Characteristic Changes of Prefrontal and Motor Areas in Patients with Type 2 Diabetes and Major Depressive Disorder During a Motor Task of Tai Chi Chuan: A Functional Near-Infrared Spectroscopy Study.

AIM: This cross-sectional study aims to identify the characteristic changes of prefrontal and motor areas during a tai chi chuan task in patients with Type 2 diabetes mellitus (T2DM) and major depressive disorder (MDD) using wearable functional near-infrared spectroscopy (fNIRS). METHODS: Three parallel groups (T2DM with DD group, T2DM group, and healthy group) were recruited from December 10, 2022, to May 31, 2023. Participants in three groups conducted a motor task of tai chi chuan designed by Eprime 3.0, and fNIRS was used to monitor the brain activation, functional connectivity (FC), and lateralization of prefrontal and motor areas. Correlation analyses were performed to examine the relationship between depressive symptoms and the function of prefrontal and motor areas. RESULTS: Ninety elder adults (aged ≥ 60), including 30 patients with T2DM and MDD, 30 patients with T2DM, and 30 healthy subjects, were enrolled. In contrast with the patients with T2DM and healthy subjects, the patients with T2DM and MDD had decreased activation and abnormal lateralization in prefrontal and motor areas and decreased FC among supplementary motor area, motor area, and dorsolateral prefrontal cortex (DLPFC). Furthermore, the oxyhemoglobin (HbO2) concentration value of DLPFC in patients with T2DM and MDD was negatively associated with scores of Hamilton Depression Scale-24 (HAMD-24). CONCLUSIONS: Patients with T2DM and MDD had characteristic functional changes in prefrontal and motor areas. DLPFC may be a potential target of diagnosis and intervention for patients with T2DM and MDD.

Odor lateralization test is insensitive to small degrees of intranasal trigeminal activation.

INTRODUCTION: Odors with prominent trigeminal compounds are more easily localized than purely olfactory ones. However, it is still unclear whether adding a small amount of a trigeminal compound to an olfactory odor significantly improves lateralization performance. METHODS: We included 81 healthy adults aged 25.4 ± 4.8 years to complete odor lateralization tasks using 12 odors: two "olfactory", two "trigeminal" odors, and eight odor mixtures at two low concentrations of "trigeminal" odors (4%, 8%). This task utilized a "Squeezer" delivering odor or air to either nostril, and participants indicated which nostril received the odor. Evaluations also included olfactory function, odor intensity ratings, and individual olfactory importance. RESULTS: Degrees of trigeminal compounds significantly affected lateralization performance (F = 82.32, p < 0.001), with 100% irritants showing higher performance than 0%, 4%, and 8% irritants (p's < 0.001), while no significant differences were found between odors with 0%, 4%, and 8% irritants (p's > 0.05). Chi-square tests confirmed higher percentages of above-chance lateralization with 100% irritants than with 0%, 4%, and 8% irritants (χ2 = 30.89 to 47.33, p's < 0.001). CONCLUSIONS: Adding a small amount of a trigeminal compound to a selective olfactory odor does not significantly improve lateralization performance. Trigeminal lateralization likely follows an "accumulative" pattern rather than an "all or none" rule. With only 20 trials, the task may lack sensitivity to detect low levels of trigeminal irritation in selective olfactory odors, though it does not rule out trigeminal activation. The odor lateralization task can screen for odors with prominent trigeminal compounds by comparing group-level performance with that of purely olfactory odors. Future studies should use more ideal stimuli (e.g., PEA for olfactory, CO2 for trigeminal) to test the replicability of the results.

A meta-analysis of cognitive flexibility in aging: Perspective from functional network and lateralization.

