Altered Cerebro-Cerebellar Functional Connectivity Associated with Working Memory Decline after Sleep Deprivation

doi:10.21203/rs.3.rs-4272473/v1

It has been demonstrated that the cerebellum plays a critical role not only in motor function but also in cognitive function. Numerous studies have revealed altered functional connectivity (FC) in cerebral cortex underlying working memory (WM) decline after acute sleep deprivation (SD). However, whether the altered cerebro-cerebellar functional connectivity (FC) is associated with WM impairment after acute SD remains unclear. In this study, 26 healthy participants with regular sleep performed an n-back task and underwent resting-state functional magnetic resonance imaging (fMRI) scans before and after 24 h of SD. The FC between the cerebrum and cerebellum and its relationship with WM function were analyzed in recruited participants. Our results showed a significantly longer RT for the 1-back and 2-back tasks and lower accuracy of the 2-back task after SD. We found a marked reduction in FC between ten pairs of regions in the cerebellum and cerebrum after SD. Furthermore, the altered FC between the right lobule X of the cerebellum and left precentral gyrus was positively correlated with a decline in WM performance. Our findings reveal that the disrupted FC between the cerebellum and cortical regions may contribute to the declined WM after acute SD.

sleep deprivation

cerebrum

cerebellum

functional connectivity

working memory

Sleep deprivation (SD) is very common in modern society, with a sleep duration of less than four hours on a typical 24-hour day, leading to abnormal changes in body and mood[1]. Due to unhealthy lifestyle habits and sleep disorders, SD causes a series of negative effects, especially on cognitive function, including memory impairment, lack of attention, mood changes, and slow thinking [2, 3, 4]. Working memory (WM) is a crucial component of many neurobehavioral tasks involving multiple brain areas such as the parietal lobe and cingulate cortex [5]. Notably, acute SD significantly reduces the accuracy and omission rate of WM [6, 7]. Functional magnetic resonance imaging (fMRI) is the non-invasive and essential tool to examine the underlying mechanism of declined WM after acute SD [8, 9] . Previous neuroimaging studies have demonstrated that WM function is associated with gray matter volume in the supplementary motor cortex after acute SD [10] .

Resting-state functional connectivity (FC) can reflect the effects of neural networks under some condition [11]. After SD, the altered FCs were found in the default model network, salience network, dorsal attention network, frontoparietal network, and WM network [12, 13, 14, 15]. These connections are almost cortico-cortical, whereas the cerebellum is seldom mentioned [11]. Growing evidence has revealed that the cerebellum plays a critical role not only in motor function but also in cognitive function [16]. Different regions of the cerebellum take part in different subsystems of the model of WM [17]. Higher volumes of cerebellar subregions were associated with better performance of WM, such as Crus I and VIIIa [18]. Furthermore, sleep can also help process and consolidate procedural memory which is depended on cerebellum [19, 20]. Previous studies have illustrated an abnormal cerebellum and poor memory in some sleep disorders [19, 21]. Importantly, numerous studies have suggested that SD decreases gray matter volume in the right cerebellum anterior and posterior lobes [22, 23, 24]. Moreover, several studies have reported alterations in the cerebro-cerebellar FC in WM [25, 26, 27]. whether the altered cerebro-cerebellar functional connectivity (FC) is associated with WM impairment after acute SD remains unclear.

To fill this gap, we hypothesized that altered cerebro-cerebellar FC contributes to reduced WM function after acute SD. To validate our hypothesis, we enrolled healthy participants with regular sleep and collected resting-state fMRI scans before and after 24 h of SD. Furthermore, the n-back task was used to measure WM function in enrolled participants. We then probed the relationship between the altered cerebro-cerebellar FC and WM performance in individuals with acute SD.

Participants

The sample size of our study was calculated using the G*Power (a standard effect size of 0.5 and a power of 0.8, with a error probability of 0.05) [28]. A total of 26 (13 females) healthy college students aged from 20 to 30 years (25.03 ± 1.72 years) and17.92 ± 1.38 years education duration were recruited from November 2020 to May 2021. The enrolled subjects must meet the criteria as follows: 1) Pittsburgh Sleep Quality Index (PSQI) score < 5; 2) regular sleep without excessive morning or evening types; 3) right-handed; 4) no history of neurologic or psychiatric diseases; 5) no trauma stimuli; 6) no caffeine, smoking, alcohol or drug addictions; 7) no MRI contraindications. The Ethics Committee of Beijing Anding Hospital, affiliated with Capital Medical University, approved the study protocol (number of clinical registrations: ChiCTR2000039858). Informed consent was obtained from each enrolled patient prior to the study.

