Food neophobia in wild and laboratory rats (multi-strain comparison)

Abstract

Although empirical studies comparing neophobia in wild and laboratory rats have been conducted in the past, a few decades have passed since most of them were completed. This is a substantial period of time in the case of fast-breeding animals such as rats. Equally important are the inconsistencies in research findings with respect to comparisons between wild and laboratory rats, and within domesticated strains. As well as having the aim of updating knowledge of neophobia among different types of rats, the present experiment was also an attempt to isolate a specific fear of a new food from a general fear of a novel object. The procedure was that rats accustomed to one type of food served in a specific location and in a familiar container were given a different type of food. Test trials were preceded by food deprivation. The following variables were measured: feeding latency, the pace of eating, the number of approaches to the container, and the number of times food was sampled in each trial. The amount of food consumed in each trial was weighed and also taken into account. Grooming time served as the measure of stress among the rats in the experiment. The results of the experiment did not confirm the assertion of some authors that wild rats avoid eating unfamiliar foods. All groups demonstrated only a temporary decrease in the amount of food consumed, the magnitude of which was similar in all strains. No evidence of particularly low neophobia in albino rats was found. However, the behavioral symptoms indicated higher levels of stress in wild rats compared to the other groups.

Glucocorticoids Mediate Short-Term High-Fat Diet Induction of Neuroinflammatory Priming, the NLRP3 Inflammasome, and the Danger Signal HMGB1

“…Interestingly, rats that were fed the control diet also exhibited a significant increase compared with rats fed the regular diet, suggesting that at least a portion of the increased body mass exhibited by the HFD group could be attributed to the novelty of the diet, as the consumption of a novel diet has been shown to induce weight gain after an initial (1 d) period of neophobia (Eckel and Ossenkopp, 1993; Modlinska et al, 2015). Taking this factor into account, the HFD group gained 1% body weight above that of the control diet group.…”

Maternal nicotine exposure during lactation alters food preference, anxiety-like behavior and the brain dopaminergic reward system in the adult rat offspring

“…Thus, SSD groups demonstrated low resistance to the new food. Modlinska et al [72] also showed that rats did not avoid eating unfamiliar foods, displaying only a temporary reduction in the amount of the new food consumed. In fact, both SSD groups in the present study ingested a greater amount of palatable diet in the first exposure (PN150), rendering unlikely the possibility of neophobia regarding the diets used here.…”

Neural connectivity between the hypothalamic supramammillary nucleus and appetite‐ and motivation‐related regions of the rat brain

“…This increase was observed in cells that were not TH‐positive, although it occurred regardless of whether the rat consumed the SCM. It is difficult to interpret this observation, although it may point to a role for the SuMM in learning and/or the physiological response in food neophobia …”