Cognitive flexibility, the ability to switch between mental processes to generate appropriate behavioral responses, is reduced with typical aging. Previous studies have found that age-related declines in cognitive flexibility are often accompanied by variations in the activation of multiple regions. However, no meta-analyses have examined the relationship between cognitive flexibility in aging and age-related variations in activation within large-scale networks. Here, we conducted a meta-analysis employing multilevel kernel density analysis to identify regions with different activity patterns between age groups, and determined how these regions fall into functional networks. We also employed lateralization analysis to explore the spatial distribution of regions exhibiting group differences in activation. The permutation tests based on Monte Carlo simulation were used to determine the significance of the activation and lateralization results. The results showed that cognitive flexibility in aging was associated with both decreased and increased activation in several functional networks. Compared to young adults, older adults exhibited increased activation in the default mode, dorsal attention, ventral attention, and somatomotor networks, while displayed decreased activation in the visual network. Moreover, we found a global-level left lateralization for regions with decreased activation, but no lateralization for regions with higher activation in older adults. At the network level, the regions with decreased activation were left-lateralized, while the regions with increased activation showed varying lateralization patterns within different networks. To sum up, we found that networks that support various mental functions contribute to age-related variations in cognitive flexibility. Additionally, the aging brain exhibited network-dependent activation and lateralization patterns in response to tasks involving cognitive flexibility. We highlighted that the comprehensive meta-analysis in this study offered new insights into understanding cognitive flexibility in aging from a network perspective.

Adult auditory brain responses to nestling begging calls in seasonal songbirds: an fMRI study in non-parenting male and female starlings (Sturnus vulgaris).

The present study aims to investigate whether begging calls elicit specific auditory responses in non-parenting birds, whether these responses are influenced by the hormonal status of the bird, and whether they reflect biparental care for offspring in the European starling (Sturnus vulgaris). An fMRI experiment was conducted to expose non-parenting male and female European starlings to recordings of conspecific nestling begging calls during both artificially induced breeding and non-breeding seasons. This response was compared with their reaction to conspecific individual warbling song motifs and artificial pure tones, serving as social species-specific and artificial control stimuli, respectively. Our findings reveal that begging calls evoke a response in non-parenting male and female starlings, with significantly higher responsiveness observed in the right Field L and the Caudomedial Nidopallium (NCM), regardless of season or sex. Moreover, a significant seasonal variation in auditory brain responses was elicited in both sexes exclusively by begging calls, not by the applied control stimuli, within a ventral midsagittal region of NCM. This heightened response to begging calls, even in non-parenting birds, in the right primary auditory system (Field L), and the photoperiod induced hormonal neuromodulation of auditory responses to offspring's begging calls in the secondary auditory system (NCM), bears resemblance to mammalian responses to hunger calls. This suggests a convergent evolution aimed at facilitating swift adult responses to such calls crucial for offspring survival.

Hemispheric asymmetries in borderline personality disorder: a systematic review.

Borderline personality disorder (BPD) is characterized by increased mood reactivity and affective instability. Since core structures involved in emotion processing, such as the amygdala, demonstrate strong lateralization, BPD is an interesting target for laterality research. So far, a systematic integration of findings on lateralization in BPD is missing. Therefore, we systematically reviewed studies published until February 2024 in PubMed, Web of Science, and PsycInfo databases that measured hemispheric asymmetries and behavioral lateralization in patients with BPD. Inclusion criteria were (a) diagnosis of BPD and (b) results on hemispheric or behavioral asymmetries. Specifically for neuroimaging studies, hemispheres need to be assessed separately. Review articles and studies with disorders other than BPD were excluded. Risk of bias was assessed with the Newcastle Ottawa Scale for non-randomized, non-comparative intervention studies. A total of 21 studies met the inclusion criteria. Thirteen studies investigated structural hemispheric asymmetries, five functional hemispheric asymmetries, two examined handedness, and one studied hemispheric asymmetry in visuospatial attention. Overall, studies examining structural asymmetries in BPD report bilateral volume reduction in the amygdala and hippocampus but a right-sided reduction in the orbitofrontal cortex. For functional lateralization, asymmetrical de/activation patterns in the default mode network in BPD and reduced right-frontal asymmetry were evident. Also, studies indicate a trend towards increased non-right-handedness in BPD. Risk factors for BPD, such as childhood abuse, may play a crucial role in the development of structural and functional alterations. However, the generalization of results may be limited by small sample sizes and varying study designs.

