Neural Pathways Research Articles

The role of the claustrum in the acquisition, consolidation and reconsolidation of memories in mice

The claustrum is a brain structure that remains shrouded in mystery due to the limited understanding of its cellular structure, neural pathways, functionality and physiological aspects. Significant research has unveiled connections spanning from the claustrum to the entire cortex as well as subcortical areas. This widespread connectivity has led to speculations of its role in integrating information from different brain regions, possibly contributing to processes such as attention, consciousness, learning and memory. Our working hypothesis posits that claustrum neural activity contributes to the acquisition, consolidation and reconsolidation of long-term memories in mice. We found evidence in CF-1 mice of a decline in behavioral performance in an inhibitory avoidance task due to intra-claustral administration of 2% lidocaine immediately after a training session or memory recall. Nevertheless, this does not seem to be the case for the acquisition or retrieval of this type of memory, although its neural activity is significantly increased after training, evaluated through c-Fos expression. Moreover, inhibition of the claustrum’s synaptic activity appears to impair the consolidation but not acquisition or retrieval of an unconditioned memory formed in a nose-poke habituation task.

A hypothalamic circuit mechanism underlying the impact of stress on memory and sleep.

Stress profoundly affects sleep and memory processes. Stress impairs memory consolidation, and similarly, disruptions in sleep compromise memory functions. Yet, the neural circuits underlying stress-induced sleep and memory disturbances are still not fully understood. Here, we show that activation of CRH PVN neurons, similar to acute restraint stress, decreases sleep and impairs memory in a spatial object recognition task. Conversely, inhibiting CRH PVN neurons during stress reverses stress-induced memory deficits while slightly increasing the amount of sleep. We found that both stress and stimulation of CRH PVN neurons activate neurons in the lateral hypothalamus (LH), and that their projections to the LH are critical for mediating stress-induced memory deficits and sleep disruptions. Our results suggest a pivotal role for CRH PVN neuronal pathways in regulating the adverse effects of stress on memory and sleep, an important step towards improving sleep and ameliorating the cognitive deficits that occur in stress-related disorders.

Ghrelin Modulates Voltage-Gated Ca2+ Channels through Voltage-Dependent and Voltage-Independent Pathways in Rat Gastric Vagal Afferent Neurons.

The orexigenic gut peptide ghrelin is an endogenous ligand for the growth hormone secretagogue receptor type 1a (GHSR1a). Systemic ghrelin administration has previously been shown to increase gastric motility and emptying. While these effects are known to be mediated by the vagus nerve, the cellular mechanism underlying these effects remains unclear. Therefore, the purpose of the present study was to investigate the signaling mechanism by which GHSR1a inhibits voltage-gated Ca2+ channels in isolated rat gastric vagal afferent neurons using whole-cell patch-clamp electrophysiology. The ghrelin pharmacological profile indicated that Ca2+ currents were inhibited with a log (Ic50) = -2.10 ± 0.44 and a maximal inhibition of 42.8 ± 5.0%. Exposure to the GHSR1a receptor antagonist (D-Lys3)-GHRP-6 reduced ghrelin-mediated Ca2+ channel inhibition (29.4 ± 16.7% vs. 1.9 ± 2.5%, n = 6, P = 0.0064). Interestingly, we observed that activation of GHSR1a inhibited Ca2+ currents through both voltage-dependent and voltage-independent pathways. We also treated the gastric neurons with either pertussis toxin (PTX) or YM-254890 to examine whether the Ca2+ current inhibition was mediated by the Gα i/o or Gα q/11 family of subunits. Treatment with both PTX (Ca2+ current inhibition = 15.7 ± 10.6%, n = 8, P = 0.0327) and YM-254890 (15.2 ± 11.9%, n = 8, P = 0.0269) blocked ghrelin's effects on Ca2+ currents, as compared with control neurons (34.3 ± 18.9%, n = 8). These results indicate GHSR1a can couple to both Gα i/o and Gα q/11 in gastric vagal afferent neurons. Overall, our findings suggest GHSR1a-mediated inhibition of Ca2+ currents occurs through two distinct pathways, offering necessary insights into the cellular mechanisms underlying ghrelin's regulation of gastric vagal afferents. SIGNIFICANCE STATEMENT: This study demonstrated that in gastric vagal afferent neurons, activation of GHSR1a by ghrelin inhibits voltage-gated Ca2+ channels through both voltage-dependent and voltage-independent signaling pathways. These results provide necessary insights into the cellular mechanism underlying ghrelin regulation of gastric vagal afferent activity, which may benefit future studies investigating ghrelin mimetics to treat gastric motility disorders.

