Follow-up of cognitive impairment and inflammatory profile in individuals with mild COVID-19

Individuals who experience mild COVID-19 can suffer from long-lasting cognitive symptoms. Notably, 26% of these individuals experience difficulties with visuospatial abilities six months after infection. However, among those who initially exhibited visuoconstructive impairments, 66% showed improvement or complete reversal over time. Additionally, changes in cytokine levels, particularly CCL11, HGF, and CXCL10, were observed. These results suggest a potential link between ongoing cognitive issues and elevated levels of pro-inflammatory cytokines, which merits further investigation.

Effects of antipsychotics on intestinal motility in zebrafish larvae

BACKGROUND

Antipsychotics are essential for the treatment of schizophrenia. However, due to side effects, both continuity of treatment and patients' general health can be jeopardized. Some of these drugs, especially clozapine, have a class of side effects attributed to their antimuscarinic properties, such as dysmotility, a condition in which muscles of the digestive system become impaired. Dysmotility may also alter the speed, strength or coordination of the digestive organs, causing distention, disturbing gastrointestinal transit, leading to symptoms such as bloating, nausea, vomiting, and even malnutrition. In this study, our aim was to develop an in vivo assay capable of identifying and studying the antimuscarinic effects of antipsychotics in a zebrafish model.

METHODS

We performed video recordings of in vivo 5-day postfertilization (dpf) zebrafish larvae gastrointestinal tracts and analyzed the frequency of spontaneous and regular cycles of contractions of the gut.

KEY RESULTS

The assay was first validated with treatment with atropine. We showed that this antimuscarinic drug reduces peristaltic cycles. Subsequently, the larvae were treated with the antipsychotics haloperidol, risperidone, and clozapine. Neither haloperidol nor risperidone reduced gut motility, but clozapine significantly reduced the frequency of cycles of contractions (P<.0001), which confirms the existing clinical data.

CONCLUSIONS & INFERENCES

We conclude that this zebrafish assay efficiently identifies anticholinergic side effects of antipsychotics, and can thus be a quick and useful way to screen for this property in new drugs.

Analysis of telomere attrition in bipolar disorder

BACKGROUND

Telomeres can be considered a marker of biological aging. Studies have suggested that telomere shortening may be associated with aging related diseases and also psychiatric disorders.

OBJECTIVES

Investigate whether bipolar disorder (BD) and its clinical specificities are associated with telomere shortening.

METHODS

Eighty-five BD patients and 95 healthy controls were paired for age, sex and educational level. Volunteers were submitted to a psychiatric interview and clinical evaluation. Patients and controls were compared as a whole sample and within specific telomere range (short and long telomeres). Intrapatients group comparison involved type of BD and comorbidities. A Real Time Quantitative PCR was performed in order to verify leukocytes telomere length.

RESULTS

Bipolar disorder patients presented shorter telomeres when compared to controls (p<0.001). However, there was no significant difference in telomere length between different BD subtypes. When two groups of patients (long and short telomeres) were compared, only panic disorder showed an association with telomere categories (χ(2)=6.91; p=0.009; OR=4.27).

LIMITATIONS

It was not possible to collect information about time since diagnosis, which limited conclusions regarding BD chronicity and telomere length. Furthermore, medication interference upon telomere length was not controlled.

CONCLUSIONS

Results suggest that BD is associated with reduced telomere length. Also, panic comorbidity may represent an additive risk factor. Understanding aspects that contribute to determination of telomere size in bipolar patients allows us to understand what the impact on telomeres size is, which is a health vulnerability marker.

Sarcosine preconditioning induces ischemic tolerance against global cerebral ischemia

Brain ischemic tolerance is an endogenous protective mechanism activated by a preconditioning stimulus that is closely related to N-methyl-d-aspartate receptor (NMDAR). Glycine transporter type 1 (GlyT-1) inhibitors potentiate NMDAR and suggest an alternative strategy for brain preconditioning. The aim of this work was to evaluate the effects of brain preconditioning induced by sarcosine, a GlyT-1 inhibitor, against global cerebral ischemia and its relation to NMDAR. Sarcosine was administered over 7 days (300 or 500 mg/kg/day, ip) before the induction of a global cerebral ischemia model in Wistar rats (male, 8-week-old). It was observed that sarcosine preconditioning reduced cell death in rat hippocampi submitted to cerebral ischemia. Hippocampal levels of glycine were decreased in sarcosine-treated animals, which was associated with a reduction of [(3)H] glycine uptake and a decrease in glycine transporter expression (GlyT-1 and GlyT-2). The expression of glycine receptors and the NR1 and NR2A subunits of NMDAR were not affected by sarcosine preconditioning. However, sarcosine preconditioning reduced the expression of the NR2B subunits of NMDAR. In conclusion, these data demonstrate that sarcosine preconditioning induces ischemic tolerance against global cerebral ischemia and this neuroprotective state is associated with changes in glycine transport and reduction of NR2B-containing NMDAR expression.

