Cerebral cortex and autonomic nervous system responses during emotional memory processing

Can we gain translational insights into the functional roles of cerebral cortex from acortical rodent and naturally acortical zebrafish models?

Cerebral cortex is found only in mammals and is particularly prominent and developed in humans. Various rodent models with fully or partially ablated cortex are commonly used to probe the role of cortex in brain functions and its multiple subcortical projections, including pallium, thalamus and the limbic system. Various rodent models are traditionally used to study the role of cortex in brain functions. A small teleost fish, the zebrafish (Danio rerio), has gained popularity in neuroscience research, and albeit (like other fishes) lacking cortex, its brain performs well some key functions (e.g., memory, consciousness and motivation) with complex, context-specific and well-defined behaviors. Can rodent and zebrafish models help generate insights into the role of cortex in brain functions, and dissect its cortex-specific (vs. non-cortical) functions? To address this conceptual question, here we evaluate brain functionality in intact vs. decorticated rodents and further compare it in the zebrafish, a naturally occurring acortical species. Overall, comparing cortical and acortical rodent models with naturally acortical zebrafish reveals both distinct and overlapping contributions of neocortex and 'precortical' zebrafish telencephalic regions to higher brain functions. Albeit morphologically different, mammalian neocortex and fish pallium may possess more functional similarities than it is presently recognized, calling for further integrative research utilizing both cortical and decorticated/acortical vertebrate model organisms.

Evaluation of relationship between memory and temperament in 18-28 years old students

Background

Mizaj (Temperament) is a concept to express individual differences in Persian medicine and according to this theory, there is a relationship between Mizaj type and the abilities of different body organs. This cross-sectional study aimed to investigate the relationship between the type of Mizaj and the memory score (Quotient).

Methods

The target population was the 18 to 38 years old students of Babol University of Medical Sciences. Mojahedi's Mizaj questionnaire (MMQ) was used for determining the whole Mizaj. The physical Persian version of Wechsler Memory Scale III (WMS III) was used to assess memory score. The collected data were analyzed by SPSS Version 22 and the chi square (x2) and t-test were run and p- value 0.05 was considered as significant difference.

Results

Forty-two of participants were females and 18 were males. The average age of them was 23.6 (21-27). The average of Memory Quotient (MQ) was 122.1 ± 5.7. The average of MQ in warm Mizaj was 125.46 ± 1.2 and in cold Mizaj was 118.79 ± 6.5. The difference between two groups is statistically significant (p< 0.001). The average of MQ in dry Mizaj was 124.16 ± 2.67 and in wet Mizaj was 118.40 ± 7.64. The difference between two groups is statistically significant (P= 0.005).

Conclusion

The results showed there are significant relationship between memory score and warm/cold Mizaj and dry /wet Mizaj. It means students with warm or dry Mizaj had better memory score than students with cold or wet Mizaj. This relation was also detected between subtypes of memory and Mizaj expect between working memory and dry/wet Mizaj. These results are in accordance with theories in PM which indicate people with warm Mizaj and dry Mizaj have better memory and people with cold Mizaj and wet Mizaj have weaker memory and are more at risk of memory dysfunction.

Experimental models of human cortical malformations: from mammals to 'acortical' zebrafish

Human neocortex controls and integrates cognition, emotions, perception and complex behaviors. Aberrant cortical development can be triggered by multiple genetic and environmental factors, causing cortical malformations. Animal models, especially rodents, are a valuable tool to probe molecular and physiological mechanisms of cortical malformations. Complementing rodent studies, the zebrafish (Danio rerio) is an important model organism in biomedicine. Although the zebrafish (like other fishes) lacks neocortex, here we argue that this species can still be used to model various aspects and brain phenomena related to human cortical malformations. We also discuss novel perspectives in this field, covering both advantages and limitations of using mammalian and zebrafish models in cortical malformation research. Summarizing mounting evidence, we also highlight the importance of translationally-relevant insights into the pathogenesis of cortical malformations from animal models, and discuss future strategies of research in the field.

Repetitive transcranial magnetic stimulation improves cardiovascular autonomic nervous system control: A meta-analysis

BACKGROUND

Cardiovascular autonomic system (ANS) may be affected by altered neural activations in the brain. This systematic review and meta-analysis investigated potential effects of repetitive transcranial magnetic stimulation (rTMS) protocols on cardiovascular ANS control.

METHODS

Through 19 qualified studies, we acquired 70 comparisons for data synthesis. Individual effect sizes were estimated by comparing changes in following cardiovascular ANS control variables between active and sham stimulation conditions: (a) blood pressure (BP), (b) heart rate (HR), and (c) heart rate variability (HRV). Moreover, two moderator variable analyses determined whether changes in cardiovascular ANS control were different based on (a) rTMS protocols (excitatory rTMS versus inhibitory rTMS) and (b) specific targeted cortical regions, respectively.