Topography and Lateralization of Nodal Metastases in Muscle-Invasive Bladder Cancer Using Super-Extended Pelvic Lymph Node Dissection with the Sentinel Lymph Node Technique.

Background: This study assessed the topography and lateralization of lymph node (LN) metastases in muscle-invasive bladder cancer (MIBC) patients using super-extended pelvic lymph node dissection (sePLND) with sentinel lymph node dissection (SLND). Methods: We analyzed 54 MIBC patients who underwent cystectomy with sePLND and SLND. Tumor location was classified using cystoscopy. Nanocolloid-Tc-99m was injected peritumorally. Preoperative SPECT/CT lymphoscintigraphy and an intraoperative gamma probe were used for SLN detection. Results: A total of 1414 LNs, including 192 SLNs, were resected from 54 patients. Metastases were found in 72 LNs from 22 patients (41%). The obturator fossa was the primary site for LN metastases (37.5%). SLNs were most common in the external iliac region (34.4%). In 36% of the patients with positive LNs, metastases were identified only through sePLND. In 9% of the patients, metastases were found solely in the pararectal region, identified through SLND. Tumor lateralization correlated with ipsilateral positive LNs, but 20% of the patients had contralateral metastases. Conclusions: The pararectal region may be the exclusive site for positive LNs in MIBC. The obturator fossa is the most prevalent region for LN metastases. Unilateral PLND should be avoided due to the risk of contralateral metastases. Combining sePLND with SLND improves staging.

The role of cricoarytenoid joint ankylosis in bilateral vocal cord immobility.

OBJECTIVES: To stratify the severity of cricoarytenoid joint fixation (CAJF) by surgery and understand the role of it played in the bilateral vocal fold immobility (BVFI). The second objective emphasizes on the significance of the preoperative differential diagnosis from neurogenic immobility with medical history and endoscopic findings. METHODS: A retrospective review was conducted of 74 patients between 2005 and 2022. Careful medical history inquiry, and videolaryngoscopy are conducted to recruit the appropriate surgical candidates. All patients underwent arytenoid remobilization (AR) followed by vocal fold medialization with arytenoid adduction (AA) or lateralization with suture lateralization (SL). The severity of CAJF is graded during the operation or inferred based on the period from operation to recurrence. RESULT: A total of 18 patients, aged between 18 and 76 years, were analyzed. Among them, 14 cases were classified as the adducted type with ventilation problems, with three presenting with dyspnea, and 11 requiring artificial airways. Additionally, four patients presented with the abducted type, characterized by aphonia. Meanwhile, two additional cases were considered for comparison but were not included in this cohort of 18 subjects due to incorrect diagnosis and inappropriate management. Using AR procedure, the AA procedure offered three aphonia subjects a voiced sound without airway impairment and the SL procedure decannulated 100% (11/11) of the artificial airways and improved the airway patency in 100% (3/3) of the non-tracheostomized subjects despite the severity of CAJF. The severity of joint ankylosis was distributed as follows: In the aphonia group, there were three subjects with grade I, one subject with grade II, and 0 subjects with grade III. In the ventilation group, there was one subject with grade I, seven subjects with grade II, and six subjects with grade III. In contrast, the two cases used for comparison experienced recurrent dyspnea and failed decannulation because the AR procedure was not performed. The follow-up period was averaged in 58 and 14 months at least. CONCLUSION: From this experience, it is the accurate preoperative diagnosis instead of the severity of CAJF that determines the successful rate in airway patency and voiced phonation if the AR procedure is utilized. Careful medical history inquiry and videolaryngoscopic examination can correctly differentiate the mechanical from neurogenic origin without the help of EMG. Evidence of level: 4.

How To Choose The Best Lateralization And Distalization Of The Reverse Shoulder Arthroplasty To Optimize The Clinical Outcome In Cuff Tear Arthropathy.

