Maegen E Walker, Jonas F Vibell, Andrew D Dewald, Scott Sinnett
{"title":"Ageing and selective inhibition of irrelevant information in an attention-demanding rapid serial visual presentation task.","authors":"Maegen E Walker, Jonas F Vibell, Andrew D Dewald, Scott Sinnett","doi":"10.1177/23982128211073427","DOIUrl":"https://doi.org/10.1177/23982128211073427","url":null,"abstract":"<p><p>Attention involves both an ability to selectively focus on relevant information and simultaneously ignore irrelevant information (i.e. inhibitory control). Many factors impact inhibitory control such as individual differences, relative timing of stimuli presentation, distractor characteristics, and participant age. Previous research with young adults responding to an attention-demanding rapid serial visual presentations of pictures superimposed with task-irrelevant words evaluated the extent to which unattended information may be subject to inhibitory control. Surprise recognition tests following the rapid serial visual presentation task showed that recognition for unattended words presented with non-targets (i.e. non-aligned or 'NA' words) during the rapid serial visual presentation task were recognised at chance levels. However, when the unattended words were infrequently paired with the attended picture targets (i.e. target-aligned or 'TA' words), recognition rates were significantly below chance and significantly lower compared to NA words, suggesting selective inhibitory control for the previously unattended TA words. The current study adapted this paradigm to compare healthy younger and older adults' ability to engage in inhibitory control. In line with previous research, younger adults demonstrated selective inhibition with recognition rates for TA words significantly lower than NA words and chance, while NA words were recognised at chance levels. However, older adults showed no difference in recognition rates between word types (TA versus NA). Rather all items were recognised at rates significantly below chance suggesting inhibited recognition for all unattended words, regardless of when they were presented during the primary task. Finally, older adults recognised significantly fewer NA words compared to young adults. These findings suggest that older adults may experience a decline in their ability to selectively inhibit the processing of irrelevant information, while maintaining the capacity to exercise global inhibition over unattended lexical information.</p>","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/9e/db/10.1177_23982128211073427.PMC8793383.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39573414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ashley M Francis, Jenna N Bissonnette, Sarah E MacNeil, Candice E Crocker, Philip G Tibbo, Derek J Fisher
{"title":"Interaction of sex and cannabis in adult <i>in vivo</i> brain imaging studies: A systematic review.","authors":"Ashley M Francis, Jenna N Bissonnette, Sarah E MacNeil, Candice E Crocker, Philip G Tibbo, Derek J Fisher","doi":"10.1177/23982128211073431","DOIUrl":"10.1177/23982128211073431","url":null,"abstract":"<p><p>Cannabis has been shown to cause structural and functional neurocognitive changes in heavy users. Cannabis use initiation aligns with brain development trajectories; therefore, it is imperative that the potential neurological implications of cannabis use are understood. Males and females reach neurodevelopmental milestones at different rates making it necessary to consider biological sex in all cannabis and brain-based research. Through use of a systamatic review in accordance with PRISMA guidelines, we aimed to understand the interaction between biological sex and cannabis use on brain-based markers. In total, 18 articles containing a sex-based analysis of cannabis users were identified. While the majority of studies (<i>n</i> = 11) reported no sex by cannabis use interactions on brain-based markers, those that reported findings (<i>n</i> = 8) suggest females may be more susceptible to cannabis' neurotoxic effects. Unfortunately, a large portion of the literature was excluded due to no sex-based analysis. In addition, studies that reported no sex differences often contained a reduced number of females which may result in some studies being underpowered for sex-based analyses, making it difficult to draw firm conclusions. Suggestions to improve cannabis and sex-based reseach are proposed.</p>","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8793398/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39873088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jie Yeap, Chaitra Sathyaprakash, Jamie Toombs, Jane Tulloch, Cristina Scutariu, Jamie Rose, Karen Burr, Caitlin Davies, Marti Colom-Cadena, Siddharthan Chandran, Charles H Large, Matthew J M Rowan, Martin J Gunthorpe, Tara L Spires-Jones