Study Procedure

In line with our previous study [15], each participant visited the laboratory twice. They had to sign an informed consent form while receiving a concise overview of the study. At the second visit, the participants had to get up at 7:00 am and return to the laboratory before 8:00 am for 24 hours SD. During the study, all recruited participants remained awake and did not consume tea, alcohol, or coffee. The researchers monitored turns to ensure that each participant was awake. Our researchers would wake them up if they showed any indications of falling asleep. Each subject completed two MRI scans before and after 24 h SD, respectively. We conducted the 250 s T1 and 490 s resting-state scans during the first MRI scan and the 490-s resting-state scan during the second MRI scan around 7:00 am the following day. All subjects were reminded to stay awake during scanning, and subjects who fell asleep during the fMRI scan were excluded.

Cognitive Assessment

The n-back task was utilized in the current study to assess WM performance both before and after 24 h SD. A series of letters appeared in the center of the computer screen at the 0-back, 1-back, and 2-back levels (Fig. 1) [8]. After a blank screen for 2000 ms, the letter was displayed for 500 ms. At the 0-back level, the participants were required to respond to each trial, which acted as a control condition to modify the task. In the 1-back task, subjects had to click the mouse button on the left or right when the letters of the two consecutive trials were the same. In the 2-back task, the subjects responded if the letter was displayed two trials earlier. There were nine blocks with 270 trials in this task for 11 min using E-prime 2.0. The reaction time (RT) and accuracy of each subject in this task were estimated by a certified neuropsychologist in accordance with the standardized protocols.

MRI Acquisition

MRI was performed using a Siemens 3.0 Tesla Prisma at Beijing Anding Hospital in Beijing, China. During the MRI scan, the subjects had to remain still, keep their eyes closed, and resist falling asleep. In addition, participants were required to freeze their foam head support to avoid head movement. A single-shot, gradient-recalled echo-planar imaging sequence was used for the resting-state fMRI data. These parameters were set in accordance with previously published studies [29]. A rapid gradient-echo sequence with T1-weighted multiecho magnetization preparation was used to acquire high-resolution structural images.

Data Processing

Image processing was performed using DPABISurf developed by Yan et al [30]. A surface-based image preprocessing pipeline was used, as previously described [31], which included anatomical data preprocessing, custom methodology of fMRIPrep, bregister, slice-time corrected, resampling into standard space, and component-based noise correction. The quality control of images was screened using participants' head motion within 0.5 mm framewise displacement or 1.5 standardized DVARS.

The automated anatomical atlas 3 (AAL3) was used to extract blood-oxygen-level-dependent (BOLD) signals for 166 regions of interests (ROIs), including the 26 sub-regions (95-120 labels) of the cerebellum and 140 sub-regions of the cerebrum (1-94 and 121-166 labels) [32]. FC between any two ROI pairs was estimated using Pearson’s correlation coefficient of the BOLD signals. Next, Fisher’s z-score was used to convert the FC values.

Statistical Analysis

Repeated-measures analysis of variance (ANOVA) was conducted to analyze WM performance in the RW and SD conditions. Moreover, we conducted Pearson’s correlations between the changes in RT and accuracy of one-back and two-back tasks and the altered cerebro-cerebellar FC in the RW and SD states. The false discovery rate (FDR) was used to account for multiple comparisons (corrected to p < 0.05).

WM Performance

A total of 26 participants completed the trial and were included in the final analysis (Table 1). We performed a paired-sample t-test to compare the RT and accuracy of the one-back and two-back tasks between RW and SD states. Compared to the RW state, a significant longer RT for the one-back task was found in the SD state (p = 0.014), but not for the two-back task (p = 0.690). Task accuracy was lower in the SD state than the RW state, although there was no significant difference for the one-back task (p = 0.889), and two-back (p = 0.070) task.

