Food restriction induces functional resilience to sleep restriction in rats

Abstract

Study Objectives Sleep restriction (SR) leads to performance decrements across cognitive domains but underlying mechanisms remain largely unknown. The impact of SR on performance in rodents is often assessed using tasks in which food is the reward. Investigating how the drives of hunger and sleep interact to modulate performance may provide insights into mechanisms underlying sleep loss-related performance decrements. Methods Three experiments were conducted in male adult Wistar rats to assess: (1) effects of food restriction on performance in the simple response latency task (SRLT) across the diurnal cycle (n = 30); (2) interaction of food restriction and SR (11 h) on SRLT performance, sleep electroencephalogram, and event-related potentials (ERP) (n = 10–13); and (3) effects of food restriction and SR on progressive ratio (PR) task performance to probe the reward value of food reinforcement (n = 19). Results Food restriction increased premature responding on the SRLT at the end of the light period of the diurnal cycle. SR led to marked impairments in SRLT performance in the ad libitum-fed group, which were absent in the food-restricted group. After SR, food-restricted rats displayed a higher amplitude of cue-evoked ERP components during the SRLT compared with the ad libitum group. SR did not affect PR performance, while food restriction improved performance. Conclusions Hunger may induce a functional resilience to negative effects of sleep loss during subsequent task performance, possibly by maintaining attention to food-related cues.

Sleep deprivation and the rodent psychomotor vigilance test (rPVT): Assessing lapses in attention, the response stimulus interval effect, and time on task in rats using food reinforcement

“…Significant time-on-task effects were found for lapses, percent correct responses, and Q90 reaction times for the rPVT, and SD increased these measures overall (but not in a time bin-dependent manner). These effects are similar to those reported by Loomis and colleagues (2020), in addition to previous rPVT reports employing water restriction and reinforcement (Christie et al, 2008; Deurveilher et al, 2015; Oonk et al, 2015). Finally, while SD did increase Q90 reaction times on the rPVT, it did not significantly affect mean, median, or Q10 reaction times.…”

“…Loomis and colleagues (2020) recently reported that food restriction results in functional resilience to SD when compared to ad lib feeding conditions using a simple response latency task (SRLT), where rats are required to monitor the location of a randomly occurring light stimulus. The rPVT and SRLT are similar, but there are important methodological considerations that likely increased sensitivity of the rPVT to the impairing effects of sleep deprivation in food-restricted rats.…”

“…We previously compared performances on each version, and noted that high performance levels (e.g., high percentage of correct responses, low numbers of premature responses) provided good baselines to assess drug and stressor effects (Davis et al, 2016). Importantly, food restriction and reinforcement appear to attenuate the effects of SD on attention tests in rodents (Loomis et al, 2020), with many studies utilizing water restriction and reinforcement for this reason.…”