The clinical and genetic spectrum of paediatric speech and language disorders.

Speech and language disorders are known to have a substantial genetic contribution. Although frequently examined as components of other conditions, research on the genetic basis of linguistic differences as separate phenotypic subgroups has been limited so far. Here, we performed an in-depth characterization of speech and language disorders in 52 143 individuals, reconstructing clinical histories using a large-scale data-mining approach of the electronic medical records from an entire large paediatric healthcare network. The reported frequency of these disorders was the highest between 2 and 5 years old and spanned a spectrum of 26 broad speech and language diagnoses. We used natural language processing to assess the degree to which clinical diagnoses in full-text notes were reflected in ICD-10 diagnosis codes. We found that aphasia and speech apraxia could be retrieved easily through ICD-10 diagnosis codes, whereas stuttering as a speech phenotype was coded in only 12% of individuals through appropriate ICD-10 codes. We found significant comorbidity of speech and language disorders in neurodevelopmental conditions (30.31%) and, to a lesser degree, with epilepsies (6.07%) and movement disorders (2.05%). The most common genetic disorders retrievable in our analysis of electronic medical records were STXBP1 (n = 21), PTEN (n = 20) and CACNA1A (n = 18). When assessing associations of genetic diagnoses with specific linguistic phenotypes, we observed associations of STXBP1 and aphasia (P = 8.57 × 10-7, 95% confidence interval = 18.62-130.39) and MYO7A with speech and language development delay attributable to hearing loss (P = 1.24 × 10-5, 95% confidence interval = 17.46-infinity). Finally, in a sub-cohort of 726 individuals with whole-exome sequencing data, we identified an enrichment of rare variants in neuronal receptor pathways, in addition to associations of UQCRC1 and KIF17 with expressive aphasia, MROH8 and BCHE with poor speech, and USP37, SLC22A9 and UMODL1 with aphasia. In summary, our study outlines the landscape of paediatric speech and language disorders, confirming the phenotypic complexity of linguistic traits and novel genotype-phenotype associations. Subgroups of paediatric speech and language disorders differ significantly with respect to the composition of monogenic aetiologies.

From microbes to mind: germ-free models in neuropsychiatric research.

The gut-microbiota-brain axis refers to the bidirectional communication system between the gut, its microbial community, and the brain. This interaction involves a complex interplay of neural pathways, chemical transmitters, and immunological mechanisms. Germ-free animal models have been extensively employed to investigate gut-microbiota-brain interactions, significantly contributing to our current understanding of the role of intestinal microbes in brain function. However, despite the many benefits, this absence of microbiota is not futile. Germ-free animals present physiological and neurodevelopmental alterations that can persist even after reconstitution with normal microbiota. Therefore, the main goal of this minireview is to discuss how some of the inherent limitations of this model can interfere with the conclusion obtained when using these animals to study the complex nature of neuropsychiatric disorders. Furthermore, we examine the inclusion and use of antibiotic-based treatments as an alternative in the research of gut-brain interactions.

Integrated transcriptomics and untargeted metabolomics reveal bone development and metabolism of newly weaned mice in response to dietary calcium and boron levels.

