Baseline Activity Research Articles

Big data and its impact on the 3Rs: a home cage monitoring oriented review.

Undisturbed home cage recording of mouse activity and behavior has received increasing attention in recent years. In parallel, several technologies have been developed in a bid to automate data collection and interpretation. Thanks to these expanding technologies, massive datasets can be recorded and saved in the long term, providing a wealth of information concerning animal wellbeing, clinical status, baseline activity, and subsequent deviations in case of experimental interventions. Such large datasets can also serve as a long-term reservoir of scientific data that can be reanalyzed and repurposed upon need. In this review, we present how the impact of Big Data deriving from home cage monitoring (HCM) data acquisition, particularly through Digital Ventilated Cages (DVCs), can support the application of the 3Rs by enhancing Refinement, Reduction, and even Replacement of research in animals.

Sub-lethal effects of the insecticide, imidacloprid, on the responses of damselfly larvae to chemosensory cues indicating predation risk

Insecticides, including the widely used neonicotinoids, can affect both pest and non-target species. In addition to lethal effects, these insecticides at sub-lethal levels may cause disruption to sensory perception and processing leading to behavioural impairments. In this laboratory experiment, we investigated the effects of a 10-day exposure to the neonicotinoid insecticide, imidacloprid, on the behaviour of larvae of the damselfly, Lestes congener. In tests of baseline activity, imidacloprid concentrations of 1.0 and 10.0 μg/L caused significant reductions in foraging behaviour. Moreover, in response to chemical cues that indicate a potential risk to the larvae, imidacloprid caused the loss of an appropriate antipredator response (reduced foraging) depending on the concentration and duration of exposure. Imidacloprid at 0.1 μg/L caused the loss of responses toward the odour of a beetle (Dytiscus spp.) predator after 10 days of exposure, whereas 1.0 μg/L caused lost responses toward both the predator odour and injured conspecific cues (i.e., alarm cues) and after only 2 days of exposure. However, at 10.0 μg/L, larvae responded appropriately to both cues throughout the duration of the study, suggesting compensatory responses to imidacloprid at higher concentrations. Hence, the lack of appropriate responses at 1.0 μg/L likely resulted from a cognitive impairment rather than chemical alteration of these important chemosensory cues. In the natural environment, such effects will likely cause decreased survivorship in predator encounters. Hence, imidacloprid exposure, even at low concentrations, could have adverse consequences for chemosensory ecology of this damselfly species.

Clustering patients with late-life depression by blood glutathione-dependent enzymatic activities for stratification of a heterogeneous group

IntroductionWe have previously found significant alterations in activities of glutathione dependent enzymes in blood cells of patients with late-life depression (LLD) compared with age-matched controls.ObjectivesThe revealing subgroups of LLD patients by glutathione-metabolism enzymes’ activities in blood cells using cluster analysis.Methods LLD patients (n=101) of 60-86 age (69 patients with recurrent depression (RD), 23 with bipolar disorder (BD) and 9 patients with a single depressive episode (DE)) were assessed by Hamilton depression rating scale (HAMD-17), and Hamilton Anxiety Rating Scale (HARS). Activity levels of glutathione reductase (GR) and glutathione S-transferase (GST) were determined in patients’ platelets (-pl) and erythrocytes (-er). The control group consisted of 51 peoples 55-84 years old without mental pathology. Cluster analysis module of the STATISTICA software was used for clustering the patients by baseline blood parameters.Results Three clusters of patients were obtained: C1, n=39, C2, n=31, C3, n=31, differing significantly in all biochemical parameters (Kruskal-Wallis test, p<0.001), except GST. When compared with control group by Mann-Whitney test, GST-pl, GST-er, and GR-er were significantly decreased in C1; GST-er was significantly increased in C2; GST-pl, GR-pl, and GR-er were significantly decreased in C3. Several significant correlations were found between the measured parameters and scores by HDRS or HAMD-17. In C1, baseline activity of GST-er correlated with total scores by HAMD-17 (R=0.335, p=0.043) after treatment. In C2, baseline activity of GR-er correlated with total scores by HARS (R=-0.376, p=0,037) after treatment and GR-pl correlated with delta scores by HAMD-17 under the treatment (R=0.484, p=0.006). No significant correlations were found in C3. Patients with BD distributed significantly unevenly between C1, C2, and C3, with significantly more BD patients clustering in C1 (61%) compared with C2 and C3 (Yetes-corrected Chi-square =7.73, p=0.0054), whereas patients with RD and DE distributed evenly.Conclusions Patterns of activity levels for glutathione-dependent enzymes in patients with BD differ from those in patients with RD and DE. Significant correlations of the measured biochemical parameters with scores by HDRS or HAMD-17 assessed after the treatment and evidenced for the treatment efficacy seem to be promising biomarkers for further evaluation of the treatment efficacy in heterogeneous group of LLD patients using the proposed approach to their stratification into subgroups.Disclosure of InterestNone Declared

