Search bioRxiv⌕ Search

Biology subjects

Junghanns, K.

Publications and source records attributed to Junghanns, K..

4 recordsLinked to original sources

Interleukin-6 responses to acute stress are not altered in alcohol use disorder despite elevated baseline inflammation

Acute stress activates the immune system, leading to the release of pro-inflammatory cytokines, such as interleukin-6 (IL-6). Chronic alcohol consumption alters the physiological stress systems and is associated with increased chronic inflammation. However, it remains unclear how IL-6 responds to acute stress in individuals with alcohol use disorder (AUD). Forty patients with AUD during early abstinence and 37 healthy controls (HC) completed two study visits. On one day, an acute stress induction task was performed, and on the other, a non-stressful control task, with the order of tasks being balanced. Plasma IL-6 and C-reactive protein (CRP) were measured as inflammatory markers at baseline and changes in IL-6 were assessed 90 minutes after the experimental manipulation. Patients with AUD showed significantly elevated baseline IL-6 and CRP compared to HC and the levels correlated positively with the amount of consumed alcohol in patients. IL-6 responses to the stress intervention did not differ between groups. Increases in IL-6 were observed on stress and control days and were larger when samples were collected via an indwelling catheter than with a butterfly needle. These findings suggest that IL-6 responses to acute stress do not differ between AUD and HC, despite increased baseline inflammation. Furthermore, the results indicate that blood collection methods can influence IL-6 measurements and highlight the importance of methodological considerations.

immunology↗

No neurobehavioral evidence for reduced motivational potential of social rewards in alcohol use disorder

BackgroundThe mesolimbic dopamine system plays a central role in motivating behavior. In alcohol use disorder (AUD), this system is thought to be dysfunctional, leading to hyperreactivity to alcohol-related cues. In contrast, evidence on how individuals with AUD respond to alcohol-unrelated reward cues is inconclusive, and the motivation for social rewards has not yet been investigated. MethodsTo address this gap, 36 individuals with AUD and 34 healthy controls performed an incentive delay task to assess social reward anticipation with a monetary and a non-reward control condition while undergoing functional magnetic resonance imaging. The ventral striatum was defined as region of interest because of its central role in neuronal circuits for motivation. ResultsNeither behavioral nor neuroimaging data provided any evidence of reduced motivation for social or monetary rewards in AUD. Exploratory whole-brain analyses only revealed stronger activation in the occipital/cuneal cortex in individuals with AUD than in healthy controls across all trials. ConclusionTogether, these results suggest that sensitivity to social reward cues is not fundamentally impaired in AUD. Furthermore, they imply that motivational changes related to the substance do not generally alter the reward potential of alcohol-unrelated domains in AUD, opening perspectives for social-behavioral treatments for this disorder.

neuroscience↗

Sleep to remember, sleep to protect: increased sleep spindle and theta activity predict fewer intrusive memories after analogue trauma

Recent evidence shows a strong correlative link between sleep disturbances and intrusive memories after traumatic events, presumably due to insufficient (nocturnal) memory integration. However, the underlying mechanisms of this link and the role of specific neural activities during sleep are poorly understood so far. Here, we investigated how the intra-individual affective response to an experimental trauma predicts changes in oscillatory activity during subsequent sleep and how these changes predict the processing of the experimental trauma. In a randomized within-subject comparison, twenty-two female, healthy participants (23.14 {+/-} 2.46 years) watched a well-validated film clip including "traumatic" contents and a neutral film clip before bedtime on two separate nights. Heart rate was recorded during the film clips and nocturnal brain activity was recorded using 64-channel high-density EEG during subsequent nights. Intrusive memories were assessed via a seven-days diary and negative affect was assessed using laboratory trauma film reminders one week after the trauma film. An increased intra-individual heart rate during the trauma film predicted higher intra-individual sleep spindle amplitude the following night. Increased theta activity (4.25 - 8 Hz) during rapid eye movement (REM) sleep after the trauma film predicted fewer trauma film related intrusive memories and negative affect. Likewise, an increase in sleep spindles after the trauma film predicted fewer trauma film related intrusive memories. Our findings suggest that an experience-dependent up-regulation of these nocturnal oscillatory activity patterns, which are known to be involved in adaptive memory consolidation processes, serves as a protective factor against trauma-related intrusive memory development. Particularly, increased theta activity during REM sleep and sleep spindle activity seem to be of importance here.

neuroscience↗

Reactivating a relaxation exercise during sleep to influence cortical hyperarousal in people with frequent nightmares - a randomized crossover trial

Study ObjectivesHigh-frequency EEG activity during sleep (cortical hyperarousal), is a transdiagnostic feature across psychiatric disorders, including nightmare disorder. It is discussed as a target of intervention; however, specific treatment options are yet unavailable. We tested whether exposure to relaxation-associated odor cues during sleep would reduce cortical hyperarousal, i.e. beta (16.25 - 31 Hz), gamma (31.25 - 45 Hz), spindle activity and nightmare occurrence in participants with frequent nightmares. MethodsTwenty-five (21 female, mean age (SD) = 24.94(5.01)) participants, recruited from undergraduate students at University of Luebeck, with [≥]1 nightmare / week received a deep breathing relaxation intervention for one week coupled with an odor. On two subsequent nights in the sleep laboratory, the associated odor (A), or control odor (B) were presented in randomized order in a crossover design with randomization at baseline; participants were blinded to intervention. ResultsN = 11 participants were allocated to AB and n = 14 to BA sequence. Exposure to relaxation-associated odor cues during sleep did not affect beta or gamma activity while spindle count and density were significantly reduced. Reduction in spindle count during reactivation nights correlated with reduced subjective wake-after-sleep-onset. There was no additional impact on nightmare symptoms. There were no adverse events or side effects. ConclusionsThe reactivation of relaxation-associated states with odor cues during sleep may be associated with changes in spectral activity, specifically spindle activity. Future studies should implement multiple nights of reactivation and include different patient groups with cortical hyperarousal to test the transdiagnostic potential of this new intervention.

neuroscience↗