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1.
Artículo en Inglés | MEDLINE | ID: mdl-39349178

RESUMEN

BACKGROUND: People with schizophrenia (PSZ) show Impaired accuracy in spatial working memory (SWM), thought to reflect abnormalities in the sustained firing of feature selective neurons that are critical for successful encoding and maintenance processes. Recent research has documented a new source of variance in the accuracy of SWM: In healthy adults, SWM representations are unconsciously biased by prior trials such that current-trial responses are attracted to previous-trial responses (serial dependence). This opens a new window to examine how schizophrenia impacts both the sustained neural firing representing the current-trial target and longer-term synaptic plasticity that stores previous-trial information. METHODS: We examined response accuracy in a single-item SWM test with delay intervals of 0, 2, 4, or 8 seconds in 41 PSZ and 32 demographically similar healthy controls (HCS). Our main dependent variable was the bias index, which quantifies the extent to which the current-trial responses were biased toward or away from the previous-trial target. RESULTS: PSZ showed opposite-direction serial dependence bias effects: HCS showed an attractive bias which increased over increasing delays whereas PSZ showed a repulsion bias that increased over delays. In PSZ, the magnitude of the repulsion bias correlated negatively with broad measures of cognitive ability and WM capacity. CONCLUSIONS: PSZ show opposite-direction effects of previous trials on WM. Such qualitatively distinct differences in performance are extremely rare in psychopathology and may index a fundamental alteration in neural processing that could serve as a valuable biomarker for pathophysiology and treatment development research.

2.
J Orthop Res ; 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39177306

RESUMEN

The objective of the study was to evaluate tibial cartilage thickness (TCT), T1ρ and T2 values within both loaded and baseline configurations in a cadaveric knee model using a 3D bone based tibial coordinate system. Ten intact cadaveric knees were mounted into an magnetic resonance imaging (MRI) compatible loading device. Morphologic and quantitative MRI (qMRI) images were acquired with the knee in a baseline configuration and after application of 50% body weight. The morphologic images were evaluated for cartilage degeneration using a modified Noyes scoring system. A 3D bone-based tibial coordinate system was utilized to evaluate regional changes of tibial T1ρ, T2, and cartilage thickness values among regions covered and uncovered by the meniscus. Inter-regional differences in medial and lateral MRI outcomes were found between loaded and baseline configurations. Cartilage regions covered by the meniscus demonstrated disparate qMRI and TCT results as compared to cartilage regions not covered by the meniscus. The regions covered by meniscus experienced a ~3.5%, ~0.5%, and ~5.5% reduction of T1ρ (p < 0.05, medial and lateral compartments), T2 and TCT, respectively, in both compartments while regions not covered by the meniscus experienced larger reductions of ~10%, ~2%, and ~10.5% reduction of T1ρ (p < 0.05, medial and lateral compartments), T2 and TCT (p < 0.05, lateral compartment only), respectively, in both compartments. T1ρ and T2 decreases following application of 50% body weight load were substantially larger in the tibial regions with modified Noyes grade 3 (n = 2) compared to either healthy regions (n = 85, p < 0.0.003) or regions with modified Noyes grade 2 (n = 13, p < 0.004). Interregional differences in MRI outcomes reflect variations in structure and function, and largely followed a pattern in cartilage regions that were covered or not covered by the meniscus. Results of the current study suggest that ΔT1ρ and ΔT2 values may be sensitive to superficial fissuring, more than baseline or loaded T1ρ or T2 values, or TCT alone, however future studies with additional specimens, with greater variability in OA grade distribution, may further emphasize the current findings.