Functional evaluation of a novel nonsense variant of the calcium-sensing receptor gene leading to hypocalcemia.

The calcium-sensing receptor (CASR) gene encodes a G protein-coupled receptor crucial for calcium homeostasis. Gain-of-function CASR variants result in hypocalcemia, while loss-of-function variants lead to hypercalcemia. This study aims to assess the functional consequences of the novel nonsense CASR variant [c.2897_2898insCTGA, p.(Gln967*) (Q967*)] identified in adolescent patient with chronic hypocalcemia, a phenotype expected for a gain-of-function variants. To functionally characterize the Q967* mutant receptor, both wild-type (WT) and mutant CASR were transiently transfected into HEK293T cells and calcium-sensing receptor (CaSR) protein expression and functions were comparatively evaluated using multiple read-outs. Western blot analysis revealed that the CaSR mutant protein displayed a lower molecular weight compared with the WT, consistent with the loss of the last 122 amino acids in the intracellular domain. Mitogen-activated protein kinase activation and serum responsive element luciferase assays demonstrated that the mutant receptor had higher baseline activity than the WT. Extracellular-signal-regulated kinase/c-Jun N-terminal kinase phosphorylation, however, remained consistently high in the mutant, without significant modulations following exposure to increasing extracellular calcium (Ca2+o) levels, suggesting that the mutant receptor is more sensitive to Ca2+o compared with the WT. This study provides functional validation of the pathogenicity of a novel nonsense CASR variant, resulting in an abnormally hyperfunctioning protein consistent with the patient's phenotype. Functional analyses indicate that mutant receptor is constitutively active and poorly sensitive to increasing concentrations of extracellular calcium, suggesting that the cytoplasmic tail may contain elements regulating signal transduction.

Adaptation and learning as strategies to maximize reward in neurofeedback tasks.

Adaptation and learning have been observed to contribute to the acquisition of new motor skills and are used as strategies to cope with changing environments. However, it is hard to determine the relative contribution of each when executing goal directed motor tasks. This study explores the dynamics of neural activity during a center-out reaching task with continuous visual feedback under the influence of rotational perturbations. Results for a brain-computer interface (BCI) task performed by two non-human primate (NHP) subjects are compared to simulations from a reinforcement learning agent performing an analogous task. We characterized baseline activity and compared it to the activity after rotational perturbations of different magnitudes were introduced. We employed principal component analysis (PCA) to analyze the spiking activity driving the cursor in the NHP BCI task as well as the activation of the neural network of the reinforcement learning agent. Our analyses reveal that both for the NHPs and the reinforcement learning agent, the task-relevant neural manifold is isomorphic with the task. However, for the NHPs the manifold is largely preserved for all rotational perturbations explored and adaptation of neural activity occurs within this manifold as rotations are compensated by reassignment of regions of the neural space in an angular pattern that cancels said rotations. In contrast, retraining the reinforcement learning agent to reach the targets after rotation results in substantial modifications of the underlying neural manifold. Our findings demonstrate that NHPs adapt their existing neural dynamic repertoire in a quantitatively precise manner to account for perturbations of different magnitudes and they do so in a way that obviates the need for extensive learning.

