Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 839
Filter
1.
J Emerg Nurs ; 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38980247

ABSTRACT

OBJECTIVES: Back pain is a prevalent condition that affects 1 in 6 Australians at any time, with high associated health care costs. To date, there is limited information relating to symptom severity and recovery trajectory in people with back pain who present to the emergency department for care. A digital care pathway (DCP) can track patient outcomes following presentation with back pain. The primary aim of this protocol is to outline the co-development, implementation, and evaluation of a DCP for back pain patients who present to the emergency department. METHODS: The primary aim will be addressed in 3 overlapping phases: Phase 1 (co-design) will include interviews with back pain patients and health care professionals from the Northern Hospital Emergency Department. Interview findings will inform education resources featured on the DCP and establish questionnaire content and frequency acceptability. Phase 2 (implementation) will include the rollout of the DCP and tracking of patient-reported outcome measures, which will be collected over 12 weeks. Phase 3 (evaluation) will include interviews with a subset of back pain patients who have participated in Phase 2 to evaluate the acceptability of the DCP and the barriers and facilitators of using the DCP. ETHICS AND DISSEMINATION: This project has been approved via the National Health and Medical Research Council of Australia's National Mutual Acceptance Scheme by St Vincent's Hospital Human Ethics Committee (2022/PID06476), La Trobe University Research Governance (HEC#206/22), and Northern Health Research Governance (NH-2023-372687). We plan to publish the findings in a peer-reviewed journal and present them at conferences.

2.
Sci Signal ; 17(844): eadn6052, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38980922

ABSTRACT

Inhibitors of the transforming growth factor-ß (TGF-ß) pathway are potentially promising antifibrotic therapies, but nonselective simultaneous inhibition of all three TGF-ß homologs has safety liabilities. TGF-ß1 is noncovalently bound to a latency-associated peptide that is, in turn, covalently bound to different presenting molecules within large latent complexes. The latent TGF-ß-binding proteins (LTBPs) present TGF-ß1 in the extracellular matrix, and TGF-ß1 is presented on immune cells by two transmembrane proteins, glycoprotein A repetitions predominant (GARP) and leucine-rich repeat protein 33 (LRRC33). Here, we describe LTBP-49247, an antibody that selectively bound to and inhibited the activation of TGF-ß1 presented by LTBPs but did not bind to TGF-ß1 presented by GARP or LRRC33. Structural studies demonstrated that LTBP-49247 recognized an epitope on LTBP-presented TGF-ß1 that is not accessible on GARP- or LRRC33-presented TGF-ß1, explaining the antibody's selectivity for LTBP-complexed TGF-ß1. In two rodent models of kidney fibrosis of different etiologies, LTBP-49247 attenuated fibrotic progression, indicating the central role of LTBP-presented TGF-ß1 in renal fibrosis. In mice, LTBP-49247 did not have the toxic effects associated with less selective TGF-ß inhibitors. These results establish the feasibility of selectively targeting LTBP-bound TGF-ß1 as an approach for treating fibrosis.


Subject(s)
Extracellular Matrix , Fibrosis , Latent TGF-beta Binding Proteins , Transforming Growth Factor beta1 , Transforming Growth Factor beta1/metabolism , Animals , Humans , Latent TGF-beta Binding Proteins/metabolism , Latent TGF-beta Binding Proteins/antagonists & inhibitors , Extracellular Matrix/metabolism , Mice , Male , Kidney Diseases/metabolism , Kidney Diseases/pathology , Kidney Diseases/drug therapy , Disease Progression , Kidney/pathology , Kidney/metabolism , Kidney/drug effects , Mice, Inbred C57BL
3.
Ochsner J ; 24(2): 157-161, 2024.
Article in English | MEDLINE | ID: mdl-38912178