Epidemiological and animal studies have indicated that calcium and boron are essential for bone development and metabolism. However, limited information is available regarding the effects of boron supplementation on bone development and metabolism in newly weaned infants with either calcium deficiency or calcium sufficiency. This study assessed the effects of dietary boron supplementation (0 and 3 mg kg-1) on bone development and metabolism, in a newly weaned mouse model, under both calcium deficiency and sufficiency feeding conditions. The results show that mice fed a calcium sufficient diet exhibited lower fat percentage and final body weight than those fed a calcium deficient diet. Boron supplementation reduced the serum high-density lipoprotein cholesterol level and up-regulated the mRNA levels of FABP3, PPAR-γ, and CaMK in the intestinal mucosa. Importantly, boron supplementation increased the tibial weight in mice on a calcium-sufficient diet and enhanced the tibial volume in those on a calcium-deficient diet. Metabolomic analysis highlighted calcium and boron's impact on metabolites like carboxylic acids and derivatives, fatty acyls, steroids and steroid derivatives, benzene and substituted derivatives, organonitrogen compounds, organooxygen compounds, and phenols, and were related to lipid metabolism and the neural signaling pathway. Transcriptomic analysis corroborated the role of calcium and boron in modulating bone metabolism via the JAK-STAT, calcium signaling, lipid metabolism, and inflammatory pathways. Multi-omics analysis indicated a strong correlation between calcium signaling pathways, lipid metabolism signaling, and dietary calcium and boron contents. This research provides insights into these complex mechanisms, potentially paving the way for novel interventions against calcium and boron deficiencies and bone metabolism abnormalities in clinical settings.

Genetic architectures of the human hippocampus and those involved in neuropsychiatric traits

BackgroundThe hippocampus, with its complex subfields, is linked to numerous neuropsychiatric traits. While most research has focused on its global structure or a few specific subfields, a comprehensive analysis of hippocampal substructures and their genetic correlations across a wide range of neuropsychiatric traits remains underexplored. Given the hippocampus’s high heritability, considering hippocampal and subfield volumes (HASV) as endophenotypes for neuropsychiatric conditions is essential.MethodsWe analyzed MRI-derived volumetric data of hippocampal and subfield structures from 41,525 UK Biobank participants. Genome-wide association studies (GWAS) on 24 HASV traits were conducted, followed by genetic correlation, overlap, and Mendelian randomization (MR) analyses with 10 common neuropsychiatric traits. Polygenic risk scores (PRS) based on HASV traits were also evaluated for predicting these traits.ResultsOur analysis identified 352 independent genetic variants surpassing a significance threshold of 2.1 × 10−9 within the 24 HASV traits, located across 93 chromosomal regions. Notably, the regions 12q14.3, 17q21.31, 12q24.22, 6q21, 9q33.1, 6q25.1, and 2q24.2 were found to influence multiple HASVs. Gene set analysis revealed enrichment of neural differentiation and signaling pathways, as well as protein binding and degradation. Of 240 HASV-neuropsychiatric trait pairs, 75 demonstrated significant genetic correlations (P < 0.05/240), revealing 433 pleiotropic loci. Particularly, genes like ACBD4, ARHGAP27, KANSL1, MAPT, ARL17A, and ARL17B were involved in over 50 HASV-neuropsychiatric pairs. Leveraging Mendelian randomization analysis, we further confirmed that atrophy in the left hippocampus, right hippocampus, right hippocampal body, and right CA1-3 region were associated with an increased risk of developing Parkinson’s disease (PD). Furthermore, PRS for all four HASVs were significantly linked to a higher risk of Parkinson’s disease (PD), with the highest hazard ratio (HR) of 1.30 (95% CI 1.18–1.43, P = 6.15 × 10⁻⁸) for right hippocampal volume.ConclusionsThese findings highlight the extensive distribution of pleiotropic genetic determinants between HASVs and neuropsychiatric traits. Moreover, they suggest a significant potential for effectively managing and intervening in these diseases during their early stages.

MiR-27 and MiR-145 mediate neural differentiation signaling pathways in dental pulp stem cells

MiR-27 and MiR-145 mediate neural differentiation signaling pathways in dental pulp stem cells

Phlebotomy-induced anemia reduces oxygen-induced retinopathy severity and dampens retinal developmental transcriptomic pathways in rats.