Amygdala real-time fMRI neurofeedback upregulation in treatment resistant depression: Proof of concept and dose determination

Previous work has shown that adults suffering from major depressive disorder (MDD) can increase their amygdala reactivity while recalling positive memories via real-time neurofeedback (rt-fMRI-nf) training, which is associated with reduction in depressive symptoms. This study investigated if this intervention could also be considered for patients suffering from MDD who do not respond to standard psychological and pharmacological interventions, i.e., treatment resistant (TR-MDD).15 participants received 5 neurofeedback sessions. Outcome measures were depressive symptoms assessed by BDI scores up to 12 weeks following acute intervention, and amygdala activity changes from initial baseline to final transfer run during neurofeedback sessions (neurofeedback success).Participants succeeded in increasing their amygdala activity. A main effect of visit on BDI scores indicated a significant reduction in depressive symptomatology. Percent signal change in the amygdala showed a learning curve during the first session only. Neurofeedback success computed by session was significantly positive only during the second session. When examining the baseline amygdala response, baseline activity stabilized/asymptoted by session 3.This proof-of-concept study suggests that only two neurofeedback sessions are necessary to enable those patients to upregulate their amygdala activity, warranting a future RCT. Over the course of the rtfMRI-nf intervention, participants also reported reduced depressive symptomatology.Clinical trial registration number: NCT03428828 on ClinicalTrials.gov.

Social buffering in rats reduces fear by oxytocin triggering sustained changes in central amygdala neuronal activity

The presence of a companion can reduce fear, but the neural mechanisms underlying this social buffering of fear are incompletely known. We studied social buffering of fear in male and female, and its encoding in the amygdala of male, auditory fear-conditioned rats. Pharmacological, opto,- and/or chemogenetic interventions showed that oxytocin signaling from hypothalamus-to-central amygdala projections underlied fear reduction acutely with a companion and social buffering retention 24 h later without a companion. Single-unit recordings with optetrodes in the central amygdala revealed fear-encoding neurons (showing increased conditioned stimulus-responses after fear conditioning) inhibited by social buffering and blue light-stimulated oxytocinergic hypothalamic projections. Other central amygdala neurons showed baseline activity enhanced by blue light and companion exposure, with increased conditioned stimulus responses that persisted without the companion. Social buffering of fear thus switches the conditioned stimulus from encoding “fear” to “safety” by oxytocin-mediated recruitment of a distinct group of central amygdala “buffer neurons”.

Insights into Gastrointestinal Redox Dysregulation in a Rat Model of Alzheimer's Disease and the Assessment of the Protective Potential of D-Galactose.

Recent evidence suggests that the gut plays a vital role in the development and progression of Alzheimer's disease (AD) by triggering systemic inflammation and oxidative stress. The well-established rat model of AD, induced by intracerebroventricular administration of streptozotocin (STZ-icv), provides valuable insights into the GI implications of neurodegeneration. Notably, this model leads to pathophysiological changes in the gut, including redox dyshomeostasis, resulting from central neuropathology. Our study aimed to investigate the mechanisms underlying gut redox dyshomeostasis and assess the effects of D-galactose, which is known to benefit gut redox homeostasis and alleviate cognitive deficits in this model. Duodenal rings isolated from STZ-icv animals and control groups were subjected to a prooxidative environment using 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) or H2O2 with or without D-galactose in oxygenated Krebs buffer ex vivo. Redox homeostasis was analyzed through protein microarrays and functional biochemical assays alongside cell survival assessment. Structural equation modeling and univariate and multivariate models were employed to evaluate the differential response of STZ-icv and control samples to the controlled prooxidative challenge. STZ-icv samples showed suppressed expression of catalase and glutathione peroxidase 4 (GPX4) and increased baseline activity of enzymes involved in H2O2 and superoxide homeostasis. The altered redox homeostasis status was associated with an inability to respond to oxidative challenges and D-galactose. Conversely, the presence of D-galactose increased the antioxidant capacity, enhanced catalase and peroxidase activity, and upregulated superoxide dismutases in the control samples. STZ-icv-induced gut dysfunction is characterized by a diminished ability of the redox regulatory system to maintain long-term protection through the transcription of antioxidant response genes as well as compromised activation of enzymes responsible for immediate antioxidant defense. D-galactose can exert beneficial effects on gut redox homeostasis under physiological conditions.

Positive Affect and Physical Activity Associations in Women and Their Spouses.

