Foakes C, Lawrence-Sidebottom D, Dralega AT, Harvey DO, Schmidt MA, Davis CJ. The rat Lux Actuating Search Task (LAST) and effects of sleep deprivation on task reversal performance.
Neurobiol Sleep Circadian Rhythms 2022;
13:100081. [PMID:
35989719 PMCID:
PMC9388875 DOI:
10.1016/j.nbscr.2022.100081]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 08/10/2022] [Accepted: 08/10/2022] [Indexed: 11/30/2022] Open
Abstract
Sleep deprivation (SD) causes significant deficits in multiple aspects of cognition, including sustained attention and working memory. Investigating the neural processes underpinning these cognitive losses has proven challenging due to the confounds of current animal tasks; many employ appetitive or aversive stimuli to motivate behavior, while others lack task complexity that translates to human studies of executive function. We established the Lux Actuating Search Task (LAST) to circumvent these issues. The LAST is performed in a circular, open-field arena that requires rats to find an unmarked, quasi-randomly positioned target. Constant low-level floor vibrations motivate ambulation, while light intensity (determined by the rodent's proximity to the target destination) provides continuous visual feedback. The task has two paradigms that differ based on the relationship between the light intensity and target proximity: the Low Lux Target (LLT) paradigm and the High Lux Target paradigm (HLT). In this study, on days 1–6, the rats completed nine trials per day on one of the two paradigms. On day 7, the rats were either sleep deprived by gentle handling or were left undisturbed before undertaking the opposite (reversal) paradigm on days 7–9. Our results showed that SD significantly impeded the ability of Long Evans rats to learn the reversal paradigm, as indicated by increased times to target and increased failure percentages compared to rats whose sleep was undisturbed. Rats also showed reduced learning with the HLT paradigm, as the initial task or as the reversal task, likely due to the rodents' photophobia limiting their motivation to navigate toward a bright light, which is required to succeed.
A continuous feedback paradigm examining the effects of sleep loss on cognitive flexibility in rats is introduced.
Floor vibrations motivate and variable light intensity directs navigation to an unmarked location in an open field arena.
The reversal of light intensity cues from light to dark and vice versa is disrupted by sleep deprivation.
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