Biology subjects

Akbari, R.

Publications and source records attributed to Akbari, R..

3 recordsLinked to original sources

bioRxiv2025

The Gut-Brain Axis Shapes Cognitive-Emotional Processing: Evidence for Attentional Avoidance of Bloating Cues in IBS

BackgroundIrritable bowel syndrome (IBS) is a functional gastrointestinal disorder characterized by significant gut-brain interactions and various symptoms such as abdominal pain, bloating, and altered bowel habits. Cognitive deficits in IBS have been linked to attentional biases, particularly towards somatic and symptom-related cues. Despite increasing interest in understanding these cognitive processes, the specific patterns of attentional biases and their relationship with anxiety in IBS remain inadequately explored. MethodThis study employed a dot-probe task to compare attentional biases toward somatic (bloating, pain) and social threat cues (angry/disgusted faces) in 15 patients with IBS, 15 individuals with high anxiety (HA), and 15 healthy controls (HC). Participants completed two tasks (Body/Face) with 500 ms stimulus exposure. Attentional bias indices (RT incongruent - RT congruent) were analyzed using mixed-design ANOVAs, controlling for anxiety (STAI) and IBS symptom severity (IBS-SSS). ResultsPatients with IBS exhibited significant avoidance of bloating-related stimuli compared to HC (p =.013), but not pain-related cues. Anxiety modulated attentional processing in IBS (p =.015) and HC (p =.013). HA showed no significant biases. IBS patients demonstrated slower overall reaction times than HC (p=.024), suggesting cognitive load. A positive IBS severity-anxiety correlation was observed in IBS (r = 0.574, p =.020). ConclusionsThe findings demonstrate that IBS is associated with selective avoidance of bloating-related stimuli, driven by a maladaptive interplay between hyper-precise symptom expectations and interoceptive noise--a mechanism distinct from anxiety-related attentional patterns. While anxiety amplifies this avoidance, it does not independently account for the cognitive profile of IBS. These results underscore the gut-brain axis role in shaping cognitive-emotional processing.

neuroscience↗

bioRxiv2025

Attention in Irritable Bowel Syndrome: A Systematic Review of Affected Domains and Brain-Gut Axis Interactions

BackgroundIrritable Bowel Syndrome (IBS) is a prevalent functional gastrointestinal disorder characterized by abdominal pain and altered bowel habits, significantly impacting patients quality of life. Recent research suggests that attention may be affected in individuals with IBS, potentially influencing symptom perception and emotional distress. ObjectiveThis systematic review aims to investigate the relationship between attention and IBS, focusing on the affected domains of attention and the interactions within the brain-gut axis. MethodsA comprehensive literature search was conducted across multiple databases, including MEDLINE/PubMed, PsychINFO, and Scopus, from January 1990 to December 2024. Studies were included if they assessed attention in adult IBS patients and employed valid measurement tools. A total of 24 studies were selected for analysis, encompassing various methodologies, including neuroimaging and behavioral assessments. ResultsThe findings indicate that IBS patients exhibit significant attentional biases, particularly towards gastrointestinal-related stimuli, reflecting heightened sensitivity and hypervigilance. Specific domains of attention, including selective attention, sustained attention, and pre-attentional processing, were identified as being affected. The review highlights the role of psychological factors, such as anxiety and depression, in modulating attention in IBS. Neuroimaging studies revealed altered brain activation patterns in regions associated with attention and emotional processing, suggesting a complex interplay between cognitive function and the brain-gut axis. ConclusionThis systematic review underscores the multifaceted nature of attention in IBS, revealing specific attentional deficits and biases that may contribute to symptom exacerbation and emotional distress. The findings emphasize the need for further research to explore the underlying mechanisms and potential therapeutic interventions aimed at addressing attention in IBS patients.

neuroscience↗

bioRxiv2021

Decreased overall neuronal activity in a rodent model of impaired consciousness during absence seizures

Absence seizures are characterized by a brief behavioural impairment including apparent loss of consciousness. Neuronal mechanisms determining the behavioural impairment of absence seizures remain unknown, and their elucidation might highlight therapeutic options for reducing seizure severity. However, recent studies have questioned the similarity of animal spike-wave-discharges (SWD) to human absence seizures both behaviourally and neuronally. Here, we report that Genetic Absence Epilepsy Rats from Strasbourg recapitulate the decreased neuroimaging signals and loss of consciousness characteristic of human absence seizures. Overall neuronal firing is decreased but rhythmic in the somatosensory cortex and thalamus during these seizures. Interestingly, individual neurons in both regions tend to consistently express one of four distinct patterns of seizure-associated activity. These patterns differ in firing rate dynamics and in rhythmicity during seizure. One group of neurons showed a transient initial peak in firing at SWD onset, accounting for the brief initial increase in overall neuronal firing seen in cortex and thalamus. The largest group of neurons in both cortex and thalamus showed sustained decreases in firing during SWD. Other neurons showed either sustained increases or no change in firing. These findings suggest that certain classes of cortical and thalamic neurons may be particularly responsible for the paroxysmal oscillations and consequent loss of consciousness in absence epilepsy.

neuroscience↗