Only 21% of U.S. women meet the recommended physical activity guidelines, placing them at increased risk for long-term conditions such as heart disease and diabetes. Physical activity is influenced by individual and interpersonal factors (e.g., romantic partners). Individual factors, such as positive affect, are associated with lower mortality risk and improved health behaviors. This secondary data analysis, guided by Fredrickson's Broaden and Build Theory, aims to examine the relationship between positive affect of married women (n = 115 couples) and their physical activity behavior on the same- and next- day, while also considering their spouses' positive affect. Two population average models assessed the relationship of calm and happy (positive affect) to physical activity. Physical activity was assessed as the sum of the minutes of moderate-to-vigorous physical activity (MVPA) over the prior 24 hours. Covariates of age, baseline activity frequency, education, marital quality, and race/ethnicity were also included. Women's happiness (β = 0.15, p < .005), not calmness (β = -0.03, p = .60), was found to have a significant association with same-day MVPA. Spouses' happiness (β = 0.11, p = .045) was significantly associated with women's next-day MVPA while their calmness (β = -0.04, p = .44) was not. The results of this study support that incorporating positive affect could be valuable for improving physical activity behaviors. Spouse reports provide additional context to consider in physical activity promotion research.

In vitro modulator responsiveness of 655 CFTR variants found in people with cystic fibrosis

BackgroundIn 2017, the US Food and Drug Administration initiated expansion of drug labels for the treatment of cystic fibrosis (CF) to include CF transmembrane conductance regulator (CFTR) gene variants based on in vitro functional studies. This study aims to identify CFTR variants that result in increased chloride (Cl−) transport function by the CFTR protein after treatment with the CFTR modulator combination elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA). These data may benefit people with CF (pwCF) who are not currently eligible for modulator therapies. MethodsPlasmid DNA encoding 655 CFTR variants and wild-type (WT) CFTR were transfected into Fisher Rat Thyroid cells that do not natively express CFTR. After 24 h of incubation with control or TEZ and ELX, and acute addition of IVA, CFTR function was assessed using the transepithelial current clamp conductance assay. Each variant's forskolin/cAMP-induced baseline Cl− transport activity, responsiveness to IVA alone, and responsiveness to the TEZ/ELX/IVA combination were measured in three different laboratories. Western blots were conducted to evaluate CFTR protein maturation and complement the functional data. Results and conclusions253 variants not currently approved for CFTR modulator therapy showed low baseline activity (<10 % of normal CFTR Cl− transport activity). For 152 of these variants, treatment with ELX/TEZ/IVA improved the Cl− transport activity by ≥10 % of normal CFTR function, which is suggestive of clinical benefit. ELX/TEZ/IVA increased CFTR function by ≥10 percentage points for an additional 140 unapproved variants with ≥10 % but <50 % of normal CFTR function at baseline. These findings significantly expand the number of rare CFTR variants for which ELX/TEZ/IVA treatment should result in clinical benefit.

Anatomical and physiological characteristics of claustrum neurons in primates and rodents

The claustrum, a structure having extensive connectivity with the rest of the brain and being involved in many high-cognitive processes, is still one of the least understood parts of the mammalian nervous system. Accelerated advancement of genetic tools for rodents in the last decade have resulted in many breakthroughs about its interaction with cortical and subcortical regions, while human/primate studies have been invaluable in revealing its effects on conscious behaviour. However, these findings did not elucidate conclusively the principles of its internal dynamics, which would clarify its function within the brain network. The first step in this direction is to know the characteristics of major types of neurons in the claustrum. In this review, we are looking at the data allowing a comparison between the main neuronal types of the claustrum in primates and rodents, with the aim of showing the extent of known commonalities and differences, and highlighting the research gap between the two orders. The results indicate that in both there is a ratio excitatory/inhibitory neurons higher than in the cortex, but with a lower baseline activity of the excitatory neurons due to the higher inhibition. The local excitation in the claustrum is provided by collaterals of neurons projecting to the cortex. Secondary neuronal markers such as Calcium binding proteins and somatostatin tend to be expressed differently in the claustrum of primates than in that of rodents, specifically in more classes of neurons and across a larger area. The spatial distribution of neuropeptide Y might be a conserved motif across the two orders. The work in rodents has an undisputable advance in the study of electrical properties for each class of claustrum neurons. However, for a deep understanding of the claustrum function in the human brain, primate studies remain indispensable.