PURPOSE: Lateralization shoulder angle (LSA) and distalization shoulder angle (DSA) are two parameters that had been described for a better planification of the arthroplasty, but the range of these angles are very wide. The purpose of this study was to investigate the best combination in terms of lateralization and distalization to optimize the outcome of Reverse total shoulder arthroplasty(RTSA) for cuff tear arthropathy (CTA) with a functional deltoid. METHODS: This retrospective cohort study, conducted between 2014 and 2018 at a specialized shoulder unit in Paris, focused on patients exclusively treated with RTSA for CTA, ensuring a minimum follow-up of 1 year. The primary outcome measure was the ASES score. Secondary outcome measures included range of motion and patient-reported outcomes at the final follow-up, such as the Constant score, SSV, SST, and VAS. Optimal RTSA outcomes were delineated by scores surpassing the patient's acceptable symptom state (PASS) for ASES, set in literature at 76. Patients were categorized into two groups based on ASES scores at the last follow-up: those below and those above 76. The capabilities of LSA and DSA to predict the outcome of interest were assessed and the corresponding optimal thresholds for having better outcome were calculated using the Receiver Operator Characteristic (ROC) curve. RESULTS: Sixty-two patients were included in the study with a mean age of 74.51 ± 6.79. Correlation analysis revealed significant medium correlation between ASES and both LSA (r = -0.43, p = .001) and DSA (r = 0.39, p = .002). The DSA of patients with ASES > 76 was 48.55 ± 12.44 with an IQR of 39.5 - 57.5, as compared to lower values for patients with ASES < 76, which was 37.82 ± 9.8 (IQR 32 - 46.5) (p=0.009). Similarly, the LSA of patients with ASES > 76 was 86.43 ± 11.4 (IQR 79.5 - 93.5), as compared to higher values for patients with ASES < 76, which was 100.09 ± 7.63 (IQR 93 - 105.5) (p<0.001). The ROC curve confirmed LSA and DSA as good predictors for the ASES outcome, with AUCs of 0.851 and 0.741, respectively. The optimal LSA should be no more than 90.5° (Se=100%, Sp=67.7%). The optimal DSA should be no less than 37.5° (Se=78.4%, Sp=63.6%). CONCLUSION: The LSA and DSA angle could represent a helpful tool to optimize the clinical outcomes of an adaptable RTSA in CTA with a functional deltoid and a complete passive range of motion.

Brain Laterality in Dyslexia Seen during Literacy Development and Early Training.

During the period in which children learn to read and write, a gradual shift from right to left hemisphere dominance for language is typically seen. However, in children with dyslexia, a deviant pattern is described in the literature. As part of a larger longitudinal study (The Bergen Longitudinal Dyslexia Study), the present study aimed to assess this development from an early age before children learn to read and write. Dichotic listening (DL), which is a non-invasive test, was used to assess the development of brain laterality in a Typical group and a Dyslexia group. The participants received yearly sessions of evidence-based literacy training at ages 5 to 7. The Typical group showed increasing ear scores and a shift from no ear advantage in the Pre-literacy stage (age 6), indicative of no hemisphere dominance, to a right ear advantage, indicative of a left hemisphere dominance, in the Emergent literacy stage (age 8) and the Literacy stage (age 11). The Dyslexia group showed a different pattern, with a significant right ear advantage at age 6, indicative of a right hemisphere dominance, and increasing ear scores at ages 8 and 11; however, no ear dominance was observed in the Literacy stage. The results point to an effect of relevant, evidence-based training affecting both right and left hemispheres in dyslexia, which should form a basis for further research.

A retrospective study on post-operative recovery of daily living activity after total corpus callosotomy.

INTRODUCTION: Post-operative complications of corpus callosotomy (CC) in children, prolonged hospitalization due to inactivity as acute disconnection syndrome is occasionally experienced. We aimed to clarify this issue and its risk factors with a hypothesis that electroencephalogram (EEG) findings as measures of functional lateralization may be among prognostic factors for post-operative recovery. MATERIALS AND METHODS: Twenty-three patients with childhood-onset drug-resistant epilepsy who underwent total CC between April 2017 and December 2023 were included in the study and they were divided into two groups based on the duration of post-operative hospitalization as an indicator of recovery of daily living activity. We compared scalp EEG findings and the other factors including clinical characteristics between the two groups. RESULTS: Of 22 patients (14 males) without specific complications, post-operative hospitalization clustered in 9-14 days in 15 patients (Group A) with range 16-118 days in seven patients (Group B). The ratios of patients with non-lateralized spikes on pre-operative EEG and that of patients with symmetric background activity on post-operative EEG were significantly greater in Group B (7/7, 100 %; 6/7, 86 %, respectively) than in Group A (8/15, 53 %; 4/15, 27 %, respectively) (p = 0.038; p = 0.020, respectively, by Fisher's exact test), while other factors were not significantly different between the two groups. CONCLUSIONS: Delayed recovery of living activity should be anticipated, especially in patients with non-lateralized epileptic discharges on pre-operative EEG.