3.
J Clin Monit Comput ; 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39083121

RESUMEN

Dexmedetomidine decreases heart rate (HR) and increases high frequency (HF) component of HR variability (HRV). Analgesia Nociception Index (ANI) measures nociception by analyzing the influence of respiration on HF component of HRV while surgical pleth index (SPI) derives this information from photoplethymographic signals of finger arterioles. Therefore, during administration of dexmedetomidine, reliability of ANI may vary. This study compared the changes in ANI, SPI and hemodynamics (HR and mean arterial pressure [MAP]) during various noxious stimuli with fentanyl and dexmedetomidine intraoperative analgesia. In this trial, patients undergoing elective supratentorial surgery under general anesthesia were randomized to receive either fentanyl or dexmedetomidine infusion for intraoperative analgesia. ANI (instantaneous and mean), SPI, HR and MAP were compared before and after noxious stimuli (intubation, skull pin insertion, skin incision and craniotomy) with respect to magnitude of maximum change in the variable and the time taken for the maximal change (defined as response time) between the groups. A total of 58 patients, 29 in each group were recruited into the study. At intubation, SPI changed significantly more in the fentanyl group compared to dexmedetomidine group (37 versus 20 units, p = 0.007). At skull pinning, ANI values (both instantaneous and mean) changed more in dexmedetomidine group (p = 0.024 and 0.009) with significantly longer response time (p = 0.039). There was no difference between the groups with respect to any of the variables at skin incision and craniotomy. ANI during use of dexmedetomidine and SPI while using fentanyl, might be the better choices as intraoperative nociception monitors.

4.
Brain Inj ; : 1-8, 2024 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-39066898

RESUMEN

BACKGROUND: There is limited literature investigating the catecholamine levels in patients with paroxysmal sympathetic hyperactivity (PSH) after traumatic brain injury (TBI). The primary objective of this study was to correlate the severity of PSH (assessed using the PSH-Assessment measure [AM]) with plasma catecholamine levels at a resting state. METHODS: In this prospective case-control study, blood samples for epinephrine and norepinephrine estimation were obtained at rest on three consecutive days, only for 'cases' of PSH after severe TBI (s-TBI) and for control patients (matched for age, gender, and Glasgow coma scale [GCS]. RESULTS: Twenty-seven patients with PSH and 16 controls were recruited. The median PSH-AM score was 20 and 9 in cases and controls, respectively. The epinephrine and norepinephrine levels at rest did not correlate with the severity of PSH assessed during PSH paroxysms (p = 0.949 and 0.975). Norepinephrine levels increased in PSH patients over the 3 consecutive days, once PSH was diagnosed (p = 0.022). The length of hospital stay was longer and the motor-GCS score was lower in PSH patients, with no differences in other outcomes between the groups. CONCLUSION: Catecholamine levels in the inter-paroxysmal interval cannot be correlated with PSH severity assessed during the paroxysms. However, the results of the study need to be confirmed by a larger sample size as the study is underpowered.

6.
Front Neurosci ; 18: 1340528, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38379759

RESUMEN

Aberrant alterations in any of the two dimensions of consciousness, namely awareness and arousal, can lead to the emergence of disorders of consciousness (DOC). The development of DOC may arise from more severe or targeted lesions in the brain, resulting in widespread functional abnormalities. However, when it comes to classifying patients with disorders of consciousness, particularly utilizing resting-state electroencephalogram (EEG) signals through machine learning methods, several challenges surface. The non-stationarity and intricacy of EEG data present obstacles in understanding neuronal activities and achieving precise classification. To address these challenges, this study proposes variational mode decomposition (VMD) of EEG before feature extraction along with machine learning models. By decomposing preprocessed EEG signals into specified modes using VMD, features such as sample entropy, spectral entropy, kurtosis, and skewness are extracted across these modes. The study compares the performance of the features extracted from VMD-based approach with the frequency band-based approach and also the approach with features extracted from raw-EEG. The classification process involves binary classification between unresponsive wakefulness syndrome (UWS) and the minimally conscious state (MCS), as well as multi-class classification (coma vs. UWS vs. MCS). Kruskal-Wallis test was applied to determine the statistical significance of the features and features with a significance of p < 0.05 were chosen for a second round of classification experiments. Results indicate that the VMD-based features outperform the features of other two approaches, with the ensemble bagged tree (EBT) achieving the highest accuracy of 80.5% for multi-class classification (the best in the literature) and 86.7% for binary classification. This approach underscores the potential of integrating advanced signal processing techniques and machine learning in improving the classification of patients with disorders of consciousness, thereby enhancing patient care and facilitating informed treatment decision-making.