Altered FC between the Cerebellum and Cerebrum after SD

Compared with the RW state, we found significantly decreased FC between 10 pairs of regions in the cerebellum and cerebrum after SD, including the right lobule X of the cerebellum and left precentral gyrus, right lobule X of the cerebellum and left amygdala, right lobule X of the cerebellum and left ventral anterior thalamus, right lobule III of the cerebellum and left ventral anterior thalamus, right lobule III of the cerebellum and left lateral posterior thalamus, right lobule III of the cerebellum and right lateral posterior thalamus, right lobule III of the cerebellum and right lateral posterior thalamus, right lobule III of the cerebellum and left intralaminar thalamus, right lobule III of the cerebellum and left reuniens of the thalamus, left lobule III cerebellum, and left ventral posterior thalamus. The details are presented in Table 2 and Fig. 2.

Correlation Analysis

We performed a correlation analysis between changes in the RT of one-back and two-back tasks and altered FC between the cerebellum and cerebrum. We found that the change in RT in the two-back task was positively correlated with the altered FC between the right lobule X of the cerebellum and the left precentral gyrus (r = 0.198, p = 0.023, Fig. 3).

In this study, we aimed to explore the altered FC between the cerebellum and cerebrum to predict WM decline after acute SD. The 10 pairs of regions between the cerebellum and cerebrum showed a significantly decreased FC after SD. Moreover, the change in FC between the right lobule X of the cerebellum and left precentral gyrus was positively correlated with a decline in WM performance. These findings indicate that altered FC between the right lobule X of the cerebellum and left precentral gyrus might predict WM impairment after acute SD.

Altered FC in the cerebrum regions is mainly involved in the thalamus, amygdala, and precentral gyrus after acute SD. The thalamus is a key node of the arousal system. A recent study revealed an increased ALFF in the thalamus after 24h SD [33]. Another study confirmed that increased FC between the thalamus and the default mode network is associated with worse WM performance [34]. These findings are consistent with our results, which indicate that alterations in thalamic activity are associated with WM performance after SD. The amygdala plays an essential role in emotional processing and contributes to fear memory consolidation after SD [35]. Importantly, increased connection strength between the amygdala and cerebellum has been confirmed to be associated with emotional enhancement of episodic memory [36]. The precentral gyrus is involved in motor functions and cognitive processing [37]. One study revealed that the FC between the putamen and bilateral precentral gyrus was significantly reduced after 36 h of SD, which may be associated with impaired motor perception [38]. Another study demonstrated decreased FC between the left hippocampal and bilateral precentral gyri during the n-back task after acute SD, which implied a role for the precentral gyrus during the WM task [39]. Taken together, these findings provide evidence for the role of these cerebral regions in cognitive and emotional processing after SD.

Our findings also showed altered FC in the cerebellar regions mainly involved in lobules III and X after acute SD. Lobule III is located in the cerebellum anterior lobe, forms functional circuits with sensorimotor areas, including the thalamus, and is responsible for motor execution [40]. It had been demonstrated that the Motor preparation and execution were impaired after acute SD [41]. Considering the altered activity of the thalamus after SD, we speculated that the decreased FC between lobule III and the subregions of the thalamus might be the neural mechanism responsible for SD-induced impaired motor execution. Lobule X is a part of the cerebellum posterior lobe, which is responsible for cognition, such as WM, language, and motor planning [40]. Several studies have confirmed that lobules VI/Crus I and VII and the right VIIIA are activated during WM tasks [42, 43]. These regions are also located in the posterior lobe of the cerebellum. Notably, the precentral gyrus and cerebellar regions were activated in healthy subjects during the Sternberg WM task [44]. Our results also revealed that the change in FC between right lobule X of the cerebellum and left precentral gyrus was positively correlated with a decline in WM performance. Hence, the decreased FC between the right lobule X of the cerebellum and the left precentral gyrus might represent the neural mechanism underlying WM impairment after acute SD. Overall, this finding is consistent with our hypothesis and provides new insights into the role of cerebro-cerebellar FC in predicting WM decline following acute SD.

However, this study had several limitations. First, only participants aged 20-30 years were recruited. Our findings cannot be extrapolated to other age groups. Healthy subjects from a broader age range should be recruited in future studies. Second, the learning effect in the n-back task should be noted, which may explain the lack of significant differences in the ACC between the SD and RW states. Further studies with separate resting control groups are required.