Evaluating the gonads of left-handed children using ultrasonography and comparing the findings with those of right-handed ones.

Hand use varies according to which brain hemisphere is dominant. Early androgen exposure causes right hemisphere dominance. This study is aimed at comparing the testes and ovary sizes of healthy left-handed girls and boys with those of healthy right-handed children and investigating whether or not lateralization affects the gonads. The ovarian and testicular sizes of healthy left- and right-handed boys and girls who were similar in height, weight, and age were compared by ultrasonography. One hundred and eleven (111) children-including 26 left- and 26 right-handed girls and 31 left- and 28 right-handed boys-were included in this study. The mean age of left-handed girls was 77.2 ± 25.3 months, and the mean age of right-handed girls was 74.4 ± 25.2 months. Right transverse diameter (p = 0.004), right longitudinal diameter (p = 0.009), and right ovarian volume (p = 0.020) were larger in left-handed girls above 8 years of age than in left-handed girls below 8 years of age. However, these values were similar in right-handed girls above and below 8 years of age. In right-handed girls, the transverse diameter was larger in the right ovary than in the left ovary (0.014). Other ovarian values were similar. The mean age of left-handed boys was 85.2 ± 41.3 months, whereas the mean age of right-handed ones was 81 ± 41.2 months. Prepubertal and pubertal right- and left-handed boys had similar mean right and left testicular diameters and volumes (p > 0.05). CONCLUSION: Lateralization affected gonad size in girls. In boys, gonads were not affected by lateralization. Cerebral lateralization may affect the hypothalamic-pituitary-gonadal axis in girls. WHAT IS KNOWN: • Hand use varies according to which cerebral hemisphere is dominant. Males tend to be more left-handed than females. Brain asymmetry can affect the neuroendocrine axis. WHAT IS NEW: • Ultrasonographic gonadal dimensions were examined in left-handed and right-handed children. Cerebral lateralization may affect the hypothalamic-pituitary-gonadal axis in girls.

No evidence of altered language laterality in people who stutter across different brain imaging studies of speech and language.

A long-standing neurobiological explanation of stuttering is the incomplete cerebral dominance theory, which refers to competition between two hemispheres for 'dominance' over handedness and speech, causing altered language lateralization. Renewed interest in these ideas came from brain imaging findings in people who stutter of increased activity in the right hemisphere during speech production or of shifts in activity from right to left when fluency increased. Here, we revisited this theory using functional MRI data from children and adults who stutter, and typically fluent speakers (119 participants in total) during four different speech and language tasks: overt sentence reading, overt picture description, covert sentence reading and covert auditory naming. Laterality indices were calculated for the frontal and temporal lobes using the laterality index toolbox running in Statistical Parametric Mapping. We also repeated the analyses with more specific language regions, namely the pars opercularis (Brodmann area 44) and pars triangularis (Brodmann area 45). Laterality indices in people who stutter and typically fluent speakers did not differ, and Bayesian analyses provided moderate to anecdotal levels of support for the null hypothesis (i.e. no differences in laterality in people who stutter compared with typically fluent speakers). The proportions of the people who stutter and typically fluent speakers who were left lateralized or had atypical rightward or bilateral lateralization did not differ. We found no support for the theory that language laterality is reduced or differs in people who stutter compared with typically fluent speakers.

A gender and size specific evaluation of Grammont-type inlay versus lateralizing onlay stem designs in achieving lateralization and distalization in reverse shoulder arthroplasty.

