scholarly journals A Biologically Inspired Computational Model of Basal Ganglia in Action Selection

2015 ◽  
Vol 2015 ◽  
pp. 1-24 ◽  
Author(s):  
Chiara Baston ◽  
Mauro Ursino
Keyword(s):  
Basal Ganglia ◽  
Previous History ◽  
Action Selection ◽  
Dopamine Depletion ◽  
Behavioral Experiments ◽  
Biologically Inspired ◽  
Cholinergic Interneurons ◽  
Hebb Rule ◽  
History Of

The basal ganglia (BG) are a subcortical structure implicated in action selection. The aim of this work is to present a new cognitive neuroscience model of the BG, which aspires to represent a parsimonious balance between simplicity and completeness. The model includes the 3 main pathways operating in the BG circuitry, that is, the direct (Go), indirect (NoGo), and hyperdirect pathways. The main original aspects, compared with previous models, are the use of a two-term Hebb rule to train synapses in the striatum, based exclusively on neuronal activity changes caused by dopamine peaks or dips, and the role of the cholinergic interneurons (affected by dopamine themselves) during learning. Some examples are displayed, concerning a few paradigmatic cases: action selection in basal conditions, action selection in the presence of a strong conflict (where the role of the hyperdirect pathway emerges), synapse changes induced by phasic dopamine, and learning new actions based on a previous history of rewards and punishments. Finally, some simulations show model working in conditions of altered dopamine levels, to illustrate pathological cases (dopamine depletion in parkinsonian subjects or dopamine hypermedication). Due to its parsimonious approach, the model may represent a straightforward tool to analyze BG functionality in behavioral experiments.

Difference in Ratio of Evertor to Invertor Activity Between the Dominant and Nondominant Legs During Simulated Lateral Ankle Sprain

2013 ◽  
Vol 22 (4) ◽  
pp. 272-278 ◽  
Author(s):  
Adam C. Knight ◽  
Wendi H. Weimar
Keyword(s):  
Outcome Measures ◽  
Ankle Sprain ◽  
Muscle Activity ◽  
Repeated Measures ◽  
Previous History ◽  
Physically Active ◽  
Lateral Ankle ◽  
History Of ◽  
University Laboratory

Context:The dominant and nondominant legs respond asymmetrically during landing tasks, and this difference may occur during an inversion perturbation and provide insight into the role of ankle-evertor and -invertor muscle activity.Objective:To determine if there is a difference in the ratio of evertor to invertor activity between the dominant and nondominant legs and outer-sole conditions when the ankle is forced into inversion.Design:Repeated-measures single-group design.Setting:University laboratory.Participants:15 physically active healthy volunteers with no previous history of an ankle sprain or lower extremity surgery or fracture.Interventions:An outer sole with fulcrum was used to cause 25° of inversion at the subtalar joint after landing from a 27-cm step-down task. Participants performed 10 fulcrum trials on both the dominant and nondominant leg.Main Outcome Measures:The ratio of evertor to invertor muscle activity 200 ms before and 200 ms after the inversion perturbation was measured using electromyography. This ratio was the dependent variable. Independent variables included outer-sole condition (fulcrum, flat), leg (dominant, nondominant), and time (prelanding, postlanding). The data were analyzed with separate 2-way repeated-measures ANOVA, 1 for the prelanding ratios and 1 for the postlanding ratios.Results:For the postlanding ratios, the fulcrum outer sole had a significantly greater (P < .05) ratio than the flat outer sole, and the nondominant leg had a significantly greater (P < .05) ratio than the dominant leg.Conclusions:These results indicate that a greater evertor response is produced when the ankle is forced into inversion, and a greater response is produced for the nondominant leg, which may function better during a postural-stabilizing task than the dominant leg.

scholarly journals Current concept of the pathogenesis of peri-implantitis and the role of bactéria.