In conclusion, our findings revealed an association between WM performance and altered cerebro-cerebellar FC in acute SD. The altered FC between the right lobule X of the cerebellum and left precentral gyrus may contribute to the decline in WM after acute SD.

All authors have no conflicts of interest in this study.

Ethical Approval

The Ethics Committee of Beijing Anding Hospital, affiliated with Capital Medical University, approved the study protocol (number of clinical registrations: ChiCTR2000039858).

Funding

This study was supported by National Natural Science Foundation (Grant No. 81904120), the Beijing Hospital Authority Youth Program (Grant No. QML20201901), and Beijing Hospital Authority’s Ascent Plan (Grant No. DFL20191901), and the Beijing Hospital Authority Clinical Medicine Development of Special Funding (Grant No. ZYLX202129).

Availability of data and materials

The data that support the findings of this study are available on request from the corresponding author.

Hudson AN, Van Dongen HPA and Honn KA. Sleep deprivation, vigilant attention, and brain function: a review. Neuropsychopharmacology 2020: 45:21-30.
Tobaldini E, Costantino G, Solbiati M, Cogliati C, Kara T, Nobili L and Montano N. Sleep, sleep deprivation, autonomic nervous system and cardiovascular diseases. Neurosci Biobehav Rev 2017: 74:321-9.
Benarroch E. What Is the Involvement of the Cerebellum During Sleep? Neurology 2023: 100:572-7.
Lowe CJ, Safati A and Hall PA. The neurocognitive consequences of sleep restriction: A meta-analytic review. Neurosci Biobehav Rev 2017: 80:586-604.
D'Esposito M and Postle BR. The cognitive neuroscience of working memory. Annu Rev Psychol 2015: 66:115-42.
Gerhardsson A, Åkerstedt T, Axelsson J, Fischer H, Lekander M and Schwarz J. Effect of sleep deprivation on emotional working memory. J Sleep Res 2019: 28:e12744.
Baddeley A. Working memory: theories, models, and controversies. Annu Rev Psychol 2012: 63:1-29.
Cross N, Paquola C, Pomares FB, Perrault AA, Jegou A, Nguyen A, Aydin U, Bernhardt BC, Grova C and Dang-Vu TT. Cortical gradients of functional connectivity are robust to state-dependent changes following sleep deprivation. Neuroimage 2021: 226:117547.
Dai C, Zhang Y, Cai X, Peng Z, Zhang L, Shao Y and Wang C. Effects of sleep deprivation on working memory: change in functional connectivity between the dorsal attention, default mode, and fronto-parietal networks. Front Hum Neurosci 2020: 14:360.
Mu Q, Nahas Z, Johnson KA, Yamanaka K, Mishory A, Koola J, Hill S, Horner MD, Bohning DE and George MS. Decreased cortical response to verbal working memory following sleep deprivation. Sleep 2005: 28:55-67.
Chee MWL and Zhou J. Functional connectivity and the sleep-deprived brain. Progress in brain research 2019: 246:159-76.
Chen WH, Chen J, Lin X, Li P, Shi L, Liu JJ, Sun HQ, Lu L and Shi J. Dissociable effects of sleep deprivation on functional connectivity in the dorsal and ventral default mode networks. Sleep Med 2018: 50:137-44.
Dai C, Zhang Y, Cai X, Peng Z, Zhang L, Shao Y and Wang C. Effects of Sleep Deprivation on Working Memory: Change in Functional Connectivity Between the Dorsal Attention, Default Mode, and Fronto-Parietal Networks. Frontiers in human neuroscience 2020: 14:360.
Qi J, Li BZ, Zhang Y, Pan B, Gao YH, Zhan H, Liu Y, Shao YC and Zhang X. Altered insula-prefrontal functional connectivity correlates to decreased vigilant attention after total sleep deprivation. Sleep medicine 2021: 84:187-94.
Feng S, Yao H, Zheng S, Feng Z, Liu X, Liu R, Dong L, Cai Y, Jia H and Ning Y. Altered Functional Connectivity in Working Memory Network After Acute Sleep Deprivation. Neuroscience 2023: 535:158-67.
Stein H. Why Does the Neocortex Need the Cerebellum for Working Memory? The Journal of neuroscience : the official journal of the Society for Neuroscience 2021: 41:6368-70.
Thürling M, Hautzel H, Küper M, Stefanescu MR, Maderwald S, Ladd ME and Timmann D. Involvement of the cerebellar cortex and nuclei in verbal and visuospatial working memory: a 7 T fMRI study. Neuroimage 2012: 62:1537-50.
Won J, Callow DD, Purcell JJ and Smith JC. Differential associations of regional cerebellar volume with gait speed and working memory. Sci Rep 2022: 12:2355.
Canto CB, Onuki Y, Bruinsma B, van der Werf YD and De Zeeuw CI. The Sleeping Cerebellum. Trends Neurosci 2017: 40:309-23.
De Zeeuw CI and Canto CB. Sleep deprivation directly following eyeblink-conditioning impairs memory consolidation. Neurobiology of learning and memory 2020: 170:107165.
DelRosso LM and Hoque R. The cerebellum and sleep. Neurol Clin 2014: 32:893-900.