Phlebotomy-induced-anemia (PIA), which induces tissue hypoxia and angiogenesis, occurs universally among infants at risk for severe retinopathy of prematurity (ROP). We hypothesized that PIA exacerbates pathologic retinal neovascularization in ROP. We induced PIA to a hematocrit of 18% among rats undergoing the established 50/10 oxygen-induced retinopathy (OIR) model. Rats were euthanized at P15 and P20, during the avascular and neovascular phases of OIR, respectively. Retinal vascular morphometry, cytokine/chemokine concentrations, transcriptomes, and mRNA expression of angiogenic and iron-deficiency markers were compared to non-PIA controls. In OIR, PIA decreased percent avascular area at P15 by 35%, percent neovascular area at P20 by 42%, and select pro-inflammatory cytokine/chemokine concentrations at both time points. At P20, PIA increased mRNA expression of angiopoietin 2/ vascular endothelial growth factor-A 2-fold and transferrin and transferrin receptor 5-fold. RNA sequencing showed dampened pathways of angiogenesis, inflammation, and neural development in anemic OIR females. Contrary to our hypothesis, PIA decreased OIR severity and retinal cytokine and chemokine levels and dampened transcriptomic pathways central to retinal vascular and neural development in neonatal rats. These data suggest PIA provides a protective effect from OIR. Further investigation into the functional effect of these molecular changes is warranted. This is the first preclinical study to investigate the impact of neonatal anemia on oxygen-induced retinopathy (OIR) outcomes. This study adds to the literature that anemia decreases neovascularization, decreases cytokine and chemokine levels, and dampens angiogenic and neural transcriptomic pathways in the rat 50/10 OIR model. The study identifies a sex-specific transcriptomic response to anemia in the 50/10 OIR model, with females primarily impacted.

Effect of Stellate Ganglion Block on Dysphagia and Cognitive Impairment in Cerebral Small Vessel Disease: A Randomized Controlled Study.

Cerebral small vessel disease (CSVD) can potentially and frequently lead to dysphagia and cognitive impairment. Stellate ganglion block (SGB) can alleviate the symptoms by regulating neural pathways and improving cerebral blood circulation. This study aimed to explore the clinical effect of SGB on airway protection, dysphagia, cognitive impairment, and activities of daily living (ADL) in CSVD patients. This was a randomized controlled study conducted from February 2021 to May 2023, including 84 CSVD patients with dysphagia and cognitive impairment. The participants were randomly divided into the SGB group (n = 42) and the untreated group (n = 42). All received standard-of-care rehabilitation for 20 days. The SGB group received SGB once a day additionally. Assessments were conducted on Day 1 and Day 20, respectively. The Penetration-Aspiration Scale (PAS) was primary outcome. Modified Barium Swallow Impairment (MBSImp), Mini-Mental State Examination (MMSE), Modified Barthel Index (MBI) and adverse events were secondary outcomes. This study was registered at ClinicalTrials.gov, Identifier: NCT06176404. There were two dropout cases in the untreated group. Time effect with statistical significance was observed in all assessments (p < .05). Group effect with statistical significance was observed in the PAS (z = -17.283, p < .001), MBSImp-Oral (z = -3.382, p = .001), MBSImp-Pharyngeal (z = -2.639, p = .008), MMSE (F = 7.450, p = .008), and MBI (F = 6.408, p = .013). During the treatment, there were no severe adverse events. SGB can significantly and safely improve airway protection, dysphagia, cognitive function, and ADL in CSVD patients with dysphagia and cognitive impairment who received standard-of-care rehabilitation.

Is It Possible to Regenerate the Underactive Detrusor? Part 1 Molecular and Stem Cell Therapies Targeting the Urinary Bladder and Neural Axis ICI-RS 2024.

