Acute Fasting Does Not Induce Cognitive Impairment in Mice

Abstract

Preoperative baseline cognitive impairment is associated with postoperative neurocognitive disorder (PND). Fasting, and more generally, calorie restriction has been shown to exert controversial effects in clinical settings and various animal models of neurological disorders. Every patient needs acute fasting before anesthesia and surgery. However, the impact of acute fasting on cognitive function remain largely unknown. We, therefore, set out to determine whether acute fasting can induce neurotoxicity and neurobehavioral deficits in rodents. In the present system establishment study, a mouse model of acute fasting was established. The effects of the acute fasting on natural and learned behavior were evaluated in the buried food test, open field test and the Y maze test. The expression of c-Fos, the marker of neuronal activation, and caspase-3 activation, the marker of cellular apoptosis, were measured with immunohistochemistry. We found that the 9 h acute fasting increased the latency to eat food in the buried food test. The acute fasting also selectively increased the total distance and decreased the freezing time in open field test, and increased the duration in the novel arm in the Y maze test. Besides, the immunohistochemical study showed that the fasting significantly increased the c-Fos level in the hippocampus and various sub-cortical areas, including paraventricular thalamus (PVT), dorsomedial hypothalamus (DMH), lateral hypothalamus (LH), and basal amygdala (BMA). However, the acute fasting did not induce apoptosis, demonstrating by no appearance of caspase-3 activation in the corresponding brain areas. These data showed that acute fasting did not cause cellular apoptosis and cognitive impairment in the mice. Instead, the acute fasting increased the neuronal activity, enhanced the ambulatory activity and improved the spatial recognition memory in the mice. These findings will promote more research in the established system to further determine the effects of perioperative factors on the postoperative neurocognitive function and the underlying mechanisms.

Surgery, Anesthesia and Intensive Care Environment Induce Delirium-Like Behaviors and Impairment of Synaptic Function-Related Gene Expression in Aged Mice

“…The BFT assesses mice' olfactory memory by exploiting their reliance upon olfactory clues to forage for food (Lehmkuhl et al, 2014;Peng et al, 2016;Zheng et al, 2019). By testing for mice's ability to find a hidden cereal pellet, it also evaluates for the presence of intact attention and orderly thinking (Peng et al, 2016;Zheng et al, 2019). Hence, our BFT findings support the idea that A/S/I mice developed impairments in the domains of attention and thought process.…”

“…Next, A/S/I mice took significantly longer to find a buried cereal reward in the BFT. The BFT assesses mice' olfactory memory by exploiting their reliance upon olfactory clues to forage for food (Lehmkuhl et al, 2014;Peng et al, 2016;Zheng et al, 2019). By testing for mice's ability to find a hidden cereal pellet, it also evaluates for the presence of intact attention and orderly thinking (Peng et al, 2016;Zheng et al, 2019).…”

Urinary Catheterization Induces Delirium-Like Behavior Through Glucose Metabolism Impairment in Mice

“…We performed the Y-maze test as described in the previous studies. 19,20,24 The mouse was given free access to all 3 arms for 5 minutes. The time spent and the number of entries into the novel arms indicated the spatial recognition memory (learned behavior).…”

“…The buried food test was performed as described in previous studies. 19,20,24 Latency was defined as the duration from when the mouse was placed in the test cage until the mouse uncovered the sweetened pellet.…”

State impulsivity amplifies urges without diminishing self-control

“…That is, whether hunger could increase impulsive behaviour in response to impulses other than those that relate to food. There is substantial evidence that hunger increases impulsive behaviour more generally in non-human animals (Anderberg et al, 2016;Laude et al, 2012; but see Zheng et al, 2019), although until recently a similar domain-general effect had not been convincingly shown in human laboratory studies (Benau et al, 2014). Since then, growing evidence suggests that there is potential for a domain-general effect of hunger: people are more likely to choose an impulsive option when gambling hungry (Li et al, 2020), they are more likely to acquire non-food items (Xu et al, 2015), and the effect of hunger on delay discounting (i.e., that hungry people discount delays more) spills over into non-food domains, but the effect size is a quarter of that for food stimuli (Skrynka & Vincent, 2019).…”