Biology subjects

Fedota, J. R.

Publications and source records attributed to Fedota, J. R..

2 recordsLinked to original sources

bioRxiv2021

Not all smokers are alike: The hidden cost of sustained attention during nicotine abstinence

BackgroundNicotine Withdrawal Syndrome (NWS)-associated cognitive deficits are heterogeneous, suggesting underlying endophenotypic subgroups. We identified smoker subgroups based on response accuracy during a cognitively demanding Parametric Flanker Task (PFT) and characterized their distinct neuroimaging endophenotypes using a nicotine state manipulation (sated, abstinent). MethodsForty-five smokers completed the 25-min PFT in two fMRI sessions (nicotine sated, abstinent). Task-evoked NWS-associated errors of omission (EOm), brain activity, underlying functional connectivity (FC), and brain-behavior correlations between subgroups were assessed. ResultsBased on their response accuracy in the high demand PFT condition, smokers split into high (HTP, n=21) and low task performer (LTP, n=24) subgroups. Behaviorally, HTPs showed greater response accuracy independent of nicotine state and greater vulnerability to abstinence-induced EOm. HTPs showed greater BOLD responses in attentional control brain regions for the [correct responses (-) errors of commission] PFT contrast across states. A whole-brain FC analysis with these subgroup-derived regions as seeds revealed two circuits: L Precentral : R Insula and L Insula : R Occipital, with abstinence-induced FC strength increases only in HTPs. Finally, abstinence-induced brain (FC) and behavior (EOm) differences were positively correlated for HTPs in a L Precentral : R Orbitofrontal cortical circuit. ConclusionWe used a cognitive stressor (PFT) to fractionate smokers into two subgroups (HTP/LTP). Only the HTPs demonstrated sustained attention deficits during nicotine abstinence, a stressor in dependent smokers. Unpacking underlying smoker heterogeneity with this dual stressor approach revealed distinct smoker subgroups with differential attention deficit responses to withdrawal that could be novel targets for therapeutic interventions to improve cessation outcomes.

neuroscience↗

bioRxiv2020

Time varying connectivity across the brain changes as a function of nicotine abstinence state

BackgroundThe Nicotine Withdrawal Syndrome (NWS) includes affective and cognitive disruptions whose incidence and severity vary across time during acute abstinence. However, most network-level neuroimaging employs static measures of resting state functional connectivity (rsFC), assuming time-invariance, and unable to capture dynamic brain-behavior relationships. Recent advances in rsFC signal processing allow characterization of "time varying connectivity" (TVC), which characterizes network communication between sub-networks that reconfigure over the course of data collection. As such, TVC may more fully describe network dysfunction related to the NWS. MethodsTo isolate alterations in the frequency and diversity of communication across network boundaries as a function of acute nicotine abstinence we scanned cigarette smokers in the nicotine sated and abstinent states and applied a previously-validated method to characterize TVC at a network and nodal level within the brain. ResultsDuring abstinence, we found brain wide decreases in the frequency of interactions between network nodes in different modular communities (i.e. temporal flexibility; TF). In addition, within a subset of the networks examined the variability of these interactions across community boundaries (i.e. spatiotemporal diversity; STD) also decreased. Finally, within two of these networks the decrease in STD was significantly related to NWS clinical symptoms. ConclusionsEmploying multiple measures of TVC in a within subjects design, we characterized a novel set of changes in network communication and link these changes to specific behavioral symptoms of the NWS. These reductions in TVC provide a meso-scale network description of the relative inflexibility of specific large-scale brain networks as a result of acute abstinence.

animal behavior and cognition↗