Features of baseline and lipopolysaccharide-induced cytokine secretion in mononuclear leukocyte cultures from patients with the erythema migrans form of acute lyme borreliosis based on clinical parameters

Introduction. Features of cytokine production in mononuclear cell cultures from Lyme borreliosis patients based on clinical data remained poorly studied. The study aim was to estimate the patterns of baseline and lipopolysaccharide-induced cytokine-secretory activity of peripheral blood mononuclear leukocytes from patients with erythema migrans form of acute Lyme borreliosis based on clinical parameters. Materials and methods. Groups of 22 and 12 patients with the diagnoses of mild or moderate severity of monoinfection and co-infection with tick-borne encephalitis of Lyme borreliosis with erythema migrans were examined twice: on week 1 after disease onset and day 14. The control group included 17 healthy donors. Basal and lipopolysaccharide-induced IL-6, IL-10, and TNFα secretion levels were assessed in mononuclear leukocyte culture supernatants applying enzyme immunoassay. Statistical analysis was performed by using the Mann–Whitney U-test, Wilcoxon test, and Spearman’s rank correlation. Results. The group of moderate severity patients was clinically distinguished by severer fever and intoxication manifestations. At the disease onset, the basal TNFα, IL-6 and IL-10 secretion levels in the moderate severity patient cultures were significantly higher than in those of the other groups. After antibiotics treatment, the baseline TNFα and IL-10 levels tended to decrease. At the onset, lipopolysaccharide-induced cultures from the moderate severity patients showed significantly suppressed TNFα production and increased IL-10 secretion as compared to the other groups. Lipopolysaccharide-induced IL-6 secretion in the moderate vs. mild severity group supernatants was significantly lower. In dynamics, the induced TNFα levels in the moderate severity patients were increased to the magnitude exceeding that in the controls. Positive correlations between the IL-6 and TNFα basal levels and maximum body temperature or the C-reactive protein serum concentrations were revealed in the patients. Induced TNFα levels showed negative correlations with fever levels or with IL-10 secretion. Conclusions. It was demonstrated that basal TNFα, IL-6 and IL-10 secretion levels in the mononuclear cell cultures of acute Lyme borreliosis patients increased with the increasing disease severity. Suppression of lipopolysaccharide-induced TNFα production in the moderate severity patient cultures was presumably associated with the regulatory cytokine IL-10 effects.

P916 Off-label dose escalation of Ustekinumab in Inflammatory Bowel Disease patients. Incidence rate, timing, dosing patterns and outcomes

Abstract Background In patients with inflammatory bowel disease (IBD), after intravenous induction,Ustekinumab (UST) is administered as maintenance 90 mg every 8 (Q8) or 12 weeks (Q12) subcutaneously. As with other biological drugs, dose intensification may be effective after inadequate response or loss of response. However, different dosing regimens have been used and the best strategy is unknown. Our aim was to evaluate the incidence and efficacy of UST off-label dose escalation in IBD. Methods We performed an observational cohort study in 2 hospitals in Vigo,Spain. All patients who started UST between 1 June 2017 and 31 December 2022 to control their active IBD were enrolled. The primary endpoints were incidence rate and outcomes of UST off-label dose intensification. Secondary endpoints were the timing of dose escalation and the patterns indicated. Results 1 173 IBD patients received UST: females 53.8% (93), mean age 49.7(15.5) years, Crohn´s disease 82% (142), previous anti-TNF 93.6% (162) and vedolizumab 22.5% (39) (Table 1). Subcutaneous UST was maintained Q8 in 63.6% (110) and Q12 in 34.7% (60). Baseline activity data were higher in Q8 patients (p=0.001). At 16 week 23 patients (13.3%) had no response, but 9 (39.1%) became late responders at 6 months. Of the 173 IBD patients included, 38.2% and 30.6 % achieved clinical response and clinical remission at 1 year. Dose escalation was performed in 32.4% (56) with different patterns: 54.5% Q4 (30), 21.8% reinduction plus Q4 (12), 12.7% Q6 (7) and 10.9% only intravenous reinduction (6). The timing of dose escalation was: before 6 months in 19.6% (11), at 12 months 42.8% (24) and at 2 years 73.2% (41). Response and remission were achieved in 28.6% (16) and 41.1% (23) after dose escalation respectively. In 6.4% of the patients (11) a second dose escalation was indicated. Neither previous anti-TNF or vedolizumab nor concomitant use of steroids at starting UST were associated to dose escalation. IBD patients that were initially scheduled to receive subcutaneous UST Q12 needed less dosing escalation (p&amp;lt;0.001). Conclusion Off-label UST dose escalation was frequent and effective in achieving response in IBD patients. The schemes of dose-escalation were heterogeneous between the participants. Patients initially scheduled Q12 due to lower inflammatory activity required less dose escalation.

