Alteration of fear behaviors in sleep-deprived adolescent rats: increased fear expression and delayed fear extinction

Perception and production of second-level temporal intervals are critical in several behavioral and cognitive processes, including adaptive anticipation, motor control, and social communication. These processes are impaired in several neurological and psychological disorders, such as Parkinson’s disease and attention-deficit hyperactivity disorder. Although evidence indicates that second-level interval timing exhibit circadian patterns, it remains unclear whether the core clock machinery controls the circadian pattern of interval timing. To investigate the role of core clock molecules in interval timing capacity, we devised a behavioral assay called the interval timing task to examine prospective motor interval timing ability. In this task, the mouse produces two separate nose pokes in a pretrained second-level interval to obtain a sucrose solution as a reward. We discovered that interval perception in wild-type mice displayed a circadian pattern, with the best performance observed during the late active phase. To investigate whether the core molecular clock is involved in the circadian control of interval timing, we employed Bmal1 knockout mice (BKO) in the interval timing task . The interval production of BKO did not display any difference between early and late active phase, without reaching the optimal interval production level observed in wild-type. In summary, we report that the core clock gene Bmal1 is required for the optimal performance of prospective motor timing typically observed during the late part of the active period.

Section: Discussionmentioning

confidence: 99%

Core clock gene, Bmal1 , is required for optimal second-level interval production

Kim,

Choe

2023

“…Behavioral analysis was performed blindly by more than two experimenters. The percentages of open arm entries (open/total entries × 100) and the time spent in the open arms (open/[open + close time] × 100) were calculated for each rat (Jung and Noh 2021 ).…”

Section: Methodsmentioning

confidence: 99%

Oxytocin-induced anxiogenic behavior in juvenile male rats

Jang

Jung

Kang

et al. 2021

Self Cite

Oxytocin (OT) is considered beneficial to mental health owing to its anxiolytic, prosocial, and anti-stress effects; however, the adverse effects of OT have been controversial, such as its potentially anxiogenic actions. Although OT influences drug abuse and reciprocally affects vulnerability to drug use, the relationship between OT’s anxiogenic working and nicotine preference intake has not been clearly defined. To clarify this issue, the effect of acute peripheral administration of OT on anxiety and nicotine preference was investigated in juvenile male rats. Anxiogenic behaviors were noticeably increased in OT-administrated rats, with an increase in serum corticosterone levels. Moreover, increased anxiety-like behaviors and corticosterone levels were observed in the OT analog carbetocin-injected rats. In the nicotine preference test, the rats’ aversive responses to initial nicotine choice and preference were not significantly different between saline-injected and OT-injected rats. However, when administered with OT, there was a significant negative correlation between anxiety-like behavior and low-dose nicotine consumption. Collectively, these results provide evidence that acute OT exposure could induce anxiogenic behavior with corticosterone augmentation, contributing to the attenuation of nicotine preference. This suggests that both aspects of OT, as well as their benefits and drawbacks, should be considered.

“…Sleep is a necessary behavior to maintain an animal’s physical and cognitive health. Poor sleep quality is associated with high risk of serious medical conditions, including obesity (Beccuti and Pannain 2011 ), insulin resistance and diabetes (Knutson and Van Cauter 2008 ), coronary heart disease (Meisinger et al 2007 ; Phillips and Mannino 2007 ), and mental health issues (Alvaro et al 2013 ; Hwang et al 2019 ; Freeman et al 2020 ; Jung and Noh 2021 ). Fragmented sleep with age adversely affects human health (Carskadon et al 1982 ; Ancoli-Israel 2009 ).…”

Section: Introductionmentioning

confidence: 99%

Short-term maintenance on a high-sucrose diet alleviates aging-induced sleep fragmentation in drosophila

Lee

Kim

2021

Sleep is a fundamental behavior in an animal’s life influenced by many internal and external factors, such as aging and diet. Critically, poor sleep quality places people at risk of serious medical conditions. Because aging impairs quality of sleep, measures to improve sleep quality for elderly people are needed. Given that diet can influence many aspects of sleep, we investigated whether a high-sucrose diet (HSD) affected aging-induced sleep fragmentation using the fruit fly, Drosophila melanogaster . Drosophila is a valuable model for studying sleep due to its genetic tractability and many similarities with mammalian sleep. Total sleep duration, sleep bout numbers (SBN), and average sleep bout length (ABL) were compared between young and old flies on a normal sucrose diet (NSD) or HSD. On the NSD, old flies slept slightly more and showed increased SBN and reduced ABL, indicating increased sleep fragmentation. Short-term maintenance of flies in HSD (up to 8 days), but not long-term maintenance (up to 35 days), suppressed aging-induced sleep fragmentation. Our study provides meaningful strategies for preventing the deterioration of sleep quality in the elderly.