7.
J Am Acad Orthop Surg ; 32(1): e1-e12, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-37531453

RESUMEN

Martial arts are various systems of combat skills encompassing striking and grappling. Many styles have evolved into modern sports, and some have been included in the Olympics. The physicality of these can predispose practitioners to musculoskeletal injuries, such as anterior cruciate ligament ruptures; patellar, shoulder, or elbow instabilities; extremity fractures; and hand and spine injuries, which have been studied both clinically and biomechanically. The most common injury related to longer time loss from participation is an anterior cruciate ligament rupture. Higher injury incidence is associated with a higher level of experience and competition. Orthopaedic management of martial arts injuries should reflect the specific needs of each martial artist and the biomechanics of motions common to each style. Full-contact practitioners may benefit from broader surgical indications and special attention to the choice and positioning of implants; nonsurgical treatment may be appropriate for certain pediatric or noncontact practitioners. Approximately 60% of martial artists can return to the preinjury level of participation after a major injury. Injury prevention and rehabilitation programs should optimize neuromotor control and core engagement to ensure proper body mechanics. Gradual incorporation of martial arts movement into the postoperative physical therapy curriculum can benefit physical progress and help gain confidence toward full participation.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior , Traumatismos en Atletas , Artes Marciales , Ortopedia , Humanos , Niño , Fenómenos Biomecánicos , Artes Marciales/lesiones , Extremidad Superior/lesiones , Examen Físico , Traumatismos en Atletas/terapia , Traumatismos en Atletas/prevención & control
8.
J Anaesthesiol Clin Pharmacol ; 39(2): 208-214, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37564867

RESUMEN

Background and Aims: Patients with traumatic brain injury (TBI) frequently require emergency surgery. There is a paucity of literature with regard to anesthetic requirements in these patients. The aim of the study was to compare the dose of propofol required for induction of anesthesia in patients with different grades of TBI. Material and Methods: This prospective, observational study included patients with mild, moderate, and severe grades of TBI undergoing emergency surgery within 48 h of injury. Bispectral Index (BIS) values were recorded using a bilateral BIS sensor. Anesthesia was induced with a target controlled infusion (TCI) pump. Once BIS reached 40, plasma (Cp) and effect-site (Ce) concentration and total dose of propofol required were noted from the TCI pump. Results: Of the 96 patients recruited, 27, 36, and 33 patients belonged to mild, moderate, and severe TBI (sTBI) groups, respectively. The Ce of propofol in mild, moderate, and sTBI groups was 6 ± 0.9, 5.82 ± 0.98, and 4.48 ± 1.5 µg/mL (P < 0.001), and the dose of propofol required was 1.9 ± 0.2, 1.8 ± 0.4, 1.41 ± 0.5 mg/kg, respectively (P < 0.001). Baseline BIS on the injured side was 80 ± 7.8, 71 ± 9.4, 55 ± 11.6, and on the uninjured side was 89 ± 5.5, 81 ± 8.4, and 65 ± 12 in mild, moderate, and sTBI groups, respectively. Conclusions: The requirement of propofol was reduced in patients with sTBI. The dose of propofol required for induction of anesthesia as determined using Ce was significantly lower only between sTBI and mild TBI and not between patients with sTBI and moderate TBI or between mild and moderate head injury. BIS values were significantly different between the groups (highest in mild TBI and lowest in sTBI) and between normal and injured sides within each group.