{"title":"Reducing voltage-dependent potassium channel Kv3.4 levels ameliorates synapse loss in a mouse model of Alzheimer's disease.","authors":"Jie Yeap, Chaitra Sathyaprakash, Jamie Toombs, Jane Tulloch, Cristina Scutariu, Jamie Rose, Karen Burr, Caitlin Davies, Marti Colom-Cadena, Siddharthan Chandran, Charles H Large, Matthew J M Rowan, Martin J Gunthorpe, Tara L Spires-Jones","doi":"10.1177/23982128221086464","DOIUrl":"https://doi.org/10.1177/23982128221086464","url":null,"abstract":"<p><p>Synapse loss is associated with cognitive decline in Alzheimer's disease, and owing to their plastic nature, synapses are an ideal target for therapeutic intervention. Oligomeric amyloid beta around amyloid plaques is known to contribute to synapse loss in mouse models and is associated with synapse loss in human Alzheimer's disease brain tissue, but the mechanisms leading from Aβ to synapse loss remain unclear. Recent data suggest that the fast-activating and -inactivating voltage-gated potassium channel subtype 3.4 (Kv3.4) may play a role in Aβ-mediated neurotoxicity. Here, we tested whether this channel could also be involved in Aβ synaptotoxicity. Using adeno-associated virus and clustered regularly interspaced short palindromic repeats technology, we reduced Kv3.4 expression in neurons of the somatosensory cortex of APP/PS1 mice. These mice express human familial Alzheimer's disease-associated mutations in amyloid precursor protein and presenilin-1 and develop amyloid plaques and plaque-associated synapse loss similar to that observed in Alzheimer's disease brain. We observe that reducing Kv3.4 levels ameliorates dendritic spine loss and changes spine morphology compared to control virus. In support of translational relevance, Kv3.4 protein was observed in human Alzheimer's disease and control brain and is associated with synapses in human induced pluripotent stem cell-derived cortical neurons. We also noted morphological changes in induced pluripotent stem cell neurones challenged with human Alzheimer's disease-derived brain homogenate containing Aβ but, in this in vitro model, total mRNA levels of Kv3.4 were found to be reduced, perhaps as an early compensatory mechanism for Aβ-induced damage. Overall, our results suggest that approaches to reduce Kv3.4 expression and/or function in the Alzheimer's disease brain could be protective against Aβ-induced synaptic alterations.</p>","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8961358/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9415452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Silvia Pregnolato, H. Sabir, K. Luyt, Kira D. A. Rienecker, A. Isles, E. Chakkarapani
{"title":"Regulation of glutamate transport and neuroinflammation in a term newborn rat model of hypoxic–ischaemic brain injury","authors":"Silvia Pregnolato, H. Sabir, K. Luyt, Kira D. A. Rienecker, A. Isles, E. Chakkarapani","doi":"10.1177/23982128221097568","DOIUrl":"https://doi.org/10.1177/23982128221097568","url":null,"abstract":"In the newborn brain, moderate-severe hypoxia–ischaemia induces glutamate excitotoxicity and inflammation, possibly via dysregulation of candidate astrocytic glutamate transporter (Glt1) and pro-inflammatory cytokines (e.g. Tnfα, Il1β, Il6). Epigenetic mechanisms may mediate dysregulation. Hypotheses: (1) hypoxia–ischaemia dysregulates mRNA expression of these candidate genes; (2) expression changes in Glt1 are mediated by DNA methylation changes; and (3) methylation values in brain and blood are correlated. Seven-day-old rat pups (n = 42) were assigned to nine groups based on treatment (for each timepoint: naïve (n = 3), sham (n = 3), hypoxia–ischaemia (n = 8) and timepoint for tissue collection (6, 12 and 24 h post-hypoxia). Moderate hypoxic–ischemic brain injury was induced via ligation of the left common carotid artery followed by 100 min hypoxia (8% O2, 36°C). mRNA was quantified in cortex and hippocampus for the candidate genes, myelin (Mbp), astrocytic (Gfap) and neuronal (Map2) markers (qPCR). DNA methylation was measured for Glt1 in cortex and blood (bisulphite pyrosequencing). Hypoxia–ischaemia induced pro-inflammatory cytokine upregulation in both brain regions at 6 h. This was accompanied by gene expression changes potentially indicating onset of astrogliosis and myelin injury. There were no significant changes in expression or promoter DNA methylation of Glt1. This pilot study supports accumulating evidence that hypoxia–ischaemia causes neuroinflammation in the newborn brain and prioritises further expression and DNA methylation analyses focusing on this pathway. Epigenetic blood biomarkers may facilitate identification of high-risk newborns at birth, maximising chances of neuroprotective interventions.","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43262182","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jennifer G. Pearlstein, Sheri L. Johnson, James W. Madole, Kiana Modavi