Dai XJ, Jiang J, Zhang Z, Nie X, Liu BX, Pei L, Gong H, Hu J, Lu G and Zhan Y. Plasticity and Susceptibility of Brain Morphometry Alterations to Insufficient Sleep. Front Psychiatry 2018: 9:266.
Liu X, Yan Z, Wang T, Yang X, Feng F, Fan L and Jiang J. Connectivity pattern differences bilaterally in the cerebellum posterior lobe in healthy subjects after normal sleep and sleep deprivation: a resting-state functional MRI study. Neuropsychiatr Dis Treat 2015: 11:1279-89.
Guo W, Mao X, Han D, Wang H, Zhang W, Zhang G, Zhang N, Nie B, Li H, Song Y, Wu Y and Chang L. Sleep deprivation aggravated amyloid β oligomers-induced damage to the cerebellum of rats: Evidence from magnetic resonance imaging. Aging brain 2023: 4:100091.
Ng HB, Kao KL, Chan YC, Chew E, Chuang KH and Chen SH. Modality specificity in the cerebro-cerebellar neurocircuitry during working memory. Behav Brain Res 2016: 305:164-73.
Sobczak-Edmans M, Lo YC, Hsu YC, Chen YJ, Kwok FY, Chuang KH, Tseng WI and Chen SHA. Cerebro-Cerebellar Pathways for Verbal Working Memory. Frontiers in human neuroscience 2018: 12:530.
Li Y, Yang L, Li L, Xie Y and Fang P. The resting-state cerebro-cerebellar function connectivity and associations with verbal working memory performance. Behav Brain Res 2022: 417:113586.
Faul F, Erdfelder E, Lang A-G and Buchner A. G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behavior research methods 2007: 39:175-91.
Feng S, Zheng S, Zou H, Dong L, Zhu H, Liu S, Wang D, Ning Y and Jia H. Altered functional connectivity of cerebellar networks in first-episode schizophrenia. Front Cell Neurosci 2022: 16:1024192.
Li L, Su YA, Wu YK, Castellanos FX, Li K, Li JT, Si TM and Yan CG. Eight-week antidepressant treatment reduces functional connectivity in first-episode drug-naïve patients with major depressive disorder. Hum Brain Mapp 2021: 42:2593-605.
Yan CG, Wang XD and Lu B. DPABISurf: data processing & analysis for brain imaging on surface. Sci Bull 2021: 66:2453-5.
Rolls ET, Huang CC, Lin CP, Feng J and Joliot M. Automated anatomical labelling atlas 3. Neuroimage 2020: 206:116189.
Cai Y, Mai Z, Li M, Zhou X and Ma N. Altered frontal connectivity after sleep deprivation predicts sustained attentional impairment: A resting-state functional magnetic resonance imaging study. Journal of sleep research 2021: 30:e13329.
Lei Y, Shao Y, Wang L, Zhai T, Zou F, Ye E, Jin X, Li W, Qi J and Yang Z. Large-Scale Brain Network Coupling Predicts Total Sleep Deprivation Effects on Cognitive Capacity. PLoS One 2015: 10:e0133959.
Feng P, Becker B, Feng T and Zheng Y. Alter spontaneous activity in amygdala and vmPFC during fear consolidation following 24 h sleep deprivation. Neuroimage 2018: 172:461-9.
Fastenrath M, Spalek K, Coynel D, Loos E, Milnik A, Egli T, Schicktanz N, Geissmann L, Roozendaal B, Papassotiropoulos A and de Quervain DJ. Human cerebellum and corticocerebellar connections involved in emotional memory enhancement. Proc Natl Acad Sci U S A 2022: 119:e2204900119.
Marvel CL, Morgan OP and Kronemer SI. How the motor system integrates with working memory. Neurosci Biobehav Rev 2019: 102:184-94.
Wang H, Yu K, Yang T, Zeng L, Li J, Dai C, Peng Z, Shao Y, Fu W and Qi J. Altered Functional Connectivity in the Resting State Neostriatum After Complete Sleep Deprivation: Impairment of Motor Control and Regulatory Network. Front Neurosci 2021: 15:665687.
Wang L, Wu H, Dai C, Peng Z, Song T, Xu L, Xu M, Shao Y, Li S and Fu W. Dynamic hippocampal functional connectivity responses to varying working memory loads following total sleep deprivation. Journal of sleep research 2023: 32:e13797.
Stoodley CJ and Schmahmann JD. Functional topography of the human cerebellum. Handbook of clinical neurology 2018: 154:59-70.
Stojanoski B, Benoit A, Van Den Berg N, Ray LB, Owen AM, Shahidi Zandi A, Quddus A, Comeau FJE and Fogel SM. Sustained vigilance is negatively affected by mild and acute sleep loss reflected by reduced capacity for decision making, motor preparation, and execution. Sleep 2019: 42.
Guell X, Gabrieli JDE and Schmahmann JD. Triple representation of language, working memory, social and emotion processing in the cerebellum: convergent evidence from task and seed-based resting-state fMRI analyses in a single large cohort. Neuroimage 2018: 172:437-49.
Kirschen MP, Chen SH and Desmond JE. Modality specific cerebro-cerebellar activations in verbal working memory: an fMRI study. Behav Neurol 2010: 23:51-63.
Ashida R, Cerminara NL, Edwards RJ, Apps R and Brooks JCW. Sensorimotor, language, and working memory representation within the human cerebellum. Hum Brain Mapp 2019: 40:4732-47.