ABSTRACT

Background: Male breast cancer remains relatively underexplored in the medical literature. At present, male patients with breast cancer follow the same treatment guidelines as female patients with breast cancer, principally because of similar outcomes with treatment. However, this practice should not preclude generating evidence for male breast cancer surveillance, diagnosis, and management. BRCA2 gene mutations are associated with an increased risk of male breast cancer, along with lesser-known gene mutations that could also increase this risk, such as mutations of the BRIP1 gene. This case report presents a male patient with dual BRCA2 and BRIP1 deleterious gene mutations. To our knowledge, this combination has not been reported in the medical literature to date. Case Report: A 53-year-old male presented with a palpable symptomatic mass underneath the right nipple-areolar complex. Biopsies confirmed a poorly differentiated, infiltrating ductal carcinoma that was estrogen and progesterone receptor positive and human epidermal growth factor receptor-2 negative. The patient underwent a left modified radical mastectomy, with a right prophylactic simple mastectomy. Postoperatively, he underwent adjuvant chemotherapy and endocrine therapy. Conclusion: This novel case of genetically based male breast cancer with dual deleterious gene mutations provides insight into current treatment recommendations and the subtle differences between male breast cancer and female breast cancer. Engaging in discussions surrounding such rare cases not only raises awareness of male breast cancer but also indicates the need for further research aimed at establishing evidence-based management strategies for male patients with breast cancer.

4.
Arthroplast Today ; 27: 101386, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38812476

ABSTRACT

Background: The American Academy of Orthopaedic Surgeons (AAOS) Appropriate Use Criteria (AUC) for Surgical Management of Osteoarthritis of the Knee (2016) and Management of Osteoarthritis of the Hip (2017) are intended to provide treatment recommendations for osteoarthritis (OA). This study examined the agreement of AUC appropriateness classifications with arthroplasty surgeon recommendations for total knee arthroplasty (TKA) and total hip arthroplasty (THA). Methods: The cohort included 558 OA patients (397 knee, 161 hip) referred to a specialty arthroplasty clinic. Surgeons completed the online AAOS AUC patient profiles to generate appropriateness ratings. Surgeons' recommendations for treatment were recorded. We performed univariate and bivariate analyses to evaluate relationships between AUC appropriateness and surgeon recommendations. Results: The knee OA AUC classified TKA as "appropriate" for 309 (77.8%) of the 397 knee OA patients. Surgeons recommended TKA for 123 (31.0%), resulting in 46.8% (n = 186) higher rate of "appropriate" classification by AUC than TKA recommendation by surgeons. Weighted Cohen's κ demonstrated slight agreement (κ = 0.06, 95% confidence interval: 0.04, 0.09) between AUC appropriateness and surgeon TKA recommendation. The hip OA AUC classified THA as "appropriate" for 98 (60.9%) of the 161 hip OA patients. Surgeons recommended THA for 76 (47.2%), resulting in 13.7% (n = 22) higher rate of "appropriate" classification by AUC than THA recommendation by surgeons. Weighted Cohen's κ demonstrated moderate agreement (κ = 0.47, 95% confidence interval: 0.37, 0.57) between the AUC appropriateness classification and the surgeon's THA recommendation. Conclusions: AAOS AUC guidelines indicated surgical appropriateness significantly more than arthroplasty surgeons. AUC agreed slightly with surgeons for TKA and moderately for THA.

5.
J Am Acad Dermatol ; 2024 May 03.
Article in English | MEDLINE | ID: mdl-38705197

ABSTRACT

Longitudinal erythronychia (LE) is defined as a longitudinal red band of the nail(s) and is classified as localized (involvement of one nail) or polydactylous (involvement of more than one nail). The differential diagnosis is distinct for these classifications. The etiologies of localized longitudinal erythronychia (LLE) are most frequently benign subungual neoplasms, and less often malignancies. Polydactylous longitudinal erythronychia (PLE) is typically secondary to regional or systemic diseases, including lichen planus and Darier disease. LE is a common, but underrecognized clinical finding. Increased dermatologist awareness of the clinical characteristics and differential diagnosis for LE is necessary given the possibility for malignancy and associated systemic disease. In this clinical review, the clinical features, differential diagnosis, evaluation, and management of LE are described.

6.
Mol Psychiatry ; 2024 May 08.
Article in English | MEDLINE | ID: mdl-38719894

ABSTRACT

Post-traumatic stress disorder (PTSD) is a hypermnesic condition that develops in a subset of individuals following exposure to severe trauma. PTSD symptoms are debilitating, and include increased anxiety, abnormal threat generalization, and impaired extinction. In developing treatment strategies for PTSD, preclinical studies in rodents have largely focused on interventions that target post-encoding memory processes such as reconsolidation and extinction. Instead, here we focus on forgetting, another post-encoding process that regulates memory expression. Using a double trauma murine model for PTSD, we asked whether promoting neurogenesis-mediated forgetting can weaken trauma memories and associated PTSD-relevant behavioral phenotypes. In the double trauma paradigm, consecutive aversive experiences lead to a constellation of behavioral phenotypes associated with PTSD including increases in anxiety-like behavior, abnormal threat generalization, and deficient extinction. We found that post-training interventions that elevate hippocampal neurogenesis weakened the original trauma memory and decreased these PTSD-relevant phenotypes. These effects were observed using multiple methods to manipulate hippocampal neurogenesis, including interventions restricted to neural progenitor cells that selectively promoted integration of adult-generated granule cells into hippocampal circuits. The same interventions also weakened cocaine place preference memories, suggesting that promoting hippocampal neurogenesis may represent a broadly useful approach in hypermnesic conditions such as PTSD and substance abuse disorders.