{"title":"Emotion-related impulsivity: Testing a model of arousal effects on cognitive control","authors":"Jennifer G. Pearlstein, Sheri L. Johnson, James W. Madole, Kiana Modavi","doi":"10.1177/23982128221079572","DOIUrl":"https://doi.org/10.1177/23982128221079572","url":null,"abstract":"The trait-based tendency to respond rashly to emotions is robustly tied to many forms of psychopathology and poor behavioural outcomes, including aggression and suicidality. Researchers have found associations between response inhibition and emotion-related impulsivity; however, effect sizes are often small. Because emotion-related impulsivity emerges in the context of heightened positive and negative emotions, arousal is a candidate trigger of impulsivity. The goals of the present study were to (1) replicate the association between emotion-related impulsivity and response inhibition, and (2) test whether emotion-related impulsivity is associated with arousal-induced decays in response inhibition performance. Participants (N = 55) completed a self-report measure of emotion-related impulsivity, and then completed a computer-based response inhibition task (the antisaccade task, in which participants must make a rapid saccadic eye movement away from a cue rather than toward it) before and after a well-validated stress induction (the Trier Social Stress Test). Psychophysiological indices of arousal were measured throughout the session. Findings provide partial support for the association between emotion-related impulsivity and pre-stress response inhibition. Contrary to hypotheses, emotion-related impulsivity did not interact with arousal to predict post-stress response inhibition performance after controlling for pre-stress response inhibition performance. Future research is needed to consider clinical samples and to assess whether emotion-related impulsivity is related to deficits in other facets of cognitive control and decision-making.","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42334017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Martin Viktorov, Matthew P. Wilkinson, Victoria C. E. Elston, Medi Stone, E. Robinson
{"title":"A systematic review of studies investigating the acute effects of N-methyl- D -aspartate receptor antagonists on behavioural despair in normal animals suggests poor predictive validity","authors":"Martin Viktorov, Matthew P. Wilkinson, Victoria C. E. Elston, Medi Stone, E. Robinson","doi":"10.1177/23982128221081645","DOIUrl":"https://doi.org/10.1177/23982128221081645","url":null,"abstract":"The ability of the N-methyl- D -aspartate receptor antagonist ketamine to induce a rapid and sustained antidepressant effect has led to a surge in pre-clinical studies investigating underlying mechanisms and seeking novel treatments. Animal models are key to this research as they can provide a behavioural readout linking underlying mechanisms to clinical benefits. However, quantifying depression-related behaviours in rodents represents a major challenge with the validity of traditional methods such as models of behavioural despair (forced swim test and tail suspension test) a topic of debate. While there is good evidence to support the value of using these behavioural readouts to study the effects of stress, these approaches have largely failed to detect reliable phenotypic effects in other disease models. In this systematic review, we identified publications which had tested N-methyl- D -aspartate receptor antagonists in normal animals using either the forced swim test or tail suspension test. We compared findings for different doses and time points and also drugs with different clinical profiles to investigate how well the outcomes in the rodent model predicted their effects in the clinic. Despite clear evidence that N-methyl- D -aspartate receptor antagonists reduce immobility time and hence exhibit an antidepressant profile in these tasks, we found similar effects with both clinically effective drugs as well as those which have failed to show efficacy in clinical trials. These findings suggest that behavioural despair tests in normal animals do not provide a good method to predict clinical efficacy of N-methyl- D -aspartate receptor antagonists.","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48388728","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Megan G. Jackson, Laura J Brennan, E. Henderson, E. Robinson