9.
Asian J Psychiatr ; 88: 103734, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37619421

RESUMEN

OBJECTIVES: Modified ECT is routinely conducted using face mask (FM) and bag ventilation technique. Trans-nasal Humidified Rapid Insufflation Ventilatory Exchange (THRIVE) is a novel hands-free insufflation technique that provides oxygenation and prolongs apnoea time. There is limited literature comparing the two techniques. Primary objective of this study was to compare oxygen desaturation between THRIVE and FM techniques during ECT while secondary objective was to compare hemodynamics and complications. METHODS: Patients aged 18-50 years undergoing 3rd-5th ECT treatments were enrolled. First ECT was with FM technique followed by THRIVE (with LUBO collar) in the next ECT. Except for the oxygenation technique, the protocol for ECT administration was similar with both techniques. SpO2 values were recorded every minute for 10 min while hemodynamic parameters were measured at 2 min and 5 min following administration of electrical stimulus. Any drop in SpO2 below 92 % was considered as a desaturation event. RESULTS: A total of 201 patients underwent ECTs, one each with FM and THRIVE technique. Median age of patients was 28 years. There was no difference in SpO2 between the techniques (main effect P = 0.324, interaction P = 0.14). Only one patient had desaturation with THRIVE requiring intervention with FM. None of the patients had any airway complications in terms of nasal injury, hoarseness, or pneumothorax with THRIVE. CONCLUSION: THRIVE is a safe alternative option for hands-free oxygenation while administering ECT. However, considering patient safety, an anaesthesiologist competent in airway management must be readily available.

10.
Artículo en Inglés | MEDLINE | ID: mdl-37459911

RESUMEN

BACKGROUND: Impairments in working memory (WM) have been well documented in people with schizophrenia (PSZ). However, these quantitative WM impairments can often be explained by nonspecific factors, such as impaired goal maintenance. Here, we used a spatial orientation delayed response task to explore a qualitative difference in WM dynamics between PSZ and healthy control participants (HCs). More specifically, we took advantage of the discovery that WM representations may drift either toward or away from previous trial targets (serial dependence). We tested the hypothesis that WM representations would drift toward the previous trial target in HCs but away from the previous trial target in PSZ. METHODS: We assessed serial dependence in PSZ (n = 31) and HCs (n = 25) using orientation as the to-be-remembered feature and memory delays lasting from 0 to 8 seconds. Participants were asked to remember the orientation of a teardrop-shaped object and reproduce the orientation after a delay period of varying length. RESULTS: Consistent with prior studies, we found that current trial memory representations were less precise in PSZ than in HCs. We also found that WM for the current trial orientation drifted toward the previous trial orientation in HCs (representational attraction) but drifted away from the previous trial orientation in PSZ (representational repulsion). CONCLUSIONS: These results demonstrate a qualitative difference in WM dynamics between PSZ and HCs that cannot be easily explained by nuisance factors such as reduced effort. Most computational neuroscience models also fail to explain these results because they maintain information solely by means of sustained neural firing, which does not extend across trials. The results suggest a fundamental difference between PSZ and HCs in longer-term memory mechanisms that persist across trials, such as short-term potentiation and neuronal adaptation.


Asunto(s)
Memoria a Corto Plazo , Esquizofrenia , Humanos , Memoria a Corto Plazo/fisiología
11.
Schizophr Bull ; 49(6): 1591-1601, 2023 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-37350507

RESUMEN

BACKGROUND AND HYPOTHESES: Auditory verbal hallucinations (AVH) are central features of schizophrenia (SZ). However, AVH also occur in a small percentage of the general population who do not have a need for care, termed nonclinical voice hearers (NCVH). We sought to determine the degree to which the experience of AVH was similar in NCVH and in people with schizophrenia (PSZ) and evaluate the degree to which NCVH shared other features of SZ such as delusional beliefs, cognitive impairment, and negative symptoms. STUDY DESIGN: We recruited 76 people with a DSM-V diagnosis of SZ/schizoaffective disorder (PSZ; 49 with current AVH, 27 without), 48 NCVH, and 51 healthy controls. Participants received a broad battery of clinician-administered and self-report symptom assessments and a focused cognitive assessment. STUDY RESULTS: The AVH of NCVH and PSZ shared very similar sensory features. NCVH experienced less distress, had greater control over their AVH, and, unlike PSZ, rarely heard 2 voices speaking to each other. NCVH demonstrated a wide range of deeply held unusual beliefs, but reported less paranoia, and fewer first-rank symptoms such as passivity and alterations in self-experience. NCVH showed no evidence of cognitive deficits or negative symptoms. CONCLUSIONS: The AVH in NCVH and PSZ demonstrate important similarities as well as clear differences. Specific features, rather than the presence, of AVH appear to determine the need for care. NCVH do not share the cognitive and motivational deficits seen in PSZ. These results suggest that AVH and unusual beliefs can be separated from the broader phenotype of SZ.