2021 ◽  
Vol 3 (5) ◽  
pp. 09-30
Author(s):  
Anthony Davis ◽  
Mary Davis
Keyword(s):  
Previous History ◽  
Genetic Load ◽  
Current Concept ◽  
Risk Indicators ◽  
Cross Sectional ◽  
History Of ◽  
Periodontopathogenic Bacteria ◽  
Risk Situation ◽  
Edentulous Patients

Through an extensive review of the literature, our objective will be to clarify the current concept that exists about the pathogenesis of peri-implantitis, as well as the implications that bacteria may have on it. To date, different longitudinal and cross-sectional studies have identified some of the risk factors or risk indicators of peri-implantitis. Previous history of periodontal disease, diabetes, genetic load, poor oral hygiene, tobacco, alcohol consumption, absence of keratinized gingiva and the surface of the implants are some of the factors that have been analyzed in detail in the literature. The colonization of new surgically implanted surfaces represents a risk situation in partially edentulous patients, where periodontopathogenic bacteria from the residual bag play an important role.

scholarly journals Vaginal progesterone in prevention of preterm labour

2020 ◽  
Vol 8 (6) ◽  
pp. 449-454
Author(s):  
Dr. Prativa Sahoo ◽  
◽  
Dr. Nayan Kumar Patel ◽  
Dr. Ojaswini Patel ◽  
Dr. A.K Panigrahi ◽  
...  
Keyword(s):  
Preterm Birth ◽  
Pregnant Women ◽  
Preterm Labour ◽  
Previous History ◽  
Neonatal Morbidity ◽  
Primary Objective ◽  
Vaginal Progesterone ◽  
History Of ◽  
Secondary Objective

Introduction: Preterm birth, defined as childbirth occurring at less than 37 completed weeks or 259days of gestation since the first day of a woman’s last menstrual period, is one of the leading causesof neonatal morbidity and mortality. Across 184 countries, the rate of preterm birth ranges from 5%to 18% of babies born. Out of 27 million babies born every year (2018 data ) in India, 3.5 millionbabies born are premature. Recent literature review has shown that the use of Progesterone reducesrisk of preterm birth. But there is little information available regarding the role of Progesterone inpreventing preterm labour. Objectives: Primary objective of the study is to find out the incidence ofpreterm labour among pregnant women taking vaginal progesterone. Secondary objective istoassess the safety and efficacy of progesterone in feto-maternal outcome. Methods: This is a crosssectional study where100 prescriptions from IPD of Dept of O&G, VIMSAR, Burla of women who hadrecently undergone labour with singleton gestation and with previous history of preterm labour wereanalysed. Incidence of preterm labour among those taking and not taking vaginal progesterone werecompared. Results: There was decreased incidence of preterm labour as there is prolongation meanGestational age by 9.383 weeks among pregnant women taking vaginal progesterone. Conclusions:In the present study, women taking vaginal progesterone had significantly lowered incidencepreterm birth rate.

scholarly journals Aberrant striatal oscillations after dopamine loss in parkinsonian non-human primates

2019 ◽  
Author(s):  
Arun Singh ◽  
Stella M. Papa
Keyword(s):  
Basal Ganglia ◽  
Oscillatory Activity ◽  
Field Potentials ◽  
Striatal Neurons ◽  
Dopamine Depletion ◽  
Frequency Bands ◽  
Oscillatory Pattern ◽  
Motor Abnormalities ◽  
Beta Frequency

AbstractDopamine depletion in Parkinson’s disease (PD) is associated with abnormal oscillatory activity in the cortico-basal ganglia network. However, the oscillatory pattern of striatal neurons in PD remains poorly defined. Here, we analyzed the local field potentials in one untreated and five MPTP-treated non-human primates (NHP) to model advanced PD. Augmented oscillatory activity in the alpha (8-13 Hz) and low-beta (13-20 Hz) frequency bands was found in the striatum in parallel to the motor cortex and globus pallidus of the NHP-PD model. The coherence analysis showed increased connectivity in the cortico-striatal and striato-pallidal pathways at alpha and low-beta frequency bands, confirming the presence of abnormal 8-20 Hz activity in the cortico-basal ganglia network. The acute L-Dopa injection that induced a clear motor response normalized the amplified 8-20 Hz oscillations. These findings indicate that pathological striatal oscillations at alpha and low-beta bands are concordant with the basal ganglia network changes after dopamine depletion, and thereby support a key role of the striatum in the generation of parkinsonian motor abnormalities.