RESULTS

The random-effects model meta-analysis revealed significant improvements in cardiovascular ANS control after the rTMS protocols. Specifically, applying excitatory and inhibitory rTMS protocols significantly decreased values of BP and HR variables. For HRV variables, excitatory rTMS protocols showed significant positive effects. These improvements in cardiovascular ANS control were observed while applying either excitatory rTMS protocols to the left dorsolateral prefrontal cortex or inhibitory rTMS protocols to the right dorsolateral prefrontal cortex.

LIMITATIONS

Relatively small number of studies for inhibitory rTMS on the right dorsolateral prefrontal cortex were included in this meta-analysis.

CONCLUSION

These findings suggest that applying excitatory and inhibitory rTMS protocols on prefrontal cortical regions may be effective to improve cardiovascular ANS control.

Measuring effects of height on the autonomic nervous system in middle-aged adolescents using the very low frequency band of heart rate variability

Previous studies have revealed the association between falling accidents and stress, measured via heart rate variability (HRV). However, none have studied this association using the very low frequency (VLF) band of HRV in adolescent populations. This study aimed to fill this gap by recruiting 90 adolescents to perform a light physical task at varying heights. Heart rates were used to calculate short-term HRV. The results showed a positive correlation between VLF bands and parasympathetic indices and a negative correlation with sympathetic indices, demonstrating the balancing effects of the autonomic modulation associated with height. The lowest VLF bands were obtained as 79.25 ms² at 10 m (p < 0.001) and 62.87 ms² at 9 m (p < 0.001) for the experienced and non-experienced male groups, respectively, and 28.09 ms² at 6 m (p = 0.001) for the female group. The results also suggested the need for a relatively lower height restriction for female adolescents than for males.Practitioner summary: Increased working heights can cause stress, which leads to falling accidents. The very low frequency band was shown to be associated with parasympathetic and sympathetic indices. Furthermore, the results suggested that the height limit necessary for providing a safe working environment may be lower for female adolescents than for males.Abbreviations: HRV: heart rate variability; VLF: very low frequency; ms2: absolute power; ANS: autonomic nervous system; PNS: parasympathetic nervous system; SNS: sympathetic nervous system; RR: intervals between two successive peaks of R waves; RMSSD: root mean square of successive RR interval differences; SD1: Poincaré plot index of standard deviation 1; SD2: Poincaré plot index of standard deviation 2; HF: high frequency; LF: low frequency; BMI: body mass index; ECG: electrocardiography; HR: heart rate; FFT: fast Fourier transformation; IQR: interquartile range; r: non-parametric partial correlation coefficient; η2: eta-squared; EM: experienced males; NM: non-experienced males; NF: non-experienced females; EEG: electroencephalogram.

Allelic Variants Within the ABO Blood Group Phenotype Confer Protection Against Critical COVID-19 Hospital Presentation

Introduction: Coronavirus disease 2019 (COVID-19) disease severity differs widely due to numerous factors including ABO gene-derived susceptibility or resistance. The objective of this study was to investigate the association of the ABO blood group and genetic variations of the ABO gene with COVID-19 severity in a heterogeneous hospital population sample from the United Arab Emirates, with the use of an epidemiological and candidate gene approach from a genome-wide association study (GWAS). Methods: In this cross-sectional study, a total of 646 participants who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were recruited from multiple hospitals and population-based (quarantine camps) recruitment sites from March 2020 to February 2021. The participants were divided into two groups based on the severity of COVID-19: noncritical (n = 453) and critical [intensive care unit (ICU) patients] (n = 193), as per the COVID-19 Reporting and Data System (CO-RADS) classification. The multivariate logistic regression analysis demonstrated the association of ABO blood type as well as circulating anti-A antibodies and anti-B antibodies as well as A and B antigens, in association with critical COVID-19 hospital presentation. A candidate gene analysis approach was conducted from a GWAS where we examined 240 single nucleotide polymorphisms (SNPs) (position in chr9: 136125788-136150617) in the ABO gene, in association with critical COVID-19 hospital presentation. Results: Patients with blood group O [odds ratio (OR): 0.51 (0.33, 0.79); p = 0.003] were less likely to develop critical COVID-19 symptoms. Eight alleles have been identified to be associated with a protective effect of blood group O in ABO 3'untranslated region (UTR): rs199969472 (p = 0.0052), rs34266669 (p = 0.0052), rs76700116 (p = 0.0052), rs7849280 (p = 0.0052), rs34039247 (p = 0.0104), rs10901251 (p = 0.0165), rs9411475 (p = 0.0377), and rs13291798 (p = 0.0377). Conclusion: Our findings suggest that there are novel allelic variants that link genetic variants of the ABO gene and ABO blood groups contributing to the reduced risk of critical COVID-19 disease. This study is the first study to combine genetic and serological evidence of the involvement of the ABO blood groups and the ABO gene allelic associations with COVID-19 severity within the Middle Eastern population.