Delayed Ustekinumab and Adalimumab Responders Have Similar Outcomes as Early Responders in Biologic-Naïve Crohn's Disease.

Differences in 1-year outcomes among early and delayed responders have been demonstrated with some therapies in ulcerative colitis. However, it is unclear whether similar differences exist in patients with Crohn's disease (CD) treated with biologic therapies. This was a post hoc analysis of patient-level data from the SEAVUE clinical trial program. Ustekinumab-treated and adalimumab-treated patients with clinical response at week 8, defined as a reduction in Crohn's Disease Activity Index (CDAI) score of at least 100 points from baseline or CDAI score <150, were deemed early responders and their outcomes were compared with delayed responders (week 8 nonresponders who subsequently responded at week 16) and nonresponders (no response at week 8 or 16). The primary outcome assessed was clinical remission at week 56, defined as CDAI <150. A total of 373 participants (187 treated with ustekinumab and 186 treated with adalimumab) were included in this analysis. The overall rate of delayed clinical response was low in the SEAVUE clinical trial program (13.1%). No differences were observed for week 56 clinical remission among early vs delayed responders to ustekinumab or adalimumab nor were there significant differences for secondary outcomes assessed. Delayed responders to ustekinumab and adalimumab had a significant decline in C-reactive protein by week 8 when compared with nonresponders. Among patients with moderate-to-severe CD, early and delayed responders to adalimumab and ustekinumab have similar 1-year clinical outcomes. Biomarker decline can be observed through the initial 8 weeks of therapy in patients who will eventually be delayed responders, which may help differentiate from nonresponders.

Aberrant Cortical Activity in 5xFAD Mice in Response to Social and Non-Social Olfactory Stimuli.

Neuroimaging studies investigating the behavioral and psychological symptoms of dementia (BPSD)- such as apathy, anxiety, and depression- have linked some of these symptoms with altered neural activity. However, inconsistencies in operational definitions and rating scales, limited scope of assessments, and poor temporal resolution of imaging techniques have hampered human studies. Many transgenic (Tg) mouse models of Alzheimer's disease (AD) exhibit BPSD-like behaviors concomitant with AD-related neuropathology, allowing examination of how neural activity may relate to BPSD-like behaviors with high temporal and spatial resolution. To examine task-dependent neural activity in the medial prefrontal cortex (mPFC) of AD-model mice in response to social and non-social olfactory stimuli. We previously demonstrated age-related decreases in social investigation in Tg 5xFAD females, and this reduced social investigation is evident in Tg 5xFAD females and males by 6 months of age. In the present study, we examine local field potential (LFP) in the mPFC of awake, behaving 5xFAD females and males at 6 months of age during exposure to social and non-social odor stimuli in a novel olfactometer. Our results indicate that Tg 5xFAD mice exhibit aberrant baseline and task-dependent LFP activity in the mPFC- including higher relative delta (1-4 Hz) band power and lower relative power in higher bands, and overall stronger phase-amplitude coupling- compared to wild-type controls. These results are consistent with previous human and animal studies examining emotional processing, anxiety, fear behaviors, and stress responses, and suggest that Tg 5xFAD mice may exhibit altered arousal or anxiety.

