Biology subjects

Bendova, Z.

Publications and source records attributed to Bendova, Z..

3 recordsLinked to original sources

bioRxiv2025

Bright Light Exposure Reduces Negative Affect and Modulates EEG Activity in Sleep-Deprived and Well-Rested Adolescents

This study investigated whether a single morning session of bright light exposure modulates alertness, cognition, mood, and EEG activity in well-rested and partially sleep-deprived adolescents. Forty-seven subjects (15 - 21 years) were assigned to a well-rested (8 h sleep; 9 men, 15 women) or a sleep-deprived group (4 h sleep; 11 men, 12 women). All underwent 30 minutes of morning bright light exposure, with EEG, cognitive testing, and ratings of sleepiness and affect conducted pre- and post-intervention. Behavioral and electrophysiological changes were compared within and between groups. Associations between changes in EEG activity and behavioral outcomes were explored using correlation analyses. Bright light significantly reduced negative affect and improved Digit Span Forward task performance. No changes were observed in positive affect, subjective sleepiness, or Digit Span Backward scores. EEG analysis revealed decreased delta activity in the anterior cingulate cortex and increased beta activity in the right insula and fronto-parietal regions. Behavioral and EEG effects were similar across groups; however, only in the sleep-deprived group changes in beta activity significantly correlated with reduced negative affect. These results suggest that bright light may acutely enhance emotional state, cognitive performance, and cortical arousal in adolescents. The link between beta activity and affective improvement under sleep deprivation suggests a potential mechanism by which light supports emotional regulation.

neuroscience↗

bioRxiv2024

Effects of serotonergic psychedelics on synaptogenesis and immediate early genes expression - comparison with ketamine, fluoxetine and lithium

BackgroundRecent evidence suggests that psychedelics are able to induce rapid and long-lasting antidepressant effects. The generally acknowledged explanation for these traits is the phenomenon of neuroplasticity, although exact underlying molecular mechanisms remain unclear. AimsThis study investigates selected neuroplastic effects of psilocin, lysergic acid diethylamide (LSD) and N,N-dimethyltryptamine (DMT) in direct comparison with ketamine, fluoxetine and lithium after acute (1 h) and/or prolonged (24 h) treatment in vitro. MethodsRat primary cortical cultures were treated with 10 {micro}M psilocin, 1 {micro}M lysergic acid diethylamide (LSD), 90 {micro}M N, N-dimethyltryptamine (DMT), 1 {micro}M ketamine, 10 {micro}M fluoxetine and 5 mM lithium. Analysis of synaptic puncta was performed; puncta of presynaptic marker synapsin I/II, postsynaptic density protein 95 (PSD-95), and their co-localization (established synapse) were assessed 24 h after drug treatment. Next, expressions of immediate early genes (IEGs) encoding activity-regulated cytoskeleton-associated protein (Arc), early growth response 1 (Egr1), and neuronal PAS (Per-ArntSim) domain protein 4 (Npas4) were analysed 1 and 24 h after drug treatments. ResultsPsilocin increased synaptic puncta count and induced Arc expression. The effect to promote synaptogenesis was comparable to ketamine and lithium; ketamine additionally increased PSD-95 puncta count. LSD and DMT didnt induce any significant effect. Interestingly, fluoxetine had no effect on synaptic puncta count, but upregulated Egr1 and Npas4. ConclusionsPsilocin demonstrated a significant neuroplastic effect comparable to that of ketamine and lithium, adding another piece of evidence to its profile as a promising therapeutic agent.

neuroscience↗

bioRxiv2018

The day/night difference in the circadian clock’s response to acute lipopolysaccharide and the rhythmic Stat3 expression in the rat suprachiasmatic nucleus

The circadian clock in the suprachiasmatic nucleus (SCN) regulates daily rhythms in physiology and behaviour and is an important part of the mammalian homeostatic system. Previously, we have shown that systemic inflammatory stimulation with lipopolysaccharide (LPS) induced the daytime-dependent phosphorylation of STAT3 in the SCN. Here, we demonstrate the LPS-induced Stat3 mRNA expression in the SCN and show also the circadian rhythm in Stat3 expression in the SCN, with high levels during the day. Moreover, we examined the effects of LPS (1mg/kg), applied either during the day or the night, on the rhythm in locomotor activity of male Wistar rats. We observed that recovery of normal locomotor activity patterns took longer when the animals were injected during the night. The clock genes Per1, Per2 and Nr1d1, and phosphorylation of kinases ERK1/2 and GSK3{beta} are sensitive to external cues and function as the molecular entry for external signals into the circadian clockwork. We also studied the immediate changes in these clock genes expressions and the phosphorylation of ERK1/2 and GSK3{beta} in the suprachiasmatic nucleus in response to daytime or night-time inflammatory stimulation. We revealed mild and transient changes with respect to the controls. Our data stress the role of STAT3 in the circadian clock response to the LPS and provide further evidence of the interaction between the circadian clock and immune system.

neuroscience↗