Asunto(s)
Trastornos Psicóticos , Esquizofrenia , Voz , Humanos , Alucinaciones/etiología , Alucinaciones/diagnóstico , Trastornos Psicóticos/psicología , Esquizofrenia/complicaciones , Esquizofrenia/diagnóstico , Cognición
12.
Schizophr Res Cogn ; 33: 100288, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37273835

RESUMEN

Background: Sustained attention and vigilance impairments are well documented in people with schizophrenia (PSZ). The processes implicated in this impairment remain unclear. Here we investigated whether vigilance performance varied as a function of working memory load, and also examined the role of attentional lapsing that might arise from a loss of task set resulting in mind wandering. Method: We examined Continuous Performance Test Identical Pairs (CPT-IP) data from a cumulative sample of 247 (PSZ) and 238 healthy control (HC) participants collected over a series of studies. Results: PSZ performed more poorly that HC across conditions with signal/noise discrimination (d') decreasing with increasing working memory load across both groups However, there was a significant interaction of group and load suggesting that performance of PSZ was more negatively impacted by increasing load. We also found that PSZ has a significantly higher rate of attention lapsing than did HC. Discussion: Our results suggest that difficulties maintaining task set and working memory limitations are implicated in the impairments observed on the Identical Pairs CPT. Difficulties with task set maintenance appear to explain the majority of between-group variance, with a more subtle impact of increasing working memory load.

13.
J Neurosci Rural Pract ; 14(2): 286-292, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37181159

RESUMEN

Objectives: Moyamoya disease (MMD) leads to frequent ischemic/hemorrhagic manifestations. Our aim was to compare findings of arterial spin labeling (ASL) with dynamic susceptibility contrast (DSC) perfusion in patients of MMD. Materials and Methods: Patients diagnosed as MMD underwent magnetic resonance imaging with ASL and DSC perfusion sequences. Perfusion in bilateral anterior cerebral artery and middle cerebral artery territories at two levels (level of thalami and centrum semiovale) was graded as normal (score 1), or reduced (score 2) on DSC and ASL cerebral blood flow (CBF) maps by comparison with normal cerebellar perfusion. Time to peak (TTP) maps of DSC perfusion were also qualitatively scored as normal (score 1), or increased (score 2) similarly. Correlation between scores of ASL, CBF, DSC, CBF, and DSC, TTP maps was assessed by using Spearman's rank correlation. Results: Among the 34 patients, we did not find any significant correlation between the ASL CBF maps and DSC CBF maps (r = -0.028, P = 0.878), mean matching index 0.39 ± 0.31, whereas significant correlation was noted between the ASL CBF maps and DSC TTP maps (r = 0.58, P = 0.0003), mean matching index 0.79 ± 0.26. ASL CBF underestimated the perfusion compared to DSC perfusion. Conclusion: ASL perfusion CBF maps do not match the DSC perfusion CBF maps and rather match the TTP maps of DSC perfusion. This is explained by inherent problems in estimation of CBF in these techniques because of delay in arrival of label (in ASL perfusion) or contrast bolus (in DSC perfusion) due to the presence of stenotic lesions.

14.
bioRxiv ; 2023 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-37066149