MEF2C Hypofunction in GABAergic Cells Alters Sociability and Prefrontal Cortex Inhibitory Synaptic Transmission in a Sex-Dependent Manner

BackgroundHeterozygous mutations or deletions of MEF2C cause a neurodevelopmental disorder termed MEF2C haploinsufficiency syndrome (MCHS), characterized by autism spectrum disorder and neurological symptoms. In mice, global Mef2c heterozygosity has produced multiple MCHS-like phenotypes. MEF2C is highly expressed in multiple cell types of the developing brain, including GABAergic (gamma-aminobutyric acidergic) inhibitory neurons, but the influence of MEF2C hypofunction in GABAergic neurons on MCHS-like phenotypes remains unclear. MethodsWe employed GABAergic cell type–specific manipulations to study mouse Mef2c heterozygosity in a battery of MCHS-like behaviors. We also performed electroencephalography, single-cell transcriptomics, and patch-clamp electrophysiology and optogenetics to assess the impact of Mef2c haploinsufficiency on gene expression and prefrontal cortex microcircuits. ResultsMef2c heterozygosity in developing GABAergic cells produced female-specific deficits in social preference and altered approach-avoidance behavior. In female, but not male, mice, we observed that Mef2c heterozygosity in developing GABAergic cells produced 1) differentially expressed genes in multiple cell types, including parvalbumin-expressing GABAergic neurons, 2) baseline and social-related frontocortical network activity alterations, and 3) reductions in parvalbumin cell intrinsic excitability and inhibitory synaptic transmission onto deep-layer pyramidal neurons. ConclusionsMEF2C hypofunction in female, but not male, developing GABAergic cells is important for typical sociability and approach-avoidance behaviors and normal parvalbumin inhibitory neuron function in the prefrontal cortex of mice. While there is no apparent sex bias in autism spectrum disorder symptoms of MCHS, our findings suggest that GABAergic cell-specific dysfunction in females with MCHS may contribute disproportionately to sociability symptoms.

FREQUENCY SYNCHRONIZATION REVEALS THAT SPIKE-WAVE DISCHARGES IN WAG/RIJ RATS ARE SIGNIFICANTLY NONLINEAR PHENOMENON

In this work, we studied the time-frequency dynamics of spike-wave discharges in rats with predisposition to absence epilepsy (WAG/Rij line) in two frequency ranges: 7–12,Hz and 14–24,Hz. The first and the second harmonics of the seizure main frequency lie in these ranges. Recordings of brain local field potentials of eight animals in eleven experiments of eight hour duration were analyzed. The method was based on the fast Fourier transform with a Hann’s window, and skeletons were constructed based on the obtained spectrograms. Using the skeletons, a visual and automated numerical assessment of the main frequency evolution was performed. As a result of this analysis, it was shown that temporal dynamics of the main frequency in the range 14–24,Hz follows the dynamics of the main frequency in the range 7–12,Hz. Since during the baseline activity the main frequencies in two considered ranges were developing independently, our finding indicates that the discharge is a significantly nonlinear process.

N-acetylcysteine attenuates accumbal core neuronal activity in response to morphine in the reinstatement of morphine CPP in morphine extinguished rats

Numerous studies have suggested that N-acetylcysteine (NAC), has the potential to suppress drug craving in people with substance use disorder and reduce drug-seeking behaviors in animals. The nucleus accumbens (NAc) plays a crucial role in the brain's reward system, with the nucleus accumbens core (NAcore) specifically implicated in compulsive drug seeking and relapse. In this study, we aimed to explore the impact of subchronic NAC administration during the extinction period and acute NAC administration on the electrical activity of NAcore neurons in response to a priming dose of morphine in rats subjected to extinction from morphine-induced place preference (CPP).We conducted single-unit recordings in anesthetized rats on the reinstatement day, following the establishment of morphine-induced conditioned place preference (7 mg/kg, s.c., 3 days), and subsequent drug-free extinction. In the subchronically NAC-treated groups, rats received daily injections of either NAC (50 mg/kg; i.p.) or saline during the extinction period. On the reinstatement day, we recorded the spontaneous activity of NAcore neurons for 15 min, administered a priming dose of morphine, and continued recording for an additional 45 min. While morphine excited most recorded neurons in saline-treated rats, it failed to alter firing rates in NAC-treated rats that had received NAC during the extinction period. For acutely NAC-treated animals, we recorded the baseline activity of NAcore neurons for 10 min before administering a single injection of either NAC (50 mg/kg; i.p.) or saline in rats with no treatment during the extinction. Following 30 min of recording and a priming dose of morphine (1 mg/kg, s.c.), the recording continued for an additional 30 min. The firing activity of NAcore neurons did not show significant changes after morphine or NAC injection. In conclusion, our findings emphasize that daily NAC administration during the extinction period significantly attenuates the morphine-induced increase in firing rates of NAcore neurons during the reinstatement of morphine CPP. However, acute NAC injection does not produce the same effect. These results suggest that modulating glutamate transmission through daily NAC during extinction may effectively inhibit the morphine place preference following the excitatory effects of morphine on NAcore neurons.