Detrusor muscle weakness is commonly noted on urodynamics in patients with refractory voiding difficulty. No approved therapies have been proven to augment the strength of a detrusor voiding contraction. This subject was discussed by a think-tank at the International Consultation on Incontinence- Research Society (ICI-RS) meeting held in Bristol, June 2024. The discussions of the think-tank are being published in two parts. This first part discusses molecular and stem cell therapies targeting the urinary bladder and the neural axis. Senescence of the urothelium and extracellular ATP acting through P2X3 receptors might be important in detrusor underactivity. Several molecules such as parasympathomimetics, acotiamide, ASP8302, neurokinin-2 agonists have been explored but none has shown unequivocal clinical benefit. Different stem cell therapy approaches have been used, chiefly in neurogenic dysfunction, with some studies showing benefit. Molecular targets for the neural axis have included TRPV-4, Bombesin, and serotoninergic receptors and TAC-302 which induces neurite growth. Several options are currently being pursued in the search for an elusive molecular or stem cell option for enhancing the power of the detrusor muscle. These encompass a wide range of approaches that target each aspect of the contraction mechanism including the urothelium of bladder and urethra, myocyte, and neural pathways. While none of these have shown unequivocal clinical utility, some appear promising. Lessons from other fields of medicine might prove instructive. Not necessary. Not a clinical trial.

Therapies Using Anti-Diabetics to Prevent and Manage Progression of Parkinson's Disease

&lt;p&gt;Currently, a significant proportion of older individuals have demonstrated connections between Parkinson's disease (PD) and type 2 diabetes mellitus (T2DM). Emerging evidence from cohort studies, clinical data, and preclinical meta-analyses reveals that T2DM patients have an increased risk of developing PD, often accompanied by more severe disease progression. These two chronic conditions are believed to share common pathways. The pathways that likely connect the neurodegenerative process of PD include autophagy, mitochondrial dysfunction, dysregulated insulin signaling, inflammation, and insulin resistance. Preclinical PD models highlight the importance of cerebral insulin signaling, which confers numerous neuroprotective benefits. Several ongoing phase II and phase III trials are being conducted in PD-affected populations. These trials reflect the potential of existing anti-diabetic medications to improve PD motor symptoms and halt the progression of neurodegeneration. Brain insulin resistance plays a crucial role in the pathophysiology of PD. The insulin signaling pathway represents a promising novel target for disease modification in both diabetic and non-diabetic PD. Incretin receptors in the brain have emerged as the most promising targets for repurposing existing drugs in PD treatment. Targeting these receptors mitigates inflammation, apoptosis, toxic protein aggregation, long-term potentiation, autophagy, and insulin signaling failure. &lt;/p&gt;&lt;p&gt; Presently, various novel anti-diabetic targets are available that can regulate the insulin signaling pathway in dopaminergic neurons, suggesting improvements in cognitive function and significant neuroprotective effects in PD. Throughout neurodegenerative processes, insulin and incretins exert therapeutic effects in multiple manners. Preclinical studies have demonstrated that glucagon-- like peptide 1 (GLP-1) receptor agonists reduce neuroinflammation, tau phosphorylation, and amyloid deposition while increasing synaptic function and enhancing memory formation. Incretin mimetics may act through the restoration of insulin signaling pathways, inducing further neuroprotective effects. &lt;/p&gt;&lt;p&gt; This review examined the reported shared cellular and molecular pathologies between PD and T2DM, and explored the repurposing of anti-diabetic drugs for the prevention of PD progression through the regulation of insulin signaling pathways.&lt;/p&gt;

Hippotherapy As An Effective Treatment Strategy For Paediatric Population With Disabilities - A Literature Review

Background: Hippotherapy is an equine-assisted therapeutic method for the development of physical, occupational, and emotional performance in people suffering from various maladies. The neurophysiology of hippotherapy is characterized by the cyclical rhythmic movement of the horses, which is a kind of sensory input providing the rider with the information needed to maintain the proprioceptive and vestibular systems. It is the act of falling and jumping process that encourages neural pathways responsible for the development of the motor system which gradually results in the development of balance and coordination. To wit, the motion of those animals is one such that they imitate the normal human body’s walking pattern and in effect, like physiotherapy, they provide familiarity and thereby help in reskilling the rider’s core muscles and postural alignment. Furthermore, the relationship between the horse and the human being can also contribute to the emotional and spiritual side of the human being, thus, resulting in a more holistic approach to therapy that could be shown in practice through such modes as horse therapy. Methodology: We performed literature searching multiple electronic databases. The searches generated 50 potentially relevant studies. After applying inclusion and exclusion criteria, eliminating repeated articles, and critically evaluating the obtained results, nine papers were selected for the analysis. The selected papers were published between the period of January 2019 to July 2024. This comprised two cross-sectional studies, one experimental study, one exploratory study, one randomized controlled trial, and one survey investigation. Results: This literature review noticed a connection between hippotherapy and observable improvements in balance, coordination, gait, motor functions, cognitive functions, flexibility, functional mobility in children with disabilities. Conclusion: Hippotherapy has benefited balance, coordination, gait, motor functions, cognitive functions, flexibility, and functional mobility in children with disabilities, and thus, it should be considered as a treatment strategy for treating children with disabilities.