8.
J Arthroplasty ; 2024 May 14.
Article in English | MEDLINE | ID: mdl-38750833

ABSTRACT

BACKGROUND: Achieving a minimal clinically important difference (MCID) in patient-reported outcomes following total knee arthroplasty (TKA) is common, yet up to 20% patient dissatisfaction persists. Unmet expectations may explain post-TKA dissatisfaction. No prior studies have quantified patient expectations using the same patient-reported outcome metric as used for MCID to allow direct comparison. METHODS: This was a prospective study of patients undergoing TKA with 5 fellowship-trained arthroplasty surgeons at one academic center. Baseline Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function (PF) and Pain Interference (PI) domains were assessed. Expected PROMIS scores were determined by asking patients to indicate the outcomes they were expecting at 12 months postoperatively. Predicted scores were generated from a predictive model validated in the Function and Outcomes Research for Comparative Effectiveness in Total Joint Replacement (FORCE-TJR) dataset. T-tests were used to compare baseline, expected, and predicted PROMIS scores. Expected scores were compared to PROMIS MCID values obtained from the literature. Regression models were used to identify patient characteristics associated with high expectations. RESULTS: There were 93 patients included. Mean age was 67 years (range, 30 to 85) and 55% were women. Mean baseline PROMIS PF and PI was 34.4 ± 6.7 and 62.2 ± 6.4, respectively. Patients expected significant improvement for PF of 1.9 times the MCID (MCID = 11.3; mean expected improvement = 21.6, 95% confidence interval [CI] 19.6 to 23.5, P < .001) and for PI of 2.3 times the MCID (MCID = 8.9; mean expected improvement = 20.6, 95% CI 19.1-22.2, P < .001). Predicted scores were significantly lower than expected scores (mean difference = 9.5, 95% CI 7.7 to 11.3, P < .001). No unique patient characteristics were associated with high expectations (P > .05). CONCLUSIONS: To our knowledge, this study is the first to quantify preoperative patient expectations using the same metric as MCID to allow for direct comparison. Patient expectations for improvement following TKA are ∼2× greater than MCID and are significantly greater than predicted outcome scores. This discrepancy challenges currently accepted standards of success after TKA and indicates a need for improved expectation setting prior to surgery.

10.
J Arrhythm ; 40(2): 342-348, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38586847

ABSTRACT

Background: Atrial fibrillation after cardiac surgery (POAF) is associated with increased morbidity and mortality. Several scores were used to predict POAF, with variable results. Thus, this study assessed the performance of several scoring systems to predict POAF after mitral valve surgery. Additionally, we identified the risk factors for POAF in those patients. Methods: This retrospective cohort included 1381 recruited from 2009 to 2021. The patients underwent mitral valve surgery, and POAF occurred in 233 (16.87%) patients. The performance of CHADS2, CHA2DS2-VASc, POAF, EuroSCORE II, and HATCH scores was evaluated. Results: The median age was higher in patients who developed POAF (60 vs. 54 years; p < .001). CHA2-DS2-VASc, POAF, EuroSCORE II, and HATCH scores significantly predicted POAF, with areas under the curve of the receiver operator curve (AUCROC) of 0.56, 0.61, 0.58, and 0.54, respectively. We identified age > 58 years, body mass index > 28 kg/m2, creatinine clearance < 90 mL/min, reoperative surgery, and preoperative inotropic and intra-aortic balloon pump use as predictors of POAF. We constructed a score from these variables (PSCC-AF). A score > 2 significantly predicted POAF (p < .001). The AUCROC of this score was 0.67, which was significantly higher than the AUCROC of the POAF score (p = .009). Conclusion: POAF after mitral valve surgery can be predicted based on preoperative patient characteristics. The new PSCC-AF score significantly predicted POAF after mitral valve surgery and can serve as a bedside diagnostic tool for POAF risk screening. Further studies are needed to validate the PSCC-AF-mitral score externally.