scholarly journals Role of low dose ecosprin and heparin in achieving live births in pregnancy with thrombophilia

2017 ◽  
Vol 6 (12) ◽  
pp. 5261
Author(s):  
Shilpa Asthana ◽  
Bandana Sodhi ◽  
Satish Kumar
Keyword(s):  
Low Dose ◽  
Previous History ◽  
Fetal Loss ◽  
Obstetric Outcomes ◽  
Obstetric Outcome ◽  
Live Births ◽  
History Of ◽  
Chi Square Analysis ◽  
In Pregnancy

Background: Thrombophilia is a disorder of haemostatic system that results in increased tendency of thrombus formation in both venous and arterial vascular system. The thrombotic events are not only restricted to venous thromboembolism but also can cause fetal loss (abortions or recurrent abortions and fetal demise), placental abruption, intrauterine growth restriction and severe pre-eclampsia. This study evaluates the role of administering thromboprophylaxis with heparin and ecosprin to patients with thrombophilia in pregnancy with previous history of adverse obstetric outcomes.Methods: This prospective study was conducted in 60 patients diagnosed with thrombophilia during pregnancy. The objective of the study was to determine the role of administering low dose ecosprin and heparin as thromboprophylaxis in achieving live births in these patients with thrombophilia. All patients included in this study were prophylactically administered low dose ecosprin with either unfractionated heparin (5000 IU s.c, BD) or low molecular weight heparin (40 mg s.c, OD) during pregnancy. Patients were followed up in the antenatal period and the obstetric outcome noted. Comparisons were made between the obstetric outcomes of these patients receiving the aforesaid thromboprophylaxis with those of previous untreated pregnancies during which no ecosprin or heparin had been administered. The data obtained were subjected to statistical analysis using Students ‘t’ test and Chi square analysis. P value <0.05 was considered statistically significant.Results: Fifty nine of the sixty patients with thrombophilia and previous adverse pregnancy outcome who received prophylaxis with ecosprin and heparin during the present pregnancy had live births (98.33%; p <0.0001). Fifty-eight (96.66%) of these patients progressed to term delivery and one (1.67%) pregnancy resulted in a pre-term birth.Conclusions: Present study reveals that prophylaxis with low dose ecosprin and heparin administered to patients with thrombophilia (acquired or inherited) with history of previous adverse obstetric outcome resulted in a positive outcome in terms of a significantly higher number of live births. However, larger studies are needed to further elaborate on the role of thromboprophylaxis in pregnancies with inherited thrombophilia.

Argentina's Missing Bones

2018 ◽  
Author(s):  
James P. Brennan
Keyword(s):  
Previous History ◽  
Revolutionary War ◽  
Social Protest ◽  
Crimes Against Humanity ◽  
Military Dictatorship ◽  
Dirty War ◽  
Role Of The State ◽  
State Terrorism ◽  
History Of

Missing Bones: the ‘Dirty War ’in Córdoba examines the history of state terrorism during Argentina’s 1976—83 military dictatorship in a single place: the industrial city of Córdoba, Argentina’s second largest city and the site of some of the dirty war’s greatest crimes. It examines the city’s previous history of social protest, working class militancy and leftist activism as an explanation for the particular nature of the dirty war there. Missing Bones examines both national and transnational influences on the counter-revolutionary war in Córdoba. The book also considers the legacy of this period and examines the role of the state in constructing a public memory of the violence and holding accountable those responsible through the most extensive trials for crimes against humanity to take place anywhere in Latin America.

scholarly journals Neuroleptic Malignant Syndrome Associated with Refractory Acute Disseminated Encephalomyelitis