12509 Identification Of Novel Exercise Training-induced Circulating Proteins: Hemostatic, Apoptotic, And Key Neuronal Factors

Abstract Disclosure: A. Shalit: None. M. Vamvini: None. P. Nigro: None. L.K. Simpson: None. H. Pan: None. J.M. Dreyfuss: None. L.J. Goodyear: Grant Recipient; Self; Daiichi Sankyo. R.J. Middelbeek: None. Exercise training induces a plethora of health benefits including improved glucose homeostasis, decreased cardiovascular disease, and improved cognitive function. An emerging concept is that many of these beneficial effects of exercise are mediated through the secretion of humoral factors into the blood. Identification of these exercise-regulated factors hold promise for novel treatments for disease. Here, we performed proteomic analysis to discover novel circulating factors in response to endurance exercise training in human participants. Given that nutritional status can affect the circulating proteome, another aim was to determine if proteomic adaptations to exercise training have similar effects under both fasted and random-fed conditions. Sedentary normoglycemic participants (3M/5F, age 22-41y) performed a supervised 10-week exercise training program, which by week 4 was 4x60 min exercise at 65-70% V̇O2peak. Fasted and random-sampling morning blood draws were collected pre-training and between 24-72 hours following the final training session. Proteomic detection was by SOMAscan. Exercise training significantly improved V̇O2peak by 17% (p=0.003). Out of 1,310 detected proteins, exercise training significantly changed 293 proteins in the fasted state and 360 proteins in the random-sampling state (p&amp;lt;0.05). Integration showed that 172 proteins were changed under both nutritional conditions (123 upregulated and 49 downregulated). Gene Set Enrichment Analysis (GSEA) of the commonly upregulated proteins showed that training resulted in enrichment in neuronal, hemostatic, and apoptotic pathways, whereas the downregulated proteins were enriched in neuronal and extracellular matrix processes. Since neuronal pathways were identified in both up and downregulated proteins, we focused our analysis there, identifying 31 upregulated and 4 downregulated neuronally-associated proteins. Importantly, exercise training reduced levels of CDK5, a protein that is hyperactivated in neurodegeneration and Alzheimer's disease. Moreover, GSTP1, a direct inhibitor of CDK5, along with downstream proteins inhibited by CDK5 (RAC1, STUB1, 14-3-3ε/YWHAE, HSP90AA1, CFL1), were significantly increased following exercise training.In conclusion, exercise training regulates circulating factors involved in neuronal, hemostatic, apoptotic, and extracellular matrix pathways, with these effects being independent of nutritional status. Our finding of exercise training-induced decreases in multiple proteins of the CDK5 pathway, a pathway whose downregulation is associated with neuroprotection, identify CDK5 as a novel and potentially important mediator of the beneficial effects of exercise training on cognitive function. Presentation: 6/1/2024

12502 Bdnf Production by Kiss1 Neurons Acts in a Sexually Dependent Way to Control Sexual Development and Energy Balance in Female and Male Mice