Table 1 Results of N-back tasks (RW vs. SD)

	One-back task			Two-back task
	RW	SD	p value	RW	SD	p value
RT	526.36 ± 19.31	552.49 ± 15.46	0.014	708.56 ± 35.88	719.01 ± 31.32	0.690
ACC	0.90 (0.86-0.97)	0.92 (0.88-0.97)	0.889	0.87 (0.83-0.93)	0.81 ± 0.03	0.070

ACC accuracy, RT reaction time, RW rested wakefulness, SD sleep deprivation.

Table 2 Altered FC between the cerebellum and cerebrum after SD

	T value	p value
Right Lobule X of Cerebellum and Left Precentral gyrus	-3.778	0.0007
Right Lobule X of Cerebellum and Left Amygdala	-3.753	0.0008
Right Lobule X of Cerebellum and Left Ventral anterior of Thalamus	-3.848	0.0006
Right Lobule III of Cerebellum and Left Ventral anterior of Thalamus	-5.429	<0.0001
Right Lobule III of Cerebellum and Left Lateral posterior of Thalamus	-5.031	<0.0001
Right Lobule III of Cerebellum and Right Lateral posterior of Thalamus	-4.016	0.0004
Right Lobule III of Cerebellum and Left Intralaminar of Thalamus	-4.093	0.0003
Right Lobule III of Cerebellum and Left Reuniens of Thalamus	-3.754	0.0008
Left Lobule III Cerebellum and Left Ventral anterior of Thalamus	-4.164	0.0003
Left Lobule III Cerebellum and Left Lateral posterior of Thalamus	-4.396	0.0001

FC functional connectivity, SD sleep deprivation.

No competing interests reported.

Altered Cerebro-Cerebellar Functional Connectivity Associated with Working Memory Decline after Sleep Deprivation

Status:

Version 1

Abstract

Figures

Introduction

Methods

Results

Discussion

Declarations

References

Tables

Additional Declarations

Status:

Version 1