NCS-1 deficiency causes anxiety and depressive-like behavior with impaired non-aversive memory in mice

Sensing and regulating intracellular levels of calcium are essential for proper cellular function. In neurons, calcium sensing plays important roles in neuronal plasticity, neurotransmitter release, long-term synapse modification and ion channel activity. Neuronal calcium sensor-1 (NCS-1) is a member of the highly conserved neuronal calcium sensor family. Although NCS-1 has been associated with psychiatric conditions including autism, bipolar disorder and schizophrenia, it is unclear which role NCS-1 plays in behavior. To understand the involvement of NCS-1 in psychiatric conditions, we provided a comprehensive behavioral characterization of NCS-1 knockout (KO) mice. These mice grow and develop normally without apparent abnormalities in comparison to wild type littermates. However, open field showed that NCS-1 deficiency impairs novelty-induced exploratory activity in both KO and heterozygote (HT) mice. Moreover, NCS-1-deficiency also resulted in anxiety- and depressive-like behaviors as demonstrated by elevated plus maze, large open field, forced swim and tail suspension tasks. Furthermore, based on spontaneous object recognition test, non-aversive long-term memory was impaired in NCS-1 KO mice. In contrast, neither social behavior nor a kind of aversive memory was affected under NCS-1 deficiency. These data implicate NCS-1 in exploratory activity, memory and mood-related behaviors, suggesting that NCS-1 gene ablation may result in phenotypic abnormalities associated with neuropsychiatric disorders.

Sociodemographic characteristics, clinical factors, and genetic polymorphisms associated with Alzheimer's disease

OBJECTIVE

Alzheimer's disease (AD) has a multifactorial etiology involving an interaction of genetic and environmental factors. The Apolipoprotein E ε4 (ApoE ε4) is the single most important genetic risk factor for sporadic AD. Our aim was to study the association between sociodemographic, clinical data and gene polymorphisms in patients with sporadic AD in a heterogeneous genomic Brazilian population with low educational levels.

METHODS

We selected 169 sporadic AD patients and 97 controls older than 65 years and compared co-variables between them: age, years of education, vascular risk factors, genomic ancestry, and functional polymorphisms of ApoE, BDNF, COMT, and 5-HTTLPR. We also determined the genomic ancestry of all individuals.

RESULTS

The average years of education was significantly smaller in the patient's group (p = 0.003), and they had a history of depression when compared with controls (p < 0.001). The carriers of ApoE ε4 have an earlier onset of the disease (76.9 years) (p = 0.001) than ApoE ε3 (79.5 years) (p = 0.024). Patients with Met allele of Val66Met have a tendency to later onset of disease (p = 0.056). There were no differences in the genomic ancestry between groups.

CONCLUSION

Low level of education and history of depression were associated with AD. Public policies and intensive observation of old-age patients with lifetime history of depression, especially APOE ε4 carriers, could improve the well-being of our population.

Molecular medicine: a path towards a personalized medicine

Psychiatric disorders are among the most common human illnesses; still, the molecular and cellular mechanisms underlying their complex pathophysiology remain to be fully elucidated. Over the past 10 years, our group has been investigating the molecular abnormalities in major signaling pathways involved in psychiatric disorders. Recent evidences obtained by the Instituto Nacional de Ciência e Tecnologia de Medicina Molecular (National Institute of Science and Technology - Molecular Medicine, INCT-MM) and others using behavioral analysis of animal models provided valuable insights into the underlying molecular alterations responsible for many complex neuropsychiatric disorders, suggesting that "defects" in critical intracellular signaling pathways have an important role in regulating neurodevelopment, as well as in pathophysiology and treatment efficacy. Resources from the INCT have allowed us to start doing research in the field of molecular imaging. Molecular imaging is a research discipline that visualizes, characterizes, and quantifies the biologic processes taking place at cellular and molecular levels in humans and other living systems through the results of image within the reality of the physiological environment. In order to recognize targets, molecular imaging applies specific instruments (e.g., PET) that enable visualization and quantification in space and in real-time of signals from molecular imaging agents. The objective of molecular medicine is to individualize treatment and improve patient care. Thus, molecular imaging is an additional tool to achieve our ultimate goal.