Background:Sleep deprivation(SD)can potentially lead to deficits in many cognitive capacities,suggesting that sleep pressure represented a basic physiological constraint of brain function.However,the neural mechanism ...Background:Sleep deprivation(SD)can potentially lead to deficits in many cognitive capacities,suggesting that sleep pressure represented a basic physiological constraint of brain function.However,the neural mechanism underlying the decline awareness and cognition induced by SD is far from clear.Methods:Thirty-seven healthy male adults were recruited in this within-subjects,repeat-measure,counterbalanced study.These individuals were both examined during a state of rested wakefulness(RW)state and after 36 hours of total SD.Using functional connectivity magnetic resonance imaging(fcMRI),we investigated the specifi c effect of SD on static functional connectivity density,sparse representation of resting-state fMRI signal,and dynamic connectivity pattern.Results:Our analysis based on fcMRI revealed that multiple functional networks involved in memory,emotion,attention,and vigilance processing were impaired by SD.Of particular interest,the thalamus was observed to contribute to multiple functional networks in which differentiated response patterns were exhibited.We also detect robust changes in the temporal properties of specifi c connectivity states,such as the occurrence frequencies,dwell times and transition probabilities that were likely associated with the vigilance loss induced by SD.These changes led to differentiation of these states with the RW-dominant states characterized by anti-correlation between the default mode network and other cortices and the SD-dominant states marked by significantly decreased thalamocortical connectivity.Conclusion:These fi ndings suggest specifi c patterns of the large-scale functional brain network changes after SD,which are important for understanding of the impacts of SD on brain function and developing effective intervention strategy against SD.展开更多
Objective:Addiction is a reward deficit and stress surfeit disorder.By using resting-state functional connectivity MRI(rs-fcMRI),the aim of this study is to investigate the pattern of aberrant brain networks in heroin...Objective:Addiction is a reward deficit and stress surfeit disorder.By using resting-state functional connectivity MRI(rs-fcMRI),the aim of this study is to investigate the pattern of aberrant brain networks in heroin addiction,and whether addiction-related brain abnormalities would be persistent or recovered after long periods of abstinence.Methods:Rs-fcMRI analysis was performed on groups of recently abstinent(no more than 3 months)heroin-dependent(HD)subjects,long-term abstinent(more than 3 years)HD subjects,and non-addicted control(CN)subjects.The left and right nucleus accumbens(NAc)were defi ned as the seed regions of interest(ROIs),a brain region implicated in relapse-related processes,including craving and reactivity to stress following acute and protracted withdrawal from heroin.For each subject,correlation maps were created by calculating Pearson’s correlation coeffi cients between the time series of the seed ROIs and that of each voxel in the brain.These correlation maps were converted to Z-value maps using Fisher’s r-to-z transformation.Two-sample t-test was performed between different groups,to identify possible addiction-related NAc functional connectivity changes.The relationship between the duration of abstinence and the altered NAc functional connectivity in the heroin group was also examined.Results:Compared to the CN group,the recently abstinent HD group showed signifi cantly increased functional connectivity between the NAc and the reward network(caudate,amygdala,thalamus and ventral medial prefrontal cortex),whereas decreased functional connectivity between the NAc and the executive control network(frontal-parietal regions).The long-term abstinent HD group also showed imbalanced functional link between the reward and executive control networks.However,with longer abstinence time,the strength of some NAc functional connectivity gradually restored to near-normal levels.Conclusion:Our results suggest that the imbalanced functional link between large-scale brain networks could serve as system-level neural underpinnings of persistent drug addiction and potential for relapse,which can at least partly be recovered after long periods of abstinence.展开更多
文摘Background:Sleep deprivation(SD)can potentially lead to deficits in many cognitive capacities,suggesting that sleep pressure represented a basic physiological constraint of brain function.However,the neural mechanism underlying the decline awareness and cognition induced by SD is far from clear.Methods:Thirty-seven healthy male adults were recruited in this within-subjects,repeat-measure,counterbalanced study.These individuals were both examined during a state of rested wakefulness(RW)state and after 36 hours of total SD.Using functional connectivity magnetic resonance imaging(fcMRI),we investigated the specifi c effect of SD on static functional connectivity density,sparse representation of resting-state fMRI signal,and dynamic connectivity pattern.Results:Our analysis based on fcMRI revealed that multiple functional networks involved in memory,emotion,attention,and vigilance processing were impaired by SD.Of particular interest,the thalamus was observed to contribute to multiple functional networks in which differentiated response patterns were exhibited.We also detect robust changes in the temporal properties of specifi c connectivity states,such as the occurrence frequencies,dwell times and transition probabilities that were likely associated with the vigilance loss induced by SD.These changes led to differentiation of these states with the RW-dominant states characterized by anti-correlation between the default mode network and other cortices and the SD-dominant states marked by significantly decreased thalamocortical connectivity.Conclusion:These fi ndings suggest specifi c patterns of the large-scale functional brain network changes after SD,which are important for understanding of the impacts of SD on brain function and developing effective intervention strategy against SD.
文摘Objective:Addiction is a reward deficit and stress surfeit disorder.By using resting-state functional connectivity MRI(rs-fcMRI),the aim of this study is to investigate the pattern of aberrant brain networks in heroin addiction,and whether addiction-related brain abnormalities would be persistent or recovered after long periods of abstinence.Methods:Rs-fcMRI analysis was performed on groups of recently abstinent(no more than 3 months)heroin-dependent(HD)subjects,long-term abstinent(more than 3 years)HD subjects,and non-addicted control(CN)subjects.The left and right nucleus accumbens(NAc)were defi ned as the seed regions of interest(ROIs),a brain region implicated in relapse-related processes,including craving and reactivity to stress following acute and protracted withdrawal from heroin.For each subject,correlation maps were created by calculating Pearson’s correlation coeffi cients between the time series of the seed ROIs and that of each voxel in the brain.These correlation maps were converted to Z-value maps using Fisher’s r-to-z transformation.Two-sample t-test was performed between different groups,to identify possible addiction-related NAc functional connectivity changes.The relationship between the duration of abstinence and the altered NAc functional connectivity in the heroin group was also examined.Results:Compared to the CN group,the recently abstinent HD group showed signifi cantly increased functional connectivity between the NAc and the reward network(caudate,amygdala,thalamus and ventral medial prefrontal cortex),whereas decreased functional connectivity between the NAc and the executive control network(frontal-parietal regions).The long-term abstinent HD group also showed imbalanced functional link between the reward and executive control networks.However,with longer abstinence time,the strength of some NAc functional connectivity gradually restored to near-normal levels.Conclusion:Our results suggest that the imbalanced functional link between large-scale brain networks could serve as system-level neural underpinnings of persistent drug addiction and potential for relapse,which can at least partly be recovered after long periods of abstinence.