RESUMEN

Background: Impairments in working memory(WM) have been well-documented in people with schizophrenia(PSZ). However, these quantitative WM impairments can often be explained by nonspecific factors, such as impaired goal maintenance. Here, we used a spatial orientation delayed-response task to explore a qualitative difference in WM dynamics between PSZ and healthy control subjects(HCS). Specifically, we took advantage of the discovery that WM representations may drift either toward or away from previous-trial targets(serial dependence). We tested the hypothesis that WM representations drift toward the previous-trial target in HCS but away from the previous-trial target in PSZ. Methods: We assessed serial dependence in PSZ(N=31) and HCS(N=25), using orientation as the to-be-remembered feature and memory delays from 0 to 8s. Participants were asked to remember the orientation of a teardrop-shaped object and reproduce the orientation after a varying delay period. Results: Consistent with prior studies, we found that current-trial memory representations were less precise in PSZ than in HCS. We also found that WM for the current-trial orientation drifted toward the previous-trial orientation in HCS(representational attraction) but drifted away from the previous-trial orientation in PSZ(representational repulsion). Conclusions: These results demonstrate a qualitative difference in WM dynamics between PSZ and HCS that cannot easily be explained by nuisance factors such as reduced effort. Most computational neuroscience models also fail to explain these results, because they maintain information solely by means of sustained neural firing, which does not extend across trials. The results suggest a fundamental difference between PSZ and HCS in longer-term memory mechanisms that persist across trials, such as short-term potentiation and neuronal adaptation.

15.
Clin Neurol Neurosurg ; 227: 107642, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36871389

RESUMEN

BACKGROUND: Delayed neurocognitive recovery (DNR) is commonly seen in patients in the postoperative period. Literature has shown that monitoring cerebral desaturation intraoperatively can predict the development of DNR in elderly patients undergoing surgery in prone position. This prospective observational study was conducted in patients of all ages, with the primary objective to determine the incidence of DNR and its correlation with cerebral oximetry. The secondary objectives were to determine if intraoperative cerebral desaturation influenced the neuropsychometric variables from preoperative to postoperative period. METHODS: This study included 61 patients, aged > 18 years undergoing spinal surgery in prone position. An evening before surgery and at 48 h postoperatively, patients were subjected to neuropsychological examination; Hindi Mental State Examination, Colour Trail Test 1 (CTT 1), CTT 2, Auditory Verbal Learning (AVLT) tests conducted by principal investigator (PI). DNR was defined as a 20% change in any of the test scores from the baseline. rSO2 was recorded bilaterally every 10 min throughout surgery by an independent person. Cerebral desaturation was defined as a 20% drop in rSO2 from the control value. RESULTS: The incidence of DNR was 24.6%. The duration of anesthesia and cerebral desaturation were found to be independently predictive of DNR, with each hour of anesthesia causing a two-fold increase in the chances of development DNR (P = 0.019) and presence of cerebral desaturation causing a 6-fold increase (P = 0.039). CTT 1 and CTT 2 tests had significantly larger increase in test scores in the postoperative period, in patients with cerebral desaturation. CONCLUSION: Duration of anesthesia and cerebral desaturation were factors predictive of the development of DNR in patients undergoing spine surgery in prone position.


Asunto(s)
Circulación Cerebrovascular , Oximetría , Anciano , Humanos , Incidencia , Estudios Prospectivos , Periodo Posoperatorio , Oxígeno
16.
JAMA Psychiatry ; 80(5): 515-517, 2023 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36884241

RESUMEN

Importance: Distinguishing delusions and hallucinations from unusual beliefs and experiences has proven challenging. Observations: The advent of neural network and generative modeling approaches to big data offers a challenge and an opportunity; healthy individuals with unusual beliefs and experiences who are not ill may raise false alarms and serve as adversarial examples to such networks. Conclusions and Relevance: Explicitly training predictive models with adversarial examples should provide clearer focus on the features most relevant to casehood, which will empower clinical research and ultimately diagnosis and treatment.


Asunto(s)
Alucinaciones , Redes Neurales de la Computación , Humanos , Alucinaciones/diagnóstico , Estado de Salud
17.
Cold Spring Harb Protoc ; 2023(1): 66-73, 2023 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-36167672

RESUMEN

Calcium-dependent nuclear import of LexA (CaLexA) and transcriptional reporter of intracellular calcium (TRIC) are transcription-based genetically encoded calcium indicators (transcriptional GECIs). When expressed in neurons, CaLexA and TRIC report neuronal activity by converting intracellular calcium levels into transcription activities and, subsequently, reporter gene expression. CaLexA and TRIC have been used successfully in many studies to label neurons associated with particular behaviors, regulated by internal states, or evoked by specific sensory inputs. This protocol details procedures for generating flies expressing genetic components of CaLexA and TRIC in specific neurons, performing immunostaining to label CaLexA and TRIC signals, and quantifying the signals using an open-source imaging analysis software.