INTRODUCTION: In reverse shoulder arthroplasty (RSA) new designs enable greater amounts of lateralization to prevent instability and scapular notching and increase range of motion, however, excessive lateralization leads to stress upon the acromion that can result in scapular spine fatigue fractures. Aim of this study was to gender- and size-specifically assess the influence of glenosphere size and different humeral designs on lateralization, distalization, and bony impingement-free range of motion (ROM) in patients undergoing RSA. METHODS: Computed tomography scans from 30 osteoarthritic patients (f:15, m:15) and 20 cuff tear arthropathy patients (f:10, m:10) were used to virtually simulate RSA implantation. The efficacy of an inlay Grammont-type system vs. an onlay lateralizing system combined with different glenosphere sizes (36 mm vs. 42 mm) in achieving ROM, lateralization, and distalization was evaluated. Moreover, gender and patient's constitution were correlated to humeral size by radiologically measuring the best-fit circle of the humeral head. RESULTS: A different amount of relative lateralization was achieved in both genders using large glenospheres and onlay designs. Latter yielded a higher ROM in all planes for men and women with a 42 mm glenosphere; with the 36 mm glenosphere, an increased ROM was observed only in men. The 155° inlay design led to joint medialization only in men, whereas all designs led to lateralization in women. When adjusting the absolute amount of lateralization to humerus' size (or patient's height), regardless of implant type, women received greater relative lateralization using 36 mm glenosphere (inlay: 1%; onlay 12%) than men with 42 mm glenosphere (inlay: -3%; onlay: 8%). CONCLUSION: The relative lateralization achieved using onlay design is much higher in women than men. Small glenospheres yield greater relative lateralization in women compared to large glenospheres in men. Humeral lateralization using onlay designs should be used cautiously in women, as they lead to great relative lateralization increasing stress onto the acromion. LEVEL OF EVIDENCE: Basic Science Study, Computer Modeling.

Reduced lateralization of the language network in the blind and its relationship with white matter tract neuroanatomy.

Several previous studies reported reduced leftward lateralization in blind participants' samples compared to the sighted population. The origins of this difference remain unknown. Here, we tested whether functional lateralization is connected with the structural characteristics of white matter tracts [corpus callosum (CC), uncinate fasciculus (UF), and superior longitudinal fasciculus (SLF)], as suggested by previous studies conducted in the typical sighted population. Twenty-three blind and 21 sighted adult participants were tested during fMRI with a semantic decision paradigm presented both auditorily and in the modality appropriate for reading (tactually for the blind and visually for the sighted). Lateralization indices (LI) were calculated based on the activations. The fractional anisotropy (FA) measure was extracted from the white matter tracts of interest. Correlation analyses testing the relationship between FA and LI were conducted. The reduced leftward lateralization of both speech processing and reading-related activations was replicated. Nevertheless, the relationship between the structural integrity of the CC and LI and between the asymmetry of the intrahemispheric tracts and LI was not confirmed, possibly due to the lack of power. The sources of the reduced lateralization of the language network in the sensory-deprived population remain unknown. Further studies should account for environmental variables (e.g., the frequency of contact with written language) and the complexity of the factors that may influence the functional lateralization of the human brain.

Musicianship and Prominence of Interhemispheric Connectivity Determine Two Different Pathways to Atypical Language Dominance.

During infancy and adolescence, language develops from a predominantly interhemispheric control-through the corpus callosum (CC)-to a predominantly intrahemispheric control, mainly subserved by the left arcuate fasciculus (AF). Using multimodal neuroimaging, we demonstrate that human left-handers (both male and female) with an atypical language lateralization show a rightward participation of language areas from the auditory cortex to the inferior frontal cortex when contrasting speech to tone perception and an enhanced interhemispheric anatomical and functional connectivity. Crucially, musicianship determines two different structural pathways to this outcome. Nonmusicians present a relation between atypical lateralization and intrahemispheric underdevelopment across the anterior AF, hinting at a dysregulation of the ontogenetic shift from an interhemispheric to an intrahemispheric brain. Musicians reveal an alternative pathway related to interhemispheric overdevelopment across the posterior CC and the auditory cortex. We discuss the heterogeneity in reaching atypical language lateralization and the relevance of early musical training in altering the normal development of language cognitive functions.