Abstract Disclosure: A.M. Zanesco: None. D. Cabral: None. J. Ferreira: None. F. Valdivieso-Rivera: None. A.L. Carvalho: None. N. Mendes: None. C. Sponton: None. R. Frazao: None. L.A. Velloso: None. The hypothalamus is a key region in the central nervous system that controls different functions such as energy balance, thermogenesis, and reproduction. Kiss1 neurons integrate two distinct neuronal pathways, reproduction, and energy balance, both essential to species survival and maintenance. Recent studies, identify that the Brain-derived neurotrophic factor, BDNF produced by neurons and astrocytes in the hypothalamus is essential to control homeostatic and hedonic feeding by acting in specific groups of hypothalamic neurons. No studies showed the action of BDNF produced in the arcuate nucleus (ARC) of the hypothalamus. Using single-cell RNA sequencing analysis of data obtained from mice hypothalamus reveals that Kiss1 neurons express BDNF and we confirmed this result by immunofluorescence assay. Curiously, there is more expression of BDNF in the female hypothalamus compared with the male hypothalamus. But, when we selected specifically the BDNF produced by KISS1 neurons, this difference disappears. Based on that, we used a Cre-loxP approach to selectively knockout BDNF in Kiss1 neurons and identify the changes in sexual development and energy balance in female and male mice. All experiments were approved by the Animal Use Ethics Committee of UNICAMP (CEUA: 5591-1/2020 and CIBio 04/2021). All female and male mice were evaluated daily to identify their sexual development. We identified no changes in metabolic parameters, such as body weight and adiposity in male and female mice fed on a chow diet. Additionally, BDNF ablation in Kiss1 neurons (BDNF-KO) leaded to a premature vaginal opening, a decreased in uterus and ovary weight, and compromises the regular cyclicity of the estrus cycle in females. No difference was found in the sexual development of male mice, indicating that this effect is sexually dependent. Based on the fact that BDNF produced in VMH and DMH acts as anorexigenic effects, and Kiss1 neurons integrate the neuronal pathway responsible for energy balance, we decided to investigate the effects of BDNF ablation in Kiss1 neurons in female and male mice fed on high-fat diet. Interestingly, male mice without BDNF production in Kiss neurons were protected from obesity development compared with wild-type mice, both fed on a high-fat diet. When they were fed on a chow diet, male BDNF-KO mice, exhibited hyperphagia compared to control mice, showing a disruption in control of food intake and body weight maintenance. No differences were identified in body weight gain, food intake, and adiposity in BDNF-KO female mice. Based on that, we conclude that BDNF produced by Kiss1 exerts different functions in male and female mice. In females, it is more related to sexual development, and males in control of energy balance. This is the first research showing the BDNF production by Kiss1 neurons and its dimorphism effects on male and female mice. Presentation: 6/2/2024

Apache is a neuronal player in autophagy required for retrograde axonal transport of autophagosomes

Neurons are dependent on efficient quality control mechanisms to maintain cellular homeostasis and function due to their polarization and long-life span. Autophagy is a lysosomal degradative pathway that provides nutrients during starvation and recycles damaged and/or aged proteins and organelles. In neurons, autophagosomes constitutively form in distal axons and at synapses and are trafficked retrogradely to the cell soma to fuse with lysosomes for cargo degradation. How the neuronal autophagy pathway is organized and controlled remains poorly understood. Several presynaptic endocytic proteins have been shown to regulate both synaptic vesicle recycling and autophagy. Here, by combining electron, fluorescence, and live imaging microscopy with biochemical analysis, we show that the neuron-specific protein APache, a presynaptic AP-2 interactor, functions in neurons as an important player in the autophagy process, regulating the retrograde transport of autophagosomes. We found that APache colocalizes and co-traffics with autophagosomes in primary cortical neurons and that induction of autophagy by mTOR inhibition increases LC3 and APache protein levels at synaptic boutons. APache silencing causes a blockade of autophagic flux preventing the clearance of p62/SQSTM1, leading to a severe accumulation of autophagosomes and amphisomes at synaptic terminals and along neurites due to defective retrograde transport of TrkB-containing signaling amphisomes along the axons. Together, our data identify APache as a regulator of the autophagic cycle, potentially in cooperation with AP-2, and hypothesize that its dysfunctions contribute to the early synaptic impairments in neurodegenerative conditions associated with impaired autophagy.

Sex differences in the molecular profile of adult diffuse glioma are shaped by IDH status and tumor microenvironment.