11.
Simul Healthc ; 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38595205

ABSTRACT

SUMMARY STATEMENT: Assessment tools support simulation facilitation skill development by guiding practice, structuring feedback, and promoting reflective learning among educators. This scoping review followed a systematic process to identify facilitation assessment tools used in postlicensure healthcare simulation. Secondary objectives included mapping of the validity evidence to support their use and a critical appraisal of their suitability for simulation faculty development in low-resource settings. Database searching, gray literature searching, and stakeholder engagement identified 11,568 sources for screening, of which 72 met criteria for full text review. Thirty sources met inclusion; 16 unique tools were identified. Tools exclusively originated from simulation practice in high-resource settings and predominantly focused on debriefing. Many tools have limited validity evidence supporting their use. In particular, the validity evidence supporting the extrapolation and implications of assessment is lacking. No current tool has high context suitability for use in low-resource settings.

12.
iScience ; 27(4): 109591, 2024 Apr 19.
Article in English | MEDLINE | ID: mdl-38632988

ABSTRACT

Targeting cancer metabolism to limit cellular energy and metabolite production is an attractive therapeutic approach. Here, we developed analogs of the bisbiguanide, alexidine, to target lung cancer cell metabolism and assess a structure-activity relationship (SAR). The SAR led to the identification of two analogs, AX-4 and AX-7, that limit cell growth via G1/G0 cell-cycle arrest and are tolerated in vivo with favorable pharmacokinetics. Mechanistic evaluation revealed that AX-4 and AX-7 induce potent mitochondrial defects; mitochondrial cristae were deformed and the mitochondrial membrane potential was depolarized. Additionally, cell metabolism was rewired, as indicated by reduced oxygen consumption and mitochondrial ATP production, with an increase in extracellular lactate. Importantly, AX-4 and AX-7 impacted overall cell behavior, as these compounds reduced collective cell invasion. Taken together, our study establishes a class of bisbiguanides as effective mitochondria and cell invasion disrupters, and proposes bisbiguanides as promising approaches to limiting cancer metastasis.

13.
J Cutan Pathol ; 51(7): 500-505, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38563529

ABSTRACT

This report describes the clinical, onychoscopic, nail clipping, and histopathologic features of a malignant onychopapilloma. A 71-year-old male presented to our outpatient clinic for a stable, asymptomatic lesion on his left middle finger that had been present for 2 years. Prior nail clipping histopathology showed nail plate thinning with subungual abnormal onychocytes. Clinical examination revealed a 2-mm-wide streak of longitudinal xanthonychia extending to the proximal nail fold, with distal hyperkeratosis and onycholysis. Onychoscopy showed irregular longitudinal nail plate ridging with scattered punctate hemorrhagic foci. An excisional nail unit biopsy demonstrated cellular atypia of the nail bed epithelium, matrix metaplasia, longitudinal abnormal onychocytes, increased Ki-67 staining, and negative HPV immunoperoxidase staining, confirming the diagnosis of malignant onychopapilloma.


Subject(s)
Nail Diseases , Skin Neoplasms , Humans , Male , Aged , Nail Diseases/pathology , Skin Neoplasms/pathology , Papilloma/pathology , Papilloma/surgery , Nails/pathology
15.
JAMA Dermatol ; 160(6): 691, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38598197
16.
Arthroplasty ; 6(1): 14, 2024 Mar 03.
Article in English | MEDLINE | ID: mdl-38431650