Asunto(s)
Calcio , Dípteros , Animales , Calcio/metabolismo , Dípteros/metabolismo , Neuronas/metabolismo , Sistema Nervioso Central/metabolismo , Transporte Activo de Núcleo Celular
18.
Cold Spring Harb Protoc ; 2023(1): 8-18, 2023 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-36167674

RESUMEN

Knowing which neurons are active during behavior is a crucial step toward understanding how nervous systems work. Neuronal activation is generally accompanied by an increase in intracellular calcium levels. Therefore, intracellular calcium levels are widely used as a proxy for neuronal activity. Many types of synthetic components and bioluminescent or fluorescent proteins that report transient and long-term changes in intracellular calcium levels have been developed over the past 60 years. Calcium indicators that enable imaging of the dynamic activity of a large ensemble of neurons in behaving animals have revolutionized the field of neuroscience. Among these, transcription-based genetically encoded calcium indicators (transcriptional GECIs) have proven easy to use and do not depend on sophisticated imaging systems, offering unique advantages over other types of calcium indicators. Here, we describe the two currently available fly transcriptional GECIs-calcium-dependent nuclear import of LexA (CaLexA) and transcriptional reporter of intracellular calcium (TRIC)-and review studies that have used them. In the accompanying protocol, we present step-by-step details for generating CaLexA- and TRIC-ready flies and for imaging CaLexA and TRIC signals in dissected brains after experimental manipulations of intact free-moving flies.


Asunto(s)
Calcio , Drosophila , Animales , Drosophila/genética , Calcio/metabolismo , Neuronas/metabolismo , Indicadores y Reactivos , Señalización del Calcio/fisiología
19.
Indian J Anaesth ; 66(7): 505-510, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36111088

RESUMEN

Background and Aims: Analgesia Nociception Index (ANI) and Surgical Pleth Index (SPI) are measures of nociception-antinociception balance during general anaesthesia. The validity of these two monitors during autonomic changes brought about by intraoperative blood loss and noradrenaline infusion has not been studied earlier. The primary objective of the study was to determine the effect of bleeding on ANI and SPI. The secondary objective was to observe the effect of noradrenaline infusion on ANI and SPI and the correlation between ANI and SPI. Methods: In this prospective observational study, 43 patients undergoing surgery for excision of a meningioma or for traumatic brain injury were included. Heart rate, mean arterial pressure, ANI, SPI, response and state entropy were recorded every 5 min from anaesthetic induction till skin closure. ANI and SPI values before bleeding were compared with the values following bleeding. The effect of bleeding and noradrenaline on ANI and SPI were studied using linear mixed effect model. Results: Bleeding increased the values of ANI and the increase was higher in the presence of noradrenaline and it was statistically significant (P = 0.028 and 0.023). SPI was not affected by bleeding or with noradrenaline infusion. ANI and SPI had a poor negative correlation (r = - 0.01). Conclusion: Values of ANI increased significantly during episodes of intraoperative acute blood loss and with co-administration of noradrenaline. SPI seems to be more dependable when compared to ANI under such conditions.

20.
Proc Natl Acad Sci U S A ; 119(12): e2111283119, 2022 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-35286204

RESUMEN

SignificanceThe adult Drosophila mushroom body (MB) is one of the most extensively studied neural circuits. However, how its circuit organization is established during development is unclear. In this study, we provide an initial characterization of the assembly process of the extrinsic neurons (dopaminergic neurons and MB output neurons) that target the vertical MB lobes. We probe the cellular mechanisms guiding the neurite targeting of these extrinsic neurons and demonstrate that Semaphorin 1a is required in several MB output neurons for their dendritic innervations to three specific MB lobe zones. Our study reveals several intriguing molecular and cellular principles governing assembly of the MB circuit.


Asunto(s)
Cuerpos Pedunculados , Semaforinas , Animales , Neuronas Dopaminérgicas , Drosophila/fisiología , Cuerpos Pedunculados/fisiología , Neuritas , Semaforinas/genética
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