2016 ◽  
Vol 8 (1) ◽  
pp. 92-96
Author(s):  
Silvia R. Delgado ◽  
Leticia Tornes ◽  
Janice Maldonado ◽  
Jeffrey Hernandez ◽  
Yesica Campos ◽  
...  
Keyword(s):  
Basal Ganglia ◽  
Neuroleptic Malignant Syndrome ◽  
Clinical Improvement ◽  
Acute Disseminated Encephalomyelitis ◽  
Dopamine Depletion ◽  
Intravenous Methylprednisolone ◽  
Intravenous Cyclophosphamide ◽  
Inflammatory Lesions ◽  
Significant Clinical Improvement

We present the case of a young man who was transferred to our hospital with worsening acute disseminated encephalomyelitis (ADEM) despite treatment with intravenous methylprednisolone, intravenous immunoglobulin and plasma exchange. He developed neuroleptic malignant syndrome (NMS) without the use of dopamine-modulating drugs. His progressive clinical improvement started after treatment with intravenous cyclophosphamide and methylprednisolone. In our patient, acute demyelination with severe bilateral inflammation of the basal ganglia could have caused a state of central dopamine depletion, creating proper conditions for the development of NMS. Significant clinical improvement of our case after treatment with intravenous cyclophosphamide and steroids provides further evidence for a possible role of the inflammatory lesions in the pathogenesis of NMS in association with ADEM.

555 Role of X-Ray Soft Tissue Neck in Children with Obstructive Sleep Apnea with a Previous History of Adenotonsillectomy

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A219-A220
Author(s):  
Quang Nguyen ◽  
Karim El-Kersh ◽  
Bakeerathan Gunaratnam ◽  
Egambaram Senthilvel
Keyword(s):  
Obstructive Sleep Apnea ◽  
Soft Tissue ◽  
Previous History ◽  
Z Score ◽  
X Ray ◽  
Soft Tissue Neck ◽  
Obstructive Sleep ◽  
History Of ◽  
The Mean

Abstract Introduction Adenoid recurrence in children after adenotonsillectomy can be an etiology for obstructive sleep apnea (OSA). The aim of this study was to assess the role of x-ray soft tissue neck (XR-STN) in evaluating adenoid recurrence from a sleep physician perspective and to assess the polysomnographic findings of pre and post revision adenoidectomy. Methods This was a single center retrospective study that included children &lt;18 years old with a history of adenotonsillectomy who underwent sleep study that confirmed the diagnosis of OSA and had XR- STN to evaluate for adenoidal tissue recurrence at the University of Louisville/Norton Pediatric Sleep Disorders clinic from July 2012 to September 2020. XR-STN level of adenoidal obliteration, baseline and post revision adenoidectomy PSG data were analyzed. Results A total of 160 subjects were included in the study with a mean age of 9.71±3.5 years, 59.4% were male, 54.4% were Caucasians, and the mean z-score was 1.77±1.15. XR-STN was normal in 39.4% of the subjects and it showed mild, moderate, and complete adenoidal obliteration in 20.6%, 32.5% and 7.5% of the subjects, respectively. Multiple regression analysis showed that the total AHI, the mean for the moderate and complete adenoidal obliteration are significantly higher than children with no obstruction (p-value=000). However, mild obliteration, Z score, age, gender, and race were not significantly associated with an increased total AHI. Pre- and post- adenoid revision PSGs were available in 20 subjects and they showed significant improvement in AHI (10.4±12.9 vs. 21.1±23.9, p=0.04), arousal index (15.4 ±10.6 vs. 21.1± 14.9, p=0.04), and nadir SaO2 (86.7%±8.1 vs. 76.58% ±18.44, p=0.04). Conclusion Soft tissue neck x-ray was useful in assessing adenoid recurrence in our study. Revision adenoidectomy resulted in an overall improvement in several PSGs parameters of OSA. Pediatric sleep physicians may consider XR-STN in the evaluation of children with OSA with a previous history of adenotonsillectomy. Support (if any) None

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