ABSTRACT

BACKGROUND: The coronal plane alignment of the knee (CPAK) classification was first developed using long leg radiographs (LLR) and has since been reported using image-based and imageless robotic total knee arthroplasty (TKA) systems. However, the correspondence between imageless robotics and LLR-derived CPAK parameters has yet to be investigated. This study therefore examined the differences in CPAK parameters determined with LLR and imageless robotic navigation using either generic or optimized cartilage wear assumptions. METHODS: Medial proximal tibial angle (MPTA) and lateral distal femoral angle (LDFA) were determined from the intraoperative registration data of 61 imageless robotic TKAs using either a generic 2 mm literature-based wear assumption (Navlit) or an optimized wear assumption (Navopt) found using an error minimization algorithm. MPTA and LDFA were also measured from preoperative LLR by two observers and intraclass correlation coefficients (ICCs) were calculated. MPTA, LDFA, joint line obliquity (JLO), and arithmetic hip-knee-ankle angle (aHKA) were compared between the robotic and the average LLR measurements over the two observers. RESULTS: ICCs between observers for LLR were over 0.95 for MPTA, LDFA, JLO, and aHKA, indicating excellent agreement. Mean CPAK differences were not significant between LLR and Navlit (all differences within 0.6°, P > 0.1) or Navopt (all within 0.1°, P > 0.83). Mean absolute errors (MAE) between LLR and Navlit were: LDFA = 1.4°, MPTA = 2.0°, JLO = 2.1°, and aHKA = 2.7°. Compared to LLR, the generic wear classified 88% and the optimized wear classified 94% of knees within one CPAK group. Bland-Altman comparisons reported good agreement for LLR vs. Navlit and Navopt, with > 95% and > 91.8% of measurements within the limits of agreement across all CPAK parameters, respectively. CONCLUSIONS: Imageless robotic navigation data can be used to calculate CPAK parameters for arthritic knees undergoing TKA with good agreement to LLR. Generic wear assumptions determined MPTA and LDFA with MAE within 2° and optimizing wear assumptions showed negligible improvement.

17.
Front Physiol ; 15: 1383996, 2024.
Article in English | MEDLINE | ID: mdl-38449782

ABSTRACT

[This corrects the article DOI: 10.3389/fphys.2023.1049994.].

18.
Article in English | MEDLINE | ID: mdl-38497759

ABSTRACT

BACKGROUND: Total joint arthroplasty aims to improve quality of life and functional outcomes for all patients, primarily by reducing their pain. This goal requires clinical practice guidelines (CPGs) that equitably represent and enroll patients from all racial/ethnic groups. To our knowledge, there has been no formal evaluation of the racial/ethnic composition of the patient population in the studies that informed the leading CPGs on the topic of pain management after arthroplasty surgery. QUESTIONS/PURPOSES: Using papers included in the 2021 Anesthesia and Analgesia in Total Joint Arthroplasty Clinical Practice Guidelines and comparing them with US National census data, we asked: (1) What is the representation of racial/ethnic groups in randomized controlled trials compared with their representation in the US national population? (2) Is there a relationship between the reporting of racial/ethnic groups and year of data collection/publication, location of study, funding source, or guideline section? METHODS: Participant demographic data (study year published, study type, guideline section, year of data collection, study site, study funding, study size, gender, age, and race/ethnicity) were collected from articles cited by this guideline. Studies were included if they were full text, were primary research articles conducted primarily within the United States, and if they reported racial and ethnic characteristics of the participants. The exclusion criteria included duplicate articles, articles that included the same participant population (only the latest dated article was included), and the following article types: systematic reviews, nonsystematic reviews, terminology reports, professional guidelines, expert opinions, population-based studies, surgical trials, retrospective cohort observational studies, prospective cohort observational studies, cost-effectiveness studies, and meta-analyses. Eighty-two percent (223 of 271) of articles met inclusion criteria. Our original literature search yielded 27 papers reporting the race/ethnicity of participants, including 24 US-based studies and three studies conducted in other countries; only US-based studies were utilized as the focus of this study. We defined race/ethnicity reporting as the listing of participants' race or ethnicity in the body, tables, figures, or supplemental data of a study. National census information from 2000 to 2019 was then used to generate a representation quotient (RQ), which compared the representation of racial/ethnic groups within study populations to their respective demographic representation in the national population. An RQ value greater than 1 indicates an overrepresented group and an RQ value less than 1 indicates an underrepresented group, relative to the US population. Primary outcome measures of RQ value versus time of publication for each racial/ethnic group were evaluated with linear regression analysis, and race reporting and manuscript parameters were analyzed with chi-square analyses. RESULTS: Two US-based studies reported race and ethnicity independently. Among the 24 US-based studies reporting race/ethnicity, the overall RQ was 0.70 for Black participants, 0.09 for Hispanic participants, 0.1 for American Indian/Alaska Natives, 0 for Native Hawaiian/Pacific Islanders, 0.08 for Asian participants, and 1.37 for White participants, meaning White participants were overrepresented by 37%, Black participants were underrepresented by 30%, Hispanic participants were underrepresented by 91%, Asian participants were underrepresented by 92%, American Indian/Alaska Natives were 90% underrepresented, and Native Hawaiian Pacific Islanders were virtually not represented compared with the US national population. On chi-square analysis, there were differences between race/ethnicity reporting among studies with academic, industry, and dual-supported funding sources (χ2 = 7.449; p = 0.02). Differences were also found between race/ethnicity reporting among US-based and non-US-based studies (χ2 = 36.506; p < 0.001), with 93% (25 of 27) of US-based studies reporting race as opposed to only 7% (2 of 27) of non-US-based studies. Finally, there was no relationship between race/ethnicity reporting and the year of data collection or guideline section referenced. CONCLUSION: The 2021 Anesthesia and Analgesia in Total Joint Arthroplasty Clinical Practice Guidelines provide evidence-based recommendations that reflect the current standards in orthopaedic surgery, but the studies upon which they are based overwhelmingly underenroll and underreport racial/ethnic minorities relative to their proportions in the US population. As these factors impact analgesic administration, their continued neglect may perpetuate inequities in outcomes after TJA. CLINICAL RELEVANCE: Our study demonstrates that all non-White racial/ethnic groups were underrepresented relative to their proportion of the US population in the 2021 Anesthesia and Analgesia in Total Joint Arthroplasty Clinical Practice Guidelines, underscoring a weakness in the orthopaedic surgery evidence base and questioning the overall external validity and generalizability of these combined CPGs. An effort should be made to equitably enroll and report outcomes for all racial/ethnic groups in any updated CPGs.