{"title":"Modelling falls in Parkinson’s disease and normal ageing in mice using a complex motor task","authors":"Megan G. Jackson, Laura J Brennan, E. Henderson, E. Robinson","doi":"10.1177/23982128221088794","DOIUrl":"https://doi.org/10.1177/23982128221088794","url":null,"abstract":"Falls resulting from multifactorial deficits are common in both normal ageing and Parkinson’s disease. Resultant injuries can lead to increased hospitalisation and excess mortality. As the disease progresses, gait and balance deficits are relatively refractory to dopaminergic treatments suggesting another system is involved. Attentional impairment is a significant risk factor for falls, and disruption to both the cortical cholinergic system and striatal dopaminergic system increases falls in rats undergoing a complex motor task with high attentional load. However, it is unclear whether this translates to mice and whether normal ageing induces similar deficits. In this study, we use a complex motor task to test the effects of acute dopaminergic and cholinergic antagonism using alpha-flupentixol and scopolamine, respectively, in mice. We also test the effects of normal ageing on complex motor performance and whether these changes are sensitive to a clinical dose of the non-steroidal anti-inflammatory Rimadyl. Consistent with previous work, we show that cholinergic but not dopaminergic antagonism impaired task performance. However, a combined approach did not potentiate the deficit beyond observed with cholinergic antagonism alone. We also show that task performance is impaired in aged mice relative to younger controls, and that Rimadyl reduces number of foot slips in an age-specific manner. Overall, these data support prior work showing the importance of the cholinergic system in falls. The studies in aged mice found age-related impairments and a role for inflammation but did not find evidence of an interaction with attentional load, although only one manipulation was tested.","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44235880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Evans, Kayle S. Sawyer, Sarah A. Levy, Jessica P. Conklin, EmilyKate McDonough, D. Gansler
{"title":"Factors in the neurodevelopment of negative urgency: Findings from a community-dwelling sample","authors":"C. Evans, Kayle S. Sawyer, Sarah A. Levy, Jessica P. Conklin, EmilyKate McDonough, D. Gansler","doi":"10.1177/23982128221079548","DOIUrl":"https://doi.org/10.1177/23982128221079548","url":null,"abstract":"This study investigated neuroanatomic, genetic, cognitive, sociodemographic and emotional underpinnings of the Negative Urgency subscale of the Urgency, Premeditation, Perseverance, Sensation-Seeking and Positive Urgency Impulsive Behavior Scale in a healthy developmental sample. The goal of the investigation is to contribute to the harmonisation of behavioural, brain and neurogenetic aspects of behavioural self-control. Three domains – (1) Demographic, developmental, psychiatric and cognitive ability; (2) Regional brain volumes (neurobiological); and (3) Genetic variability (single nucleotide polymorphisms) – were examined, and models with relevant predictor variables were selected. Least absolute shrinkage and selection operator and best subset regressions were used to identify sparse models predicting negative urgency scores, which revealed that variables related to emotional regulation and right cingulate volume, as well as single nucleotide polymorphisms in CADM2 and SLC6A4, were associated with negative urgency. Our results contribute to the construct and criterion validity of negative urgency and support the hypothesis that negative urgency is a result of a complex array of influences across domains whose integration furthers developmental psychopathology research.","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46836327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kenneth J D Allen, Sheri L Johnson, Taylor A Burke, M McLean Sammon, Christina Wu, Max A Kramer, Jinhan Wu, Heather T Schatten, Michael F Armey, Jill M Hooley