Exploring the Asymmetric Body's Influence on Interval Timing Behaviors of Drosophila melanogaster.

The roles of brain asymmetry in Drosophila are diverse, encompassing the regulation of behavior, the creation of memory, neurodevelopment, and evolution. A comprehensive examination of the Drosophila brain has the potential to enhance our understanding of the functional significance of brain asymmetry in cognitive and behavioral processes, as well as its role in evolutionary perspectives. This study explores the influence of brain asymmetry on interval timing behaviors in Drosophila, with a specific focus on the asymmetric body (AB) structure. Despite being bilaterally symmetric, the AB exhibits functional asymmetry and is located within the central complex of the fly brain. Interval timing behaviors, such as rival-induced prolonged mating duration: longer mating duration behavior (LMD) and sexual experience-mediated shorter mating duration behavior (SMD), are essential for Drosophila. We utilize genetic manipulations to selectively activate or inhibit AB neurons and evaluates their impact on LMD and SMD behaviors. The results indicate that specific populations of AB neurons play unique roles in orchestrating these interval timing behaviors. Notably, inhibiting GAL4R38D01-labeled AB neurons disrupts both LMD and SMD, while GAL4R42C09 neuron inhibition affects only LMD. Moreover, hyperexcitation of GAL4R72A10-labeled AB neurons perturbs SMD. Our study identifies NetrinB (NetB) and Abdominal-B (Abd-B) are important genes for AB neurons in LMD and highlights the role of 5-HT1B neurons in generating LMD through peptidergic Pigment-dispersing factor (PDF) signaling. In summary, this study underscores the importance of AB neuron asymmetry in mediating interval timing behaviors and provides insights into the underlying mechanisms of memory formation and function in Drosophila.

Association between situs inversus and maternal SARS-CoV-2 infection at gestational age 4-6 weeks.

BACKGROUND: A dramatic increase in fetal situs inversus diagnoses by ultrasound in the months following the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) surge of December 2022 in China led us to investigate whether maternal SARS-CoV-2 exposure could be associated with elevated risk of fetal situs inversus. METHODS: In this multi-institutional, hospital-based, matched case-control study, we investigated pregnant women who underwent ultrasonographic fetal biometric assessment at gestational weeks 20-24 at our hospitals. Each pregnant woman carrying a situs inversus fetus was randomly matched with four controls based on the date of confinement. Relevant information, including SARS-CoV-2 infection, and other potential risk factors were collected. Conditional logistic regression was used to test possible associations between fetal situs inversus and SARS-CoV-2 infection at different gestational weeks as well as individual risk factors. FINDINGS: A total of 52 pregnant women diagnosed with fetal situs inversus between January 1 and October 31, 2023 and 208 matched controls with normal fetuses were enrolled. We found no association between an increased risk of fetal situs inversus with gestational SARS-CoV-2 infection or with other risk factors. However, fetal situs inversus was significantly associated with SARS-CoV-2 infection specifically in gestational weeks 4-6 (adjusted odds ratio [aOR] 6.54 [95% confidence interval 1.76-24.34]), but not with infection at other gestational ages, after adjusting for covariates. CONCLUSIONS: Increased risk of fetal situs inversus is significantly associated with maternal SARS-CoV-2 infection at gestational weeks 4-6, corresponding to the fetal developmental window for visceral lateralization in humans. FUNDING: National Key R&D Program of China, etc.

Alterations of contralesional hippocampal subfield volumes and relations to cognitive functions in patients with unilateral stroke.