19.
Heliyon ; 10(6): e27782, 2024 Mar 30.
Article in English | MEDLINE | ID: mdl-38524620

ABSTRACT

An improved mutual coupling compensation in circularly polarized (CP) multi-input multi-output (MIMO) dielectric resonator antenna (DRA) is presented in this paper. Using trimming approach, the mutual coupling (MC) between closely spaced DRA units at 0.3λ has been significantly reduced while axial ratio performance has been maintained. Mutual coupling reduction is obtained by trimming the DRA to ensure low mutual coupling below -20dB. The exclusive features of the proposed MIMO DRA include wide impedance matching bandwidth (BW), triple band circular polarization, and suppressed MC between the radiating elements. The impedance bandwidth matches perfectly with a triple band's 3 dB axial ratio (AR). It is designed with characteristic mode analysis with good agreement of the measurement that has been obtained. Using the probe feed method, the DRA and patch strip are coupled together to allow bandwidth widening of the pro-posed DRA. An impedance bandwidth of 34% at a lower frequency to around 2% at a higher frequency was achieved in all resonance frequencies. Thus, we refer to our newly designed DRA as a proposed method for effectively reducing the mutual coupling between DRAs. Additionally, the 3 dB AR bandwidth matched at 3.3 GHz, 4.6 GHz, and 6.3 GHz with a percentage of 11.66%, 3.04%, and 2.22% obtained at the three different frequencies. Note that the proposed DRA exhibits low mutual coupling (below -20 dB) at the targeted frequencies, which is suitable for better signal reception for MIMO applications. By computing, the metrics envelop correlation coefficient, diversity gain, channel capacity loss, and total active reflection coefficient, the MIMO performance of the proposed antenna is verified. The experiments show a close result between simulated and computed validation of the proposed DRA.

20.
Neuron ; 112(9): 1487-1497.e6, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38447576

ABSTRACT

Little is understood about how engrams, sparse groups of neurons that store memories, are formed endogenously. Here, we combined calcium imaging, activity tagging, and optogenetics to examine the role of neuronal excitability and pre-existing functional connectivity on the allocation of mouse cornu ammonis area 1 (CA1) hippocampal neurons to an engram ensemble supporting a contextual threat memory. Engram neurons (high activity during recall or TRAP2-tagged during training) were more active than non-engram neurons 3 h (but not 24 h to 5 days) before training. Consistent with this, optogenetically inhibiting scFLARE2-tagged neurons active in homecage 3 h, but not 24 h, before conditioning disrupted memory retrieval, indicating that neurons with higher pre-training excitability were allocated to the engram. We also observed stable pre-configured functionally connected sub-ensembles of neurons whose activity cycled over days. Sub-ensembles that were more active before training were allocated to the engram, and their functional connectivity increased at training. Therefore, both neuronal excitability and pre-configured functional connectivity mediate allocation to an engram ensemble.


Subject(s)
Fear , Neurons , Optogenetics , Animals , Mice , Neurons/physiology , Neurons/metabolism , Fear/physiology , CA1 Region, Hippocampal/physiology , Hippocampus/physiology , Male , Mice, Inbred C57BL , Conditioning, Classical/physiology , Memory/physiology
SELECTION OF CITATIONS
SEARCH DETAIL
...