CASL: Capturing Activity Semantics Through Location Information for Enhanced Activity Recognition.

Using portable tools to monitor and identify daily activities has increasingly become a focus of digital healthcare, especially for elderly care. One of the difficulties in this area is the excessive reliance on labeled activity data for corresponding recognition modeling. Labeled activity data is expensive to collect. To address this challenge, we propose an effective and robust semi-supervised active learning method, which combines the mainstream semi-supervised learning method with expert collaboration. Our method takes a user's trajectory as the only input. In addition, this novel method uses expert collaboration to judge the valuable samples further to enhance its performance. Our method relies on very few semantic activities, outperforms all baseline activity recognition methods, and is close to the performance of supervised learning methods. On the adlnormal dataset with 200 semantic activities data, our work achieved an accuracy of 89.07%, and supervised learning has 91.77%. Our ablation study validated the components in our method using a query strategy and a data fusion approach.

The relationship between [18F]FDG‐PET signal and key‐players of brain glucose metabolism

AbstractBackgroundNeuronal activity is supported by activity‐dependent lactate production from astrocytes, as postulated by the astrocyte–neuron lactate shuttle (ANLS) hypothesis. Indeed, astrocytic glutamate uptake is a main trigger for brain glucose consumption. [18F]fluorodeoxyglucose (FDG)‐PET showing a hypometabolic signature has been used as an index of neurodegeneration in Alzheimer’s disease (AD). In the early stages of the disease, soluble amyloid‐beta (Aβ) has been associated with neuronal hyperactivity due to decreased astrocytic glutamate uptake. It is hypothesized that this phenomenon occurs especially in regions with high ongoing baseline activity. Over time, neurodegeneration and hypometabolism in such regions may contribute to the progress of the AD continuum. Thus, we investigated whether the [18F]FDG‐PET signal in typical hypometabolic regions in AD is associated with the expression of ANLS transporters and enzymes in the healthy brain.MethodGene expression of GLUT1, GLUT3, MCT1, MCT2, MCT4, LDHA, and LDHB (ANLS genes) from postmortem brain tissue of healthy individuals were obtained from the Allen Human Brain Atlas. [18F]FDG‐PET data from cognitively unimpaired individuals were obtained from the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Pearson correlations were performed between the mean gene expression and the mean [18F]FDG‐PET SUVr across typically hypometabolic brain regions in AD (precuneus, angular and temporal gyri, and parietal and cingulate regions) and non‐vulnerable regions (uncorrected p‐value &lt; 0.05).ResultsThe expression of ANLS genes had a stronger positive correlation with [18F]FDG‐PET SUVr across the AD hypometabolic regions than the non‐vulnerable regions (p &lt; 0.05). Of note, the astrocytic glucose transporter GLUT1 presented a stronger correlation with [18F]FDG‐PET than the neuronal transporter GLUT3 in AD‐vulnerable regions. Figure 1 presents all correlations.ConclusionOur results show that the physiological expression of transporters and enzymes responsible for the brain glucose metabolism correlate more with the [18F]FDG‐PET signal in typical brain regions of the AD hypometabolic signature. This suggests these regions present a higher baseline activity and may be more susceptible to Aβ‐induced hyperactivation in early AD, which could lead to a bioenergetic collapse in later disease stages, as shown in the [18F]FDG‐PET of AD individuals.