Sex differences in adult diffuse glioma (ADG) are well-established clinically, yet the underlying molecular mechanisms remain inadequately understood. Here, we aim to reveal molecular features and cellular compositions unique to each sex in ADG to comprehend the role of sex in disease etiology. We quantified sex differences in transcriptome of ADG using multiple independent glioma patient datasets. Next, we delved into the single-cell landscape to examine sex differences in gene expression and cellular composition. To explore how sex influences disease progression, we analyzed paired samples from primary and recurrent ADG cases, aiming to identify sex-specific differences in molecular and cellular features. Our analysis revealed that mutations in isocitrate dehydrogenase (IDH) genes and the tumor microenvironment emerged as primary influencers of sex-differential molecular enrichments. In IDHwt tumors, genes in neuronal signaling pathway are found to be enriched in male tumors, while genes in hypoxia and inflammatory response pathways are enriched in female tumors. This pattern was reversed in IDHmut gliomas. We hypothesized that these distinctions could be attributed to heterogeneous cellular composition between sexes. Using single-cell data, we observed distinctive patterns of sex differences in cell states, cell composition and cell-cell interaction in IDHwt and IDHmut tumors separately. Further, by comparing molecular changes in paired primary and recurrent ADG samples, we identified sex-specific differences in molecular characteristics and cellular compositions of recurrent tumors. Our results provide a comprehensive multi-level characterization of sex differences in ADG, such findings provide novel insights into glioma disease progression in each sex.

Empathic pain: Underlying neural mechanism.

Empathy is usually regarded as the ability to perceive the emotional state of others, which is an altruistic motivation to promote prosocial behavior and thus plays a key role in human life and social development. Empathic pain-the capacity to feel and understand the pain of others-constitutes a significant aspect in the study of empathy behaviors. For an extended duration, investigations into empathic pain have predominantly centered on human neuroimaging studies. Fortunately, recent advancements have witnessed the utilization of animal models in the exploration of the fundamental neural underpinnings of empathic pain. There is substantial evidence implicating multiple brain regions and neural networks in the generation and maintenance of empathic pain. Nevertheless, further elucidation of the neural mechanisms underlying empathic pain is warranted. This review provides a concise overview of prior studies on the neural mechanisms of empathic pain, outlining the pertinent brain regions, neural pathways, synaptic mechanisms, and associated molecules while also delving into future prospects.

Neural pathways and computations that achieve stable contrast processing tuned to natural scenes

Natural scenes are highly dynamic, challenging the reliability of visual processing. Yet, humans and many animals perform accurate visual behaviors, whereas computer vision devices struggle with rapidly changing background luminance. How does animal vision achieve this? Here, we reveal the algorithms and mechanisms of rapid luminance gain control in Drosophila, resulting in stable visual processing. We identify specific transmedullary neurons as the site of luminance gain control, which pass this property to direction-selective cells. The circuitry further involves wide-field neurons, matching computational predictions that local spatial pooling drive optimal contrast processing in natural scenes when light conditions change rapidly. Experiments and theory argue that a spatially pooled luminance signal achieves luminance gain control via divisive normalization. This process relies on shunting inhibition using the glutamate-gated chloride channel GluClα. Our work describes how the fly robustly processes visual information in dynamically changing natural scenes, a common challenge of all visual systems.

The role of loss aversion in social conformity: psychological and neural representations.

The impact of others' choices on decision-making is influenced by individual preferences. However, the specific roles of individual preferences in social decision-making remain unclear. In this study, we examine the contributions of risk and loss preferences as well as social influence in decision-making under uncertainty using a gambling task. Our findings indicate that while both individual preferences and social influence affect decision-making in social contexts, loss aversion plays a dominant role, especially in individuals with high loss aversion. This phenomenon is accompanied by increased functional connectivity between the anterior insular cortex and the temporoparietal junction. These results highlight the critical involvement of loss aversion and the anterior insular cortex-temporoparietal junction neural pathway in social decision-making under uncertainty. Our findings provide a computational account of how individual preferences and social information collectively shape our social decision-making behaviors.