{"title":"Validation of an emotional stop-signal task to probe individual differences in emotional response inhibition: Relationships with positive and negative urgency.","authors":"Kenneth J D Allen, Sheri L Johnson, Taylor A Burke, M McLean Sammon, Christina Wu, Max A Kramer, Jinhan Wu, Heather T Schatten, Michael F Armey, Jill M Hooley","doi":"10.1177/23982128211058269","DOIUrl":"10.1177/23982128211058269","url":null,"abstract":"<p><p>Performance on an emotional stop-signal task designed to assess emotional response inhibition has been associated with Negative Urgency and psychopathology, particularly self-injurious behaviors. Indeed, difficulty inhibiting prepotent negative responses to aversive stimuli on the emotional stop-signal task (i.e. poor <i>negative</i> emotional response inhibition) partially explains the association between Negative Urgency and non-suicidal self-injury. Here, we combine existing data sets from clinical (hospitalised psychiatric inpatients) and non-clinical (community/student participants) samples aged 18-65 years (<i>N</i> = 450) to examine the psychometric properties of this behavioural task and evaluate hypotheses that emotional stop-signal task metrics relate to distinct impulsive traits among participants who also completed the UPPS-P (<i>n</i> = 223). We specifically predicted associations between worse <i>negative</i> emotional response inhibition (i.e. commission errors during stop-signal trials representing negative reactions to unpleasant images) and Negative Urgency, whereas commission errors to positive stimuli - reflecting worse <i>positive</i> emotional response inhibition - would relate to Positive Urgency. Results support the emotional stop-signal task's convergent and discriminant validity: as hypothesised, poor negative emotional response inhibition was specifically associated with Negative Urgency and no other impulsive traits on the UPPS-P. However, we did not find the hypothesised association between positive emotional response inhibition and Positive Urgency. Correlations between emotional stop-signal task performance and self-report measures were the modest, similar to other behavioural tasks. Participants who completed the emotional stop-signal task twice (<i>n</i> = 61) additionally provide preliminary evidence for test-retest reliability. Together, findings suggest adequate reliability and validity of the emotional stop-signal task to derive candidate behavioural markers of neurocognitive functioning associated with Negative Urgency and psychopathology.</p>","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ftp.ncbi.nlm.nih.gov/pub/pmc/oa_pdf/2e/bb/10.1177_23982128211058269.PMC8619735.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39941546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vasileia Kotoula, Toby Webster, James Stone, Mitul A Mehta
{"title":"Resting-state connectivity studies as a marker of the acute and delayed effects of subanaesthetic ketamine administration in healthy and depressed individuals: A systematic review.","authors":"Vasileia Kotoula, Toby Webster, James Stone, Mitul A Mehta","doi":"10.1177/23982128211055426","DOIUrl":"https://doi.org/10.1177/23982128211055426","url":null,"abstract":"<p><p>Acute ketamine administration has been widely used in neuroimaging research to mimic psychosis-like symptoms. Within the last two decades, ketamine has also emerged as a potent, fast-acting antidepressant. The delayed effects of the drug, observed 2-48 h after a single infusion, are associated with marked improvements in depressive symptoms. At the systems' level, several studies have investigated the acute ketamine effects on brain activity and connectivity; however, several questions remain unanswered around the brain changes that accompany the drug's antidepressant effects and how these changes relate to the brain areas that appear with altered function and connectivity in depression. This review aims to address some of these questions by focusing on resting-state brain connectivity. We summarise the studies that have examined connectivity changes in treatment-naïve, depressed individuals and those studies that have looked at the acute and delayed effects of ketamine in healthy and depressed volunteers. We conclude that brain areas that are important for emotional regulation and reward processing appear with altered connectivity in depression whereas the default mode network presents with increased connectivity in depressed individuals compared to healthy controls. This finding, however, is not as prominent as the literature often assumes. Acute ketamine administration causes an increase in brain connectivity in healthy volunteers. The delayed effects of ketamine on brain connectivity vary in direction and appear to be consistent with the drug normalising the changes observed in depression. The limited number of studies however, as well as the different approaches for resting-state connectivity analysis make it very difficult to draw firm conclusions and highlight the importance of data sharing and larger future studies.</p>","PeriodicalId":72444,"journal":{"name":"Brain and neuroscience advances","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8597064/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39645404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}