), a reduction in handling and learning of new tasks is another advantage of the BFT. Using food pellets that the mice have been exposed to repeatedly, in addition to the acclimation period the mice were given before the food was buried, have both been shown to reduce anxiety and novelty induced hypophagia, which is the inhibition of feeding that can occur when exposed to a novel food ( Machado et al, 2018 ).…”

“…In comparison to newer olfactory tests, the BFT has advantages such as a pre-test acclimation period (to reduce anxiety and novelty-induced exploration of the test cage). Furthermore, the buried food odorant used in the BFT is the same chow the mice have been given throughout their lifespan, which can reduce novelty-induced hypophagia ( Machado et al, 2018 ). The BFT is based on an innate behavior of mice (foraging for food), and the use of novel rewards, such as artificially flavored cereal instead of the familiar mouse chow, has been shown to produce different foraging behavior ( Machado et al, 2018 ).…”

“…Furthermore, the buried food odorant used in the BFT is the same chow the mice have been given throughout their lifespan, which can reduce novelty-induced hypophagia ( Machado et al, 2018 ). The BFT is based on an innate behavior of mice (foraging for food), and the use of novel rewards, such as artificially flavored cereal instead of the familiar mouse chow, has been shown to produce different foraging behavior ( Machado et al, 2018 ). Lastly, the BFT was used as a means to determine if the 3xTg-AD mice could actually detect odors; if the mice could not detect smells, then other tests of olfactory abilities would have produced inconclusive results.…”