Prolonged functional cerebral asymmetry as a consequence of dysfunctional parvocellular paraventricular hypothalamic nucleus signaling: An integrative model for the pathophysiology of bipolar disorder

Linking hearts and minds: understanding the cardiovascular impact of bipolar disorder

Bipolar disorder is a severe and recurring condition that has become a significant public health issue globally. Studies indicate a heightened risk and earlier onset of cardiovascular diseases among individuals with bipolar disorder, potentially increasing mortality rates. The chronic nature of bipolar disorder leads to disturbances across multiple systems, including autonomic dysfunction, over-activation of the hypothalamic-pituitary-adrenal axis and increased levels of peripheral inflammatory markers. These disruptions cause endothelial damage, the formation of plaques and blood clots, in addition to the medications used to treat bipolar disorder and genetic associations contributing to cardiovascular disease development. Understanding the complex interplay between bipolar disorder and cardiovascular events is essential for the prevention and effective management of cardiovascular conditions in individuals with bipolar disorder.

Cerebral asymmetry in bipolar disorders: A scoping review

Current brain stimulation protocols for patients with bipolar disorders propose brain stimulation according to a model of opposing cerebral dominance in mania and bipolar depression by stimulating the right or left dorsolateral prefrontal cortex during manic or depressive episodes, respectively. However, there is very little observational, rather than interventional, research on such opposing cerebral dominance. In fact, this is the first scoping review that summarizes resting-state and task- related functional cerebral asymmetries measured with brain imaging techniques in manic and depressive symptoms or episodes in patients with formal bipolar disorder diagnoses. In a three-step search process MEDLINE, Scopus, APA PsycInfo, Web of Science Core Collection, and BIOSIS Previews databases as well as reference lists of eligible studies were searched. Data from these studies were extracted with a charting table. Ten resting-state EEG and task-related fMRI studies met inclusion criteria. In line with brain stimulation protocols, mania relates to cerebral dominance in regions of the left frontal lobe, such as the left dorsolateral prefrontal cortex and dorsal anterior cingulate cortex. Bipolar depression relates to cerebral dominance in regions of the right frontal and temporal lobe, such as the right dorsolateral prefrontal cortex, orbitofrontal cortex and temporal pole. More observational research on cerebral asymmetries in mania and bipolar depression can advance brain stimulation protocols and potentially inform standard treatment protocols.

Heterogeneity of psychosocial functioning in patients with bipolar disorder: Associations with sociodemographic, clinical, neurocognitive and biochemical variables

OBJECTIVE

This study aims to identify the functional heterogeneity in fully or partially remitted patients with bipolar disorder and explore the correlations between psychosocial functioning and sociodemographic, clinical, neurocognitive and biochemical variables.

METHODS

One hundred and forty fully or partially remitted patients with bipolar disorder (BD) and seventy healthy controls were recruited. The patients were grouped into different profiles based on the Functioning Assessment Short Test (FAST) domain scores by hierarchical cluster analysis. The characteristics of subgroups and the correlations between psychosocial functioning and sociodemographic, clinical, neurocognitive and biochemical variables in each cluster were then analyzed.

RESULTS

There were three subgroups in fully or partially remitted patients with BD: the lower functioning group (LF), performed global functioning impairments; the moderate functioning group (MF), presented selective impairments in functional domains; and the good functioning subgroup (GF), performed almost intact functioning. Among the three subgroups, there were differences in FAST domains, sociodemographic variables, clinical variables, some neurocognitive domains and several biochemical indexes.

CONCLUSIONS

The study successfully identified three functional subgroups. The characteristics of discrete subgroups and the specific clinical factors, neurocognitive domains and biochemical indexes that are correlated with functional subgroups will allow for making tailored interventions to promote functional recovery and improve the quality of life.

Ouabain inhibitor rostafuroxin attenuates dextromethorphan-induced manic potential

Dextromethorphan (DM) abuse produces mania-like symptoms in humans. ERK/Akt signaling activation involved in manic potential can be attenuated by the inhibition of ouabain-like cardiac steroids. In this study, increased phosphorylations of ERK/Akt and hyperlocomotion induced by DM (30 mg/kg, i.p./day × 7) were significantly protected by the ouabain inhibitor rostafuroxin (ROSTA), suggesting that DM induces the manic potential. ROSTA significantly attenuated DM-induced protein kinase C δ (PKCδ) phosphorylation, GluN2B (i.e., MDA receptor subunit) expression, and phospho-PKCδ/GluN2B interaction. DM instantly upregulated the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent system. However, DM reduced Nrf2 nuclear translocation, Nrf2 DNA binding activity, γ-glutamylcysteine mRNA expression, and subsequent GSH/GSSG level and enhanced oxidative parameters following 1-h of administration. ROSTA, PKCδ inhibitor rottlerin, and GluN2B inhibitor traxoprodil significantly attenuated DM-induced alterations in Nrf2-related redox parameters and locomotor activity induced by DM in wild-type mice. Importantly, in PKCδ knockout mice, DM failed to alter the above parameters. Further, ROSTA and traxoprodil also failed to enhance PKCδ depletion effect, suggesting that PKCδ is a critical target for the anti-manic potential of ROSTA or GluN2B antagonism. Our results suggest that ROSTA inhibits DM-induced manic potential by attenuating ERK/Akt activation, GluN2B/PKCδ signalings, and Nrf2-dependent system.