BACKGROUND: The volumes of the hippocampal subfields are related to poststroke cognitive dysfunctions. However, it remains unclear whether contralesional hippocampal subfield volume contributes to cognitive impairment. This study aimed to investigate the volumetric differences in the contralesional hippocampal subfields between patients with left and right hemisphere strokes (LHS/RHS). Additionally, correlations between contralesional hippocampal subfield volumes and clinical outcomes were explored. METHODS: Fourteen LHS (13 males, 52.57 ± 7.10 years), 13 RHS (11 males, 51.23 ± 15.23 years), and 18 healthy controls (11 males, 46.94 ± 12.74 years) were enrolled. Contralesional global and regional hippocampal volumes were obtained with T1-weighted images. Correlations between contralesional hippocampal subfield volumes and clinical outcomes, including the Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE), were analyzed. Bonferroni correction was applied for multiple comparisons. RESULTS: Significant reductions were found in contralesional hippocampal as a whole (adjusted p = .011) and its subfield volumes, including the hippocampal tail (adjusted p = .005), cornu ammonis 1 (CA1) (adjusted p = .002), molecular layer (ML) (adjusted p = .004), granule cell and ML of the dentate gyrus (GC-ML-DG) (adjusted p = .015), CA3 (adjusted p = .009), and CA4 (adjusted p = .014) in the RHS group compared to the LHS group. MoCA and MMSE had positive correlations with volumes of contralesional hippocampal tail (p = .015, r = .771; p = .017, r = .763) and fimbria (p = .020, r = .750; p = .019, r = .753) in the LHS group, and CA3 (p = .007, r = .857; p = .009, r = .838) in the RHS group, respectively. CONCLUSION: Unilateral stroke caused volumetric differences in different hippocampal subfields contralesionally, which correlated to cognitive impairment. RHS leads to greater volumetric reduction in the whole contralesional hippocampus and specific subfields (hippocampal tail, CA1, ML, GC-ML-DG, CA3, and CA4) compared to LHS. These changes are correlated with cognitive impairments, potentially due to disrupted neural pathways and interhemispheric communication.

Brain asymmetry as minimization of free energy: a theoretical model.

The asymmetry between the left and right sides seems to be a general principle of organization of the nervous systems in Bilateria, providing the foundations for a plethora of leftward and rightward biases in behaviour as documented in species ranging from Caenorhabditis elegans nematodes to humans. Several theories have been put forward to account for the existence and maintenance in the evolution of the asymmetric organization of the brain at both individual and population levels. However, what is missing in theorizing about the evolution of brain asymmetry is an overarching general hypothesis that may subsume all different aspects of current models. Here, we tried to provide an overarching general framework based on the energy and free-energy minimization principle, which proved so valuable in other areas of neuroscience. We found that at the individual level the antisymmetric singlet configuration realizes the lowest energy state of the system, whereas at the group level, the spontaneous emergence of directional asymmetry arises as a consequence of the minimization of the free energy of the system, which guarantees its stability and equilibrium. We thus argue that the various phenomenological aspects of brain asymmetry that have been captured in biology-e.g. sparing of neural tissue, control of unitary motor responses and, at the population level, evolutionarily stable strategies described by mathematical games theory-may be thought of as the manifestation of a more general principle of energy minimization generating, among others, asymmetry of the brains.

Lateralized Subthalamic Stimulation for Axial Dysfunction in Parkinson's Disease: Exploratory Outcomes and Open-Label Extension.

BACKGROUND: A randomized trial suggested that reducing left-sided subthalamic stimulation amplitude could improve axial dysfunction. OBJECTIVES: To explore open-label tolerability and associations between trial outcomes and asymmetry data. METHODS: We collected adverse events in trial participants treated with open-label lateralized settings for ≥3 months. We explored associations between trial outcomes, location of stimulation and motor asymmetry. RESULTS: 14/17 participants tolerated unilateral amplitude reduction (left-sided = 10, right-sided = 4). Two hundred eighty-four left-sided and 1113 right-sided stimulated voxels were associated with faster gait velocity, 81 left-sided and 22 right-sided stimulated voxels were associated with slower gait velocity. Amplitude reduction contralateral to shorter step length was associated with 2.4-point reduction in axial MDS-UPDRS. Reduction contralateral to longer step length was associated with 10-point increase in MDS-UPDRS. CONCLUSIONS: Left-sided amplitude reduction is potentially more tolerable than right-sided amplitude reduction. Right-sided more than left-sided stimulation could be associated with faster gait velocity. Shortened step length might reflect contralateral overstimulation.