scholarly journals Orbitofrontal and Thalamic Influences on Striatal Involvement in Human Reversal Learning

2018 ◽  
Author(s):  
Tiffany Bell ◽  
Angela Langdon ◽  
Michael Lindner ◽  
William Lloyd ◽  
Anastasia Christakou
Keyword(s):  
Reversal Learning ◽  
Animal Studies ◽  
Dorsal Striatum ◽  
Response Strategy ◽  
Cholinergic Interneurons ◽  
Learning Tasks ◽  
Initial Learning ◽  
Before And After ◽  
Psychophysiological Interaction

ABSTRACTCognitive flexibility is crucial for adaptation and is disrupted in neuropsychiatric disorders and psychopathology. Human studies of flexibility using reversal learning tasks typically contrast error trials before and after reversal, which provides little information about the mechanisms that support learning and expressing a new response. However, animal studies suggest a specific role in this latter process for the connections between the dorsal striatum and the centromedian parafascicular (CM-Pf) thalamus, a system which may recruit the striatal cholinergic interneurons, but which is not well understood in humans. This study investigated the role of this system in human probabilistic reversal learning, specifically with respect to learning a new response strategy, contrasting its function to that of the better understood orbitoftontal-striatal systems. Using psychophysiological interaction (PPI) analysis of functional magnetic resonance imaging (fMRI) data we show that connectivity between the striatum and both the lateral orbitofrontal cortex (lOFC) and CM-Pf pathways increased during reversal, but not initial learning. However, while the strength of lOFC-striatal connectivity was associated with the speed of the reversal, the strength of CM-Pf-striatal connectivity was associated specifically with the quality of the reversal (reduced regressive errors). These findings expand our understanding of flexibility mechanisms in the human brain, bridging the gap with animal studies of this system.

scholarly journals Cortical and thalamic influences on striatal involvement in instructed, serial reversal learning; implications for the organisation of flexible behaviour.

2021 ◽  
Author(s):  
Brendan Williams ◽  
Anastasia Christakou
Keyword(s):  
Functional Connectivity ◽  
Cognitive Flexibility ◽  
Reversal Learning ◽  
Orbitofrontal Cortex ◽  
Dorsal Striatum ◽  
Response Strategy ◽  
Flexible Control ◽  
The Right ◽  
Serial Reversal

Cognitive flexibility is essential for enabling an individual to respond adaptively to changes in their environment. Evidence from human and animal research suggests that the control of cognitive flexibility is dependent on an array of neural architecture. Cortico-basal ganglia circuits have long been implicated in cognitive flexibility. In particular, the role of the striatum is pivotal, acting as an integrative hub for inputs from the prefrontal cortex and thalamus, and modulation by dopamine and acetylcholine. Striatal cholinergic modulation has been implicated in the flexible control of behaviour, driven by input from the centromedian-parafascicular nuclei of the thalamus. However, the role of this system in humans is not clearly defined as much of the current literature is based on animal work. Here, we aim to investigate the roles corticostriatal and thalamostriatal connectivity in serial reversal learning. Functional connectivity between the left centromedian-parafascicular nuclei and the associative dorsal striatum was significantly increased for negative feedback compared to positive feedback. Similar differences in functional connectivity were observed for the right lateral orbitofrontal cortex, but these were localised to when participants switched to using an alternate response strategy following reversal. These findings suggest that connectivity between the centromedian-parafascicular nuclei and the striatum may be used to generally identify potential changes in context based on negative outcomes, and the effect of this signal on striatal output may be influenced by connectivity between the lateral orbitofrontal cortex and the striatum.

scholarly journals Dissociable roles for the striatal cholinergic system in different flexibility contexts.

2021 ◽  
Author(s):  
Brendan Williams ◽  
Anastasia Christakou
Keyword(s):  
Reversal Learning ◽  
Cholinergic System ◽  
Dorsal Striatum ◽  
Resonance Spectroscopy ◽  
Prediction Errors ◽  
Behavioural Flexibility ◽  
Starting Point ◽  
Rate Of Learning ◽  
Striatal Cholinergic System

The production of behavioural flexibility requires the coordination and integration of information from across the brain, by the dorsal striatum. In particular, the striatal cholinergic system is thought to be important for the modulation of striatal activity. Research from animal literature has shown that chemical inactivation of the dorsal striatum leads to impairments in reversal learning. Furthermore, proton magnetic resonance spectroscopy work has shown that the striatal cholinergic system is also important for reversal learning in humans. Here, we aim to assess whether the state of the dorsal striatal cholinergic system at rest is related to flexible behaviour in reversal learning. We provide preliminary results showing that variability in choline in the dorsal striatum is significantly related to both the number perseverative and regressive errors that participants make, and their rate of learning from positive and negative prediction errors. These findings, in line with previous work, suggest the resting state of dorsal striatal cholinergic system has important implications for producing flexible behaviour. However, these results also suggest the system may have heterogeneous functionality across different types of tasks measuring behavioural flexibility. These findings provide a starting point for further interrogation into understanding the functional role of the striatal cholinergic system in flexibility.

scholarly journals The role of the cyclooxygenase products in evoking sympathetic activation in exercise

2007 ◽  
Vol 293 (3) ◽  
pp. H1861-H1868 ◽  
Author(s):  
Jian Cui ◽  
Patrick McQuillan ◽  
Afsana Momen ◽  
Cheryl Blaha ◽  
Raman Moradkhan ◽  
...  
Keyword(s):  
Animal Studies ◽  
Muscle Sympathetic Nerve Activity ◽  
Prostaglandin Synthesis ◽  
Pharmacological Agents ◽  
Exercise Pressor Reflex ◽  
Exercise Blood Pressure ◽  
Before And After ◽  
Pressor Reflex ◽  
Bier Block

Animal studies suggest that prostaglandins in skeletal muscles stimulate afferents and contribute to the exercise pressor reflex. However, human data regarding a role for prostaglandins in this reflex are varied, in part because of systemic effects of pharmacological agents used to block prostaglandin synthesis. We hypothesized that local blockade of prostaglandin synthesis in exercising muscles could attenuate muscle sympathetic nerve activity (MSNA) responses to fatiguing exercise. Blood pressure (Finapres), heart rate, and MSNA (microneurography) were assessed in 12 young healthy subjects during static handgrip and postexercise muscle ischemia (PEMI) before and after local infusion of 6 mg of ketorolac tromethamine in saline via Bier block (regional intravenous anesthesia). In the second experiment ( n = 10), the same amount of saline was infused via the Bier block. Ketorolac Bier block decreased the prostaglandins synthesis to ∼33% of the baseline. After ketorolac Bier block, the increases in MSNA from the baseline during the fatiguing handgrip was significantly lower than that before the Bier block (before ketorolac: Δ502 ± 111; post ketorolac: Δ348 ± 62%, P = 0.016). Moreover, the increase in total MSNA during PEMI after ketorolac was significantly lower than that before the Bier block ( P = 0.014). Saline Bier block had no similar effect. The observations indicate that blockade of prostaglandin synthesis attenuates MSNA responses seen during fatiguing handgrip and suggest that prostaglandins contribute to the exercise pressor reflex.

scholarly journals Dopaminergic Regulation of Striatal Interneurons in Reward and Addiction: Focus on Alcohol

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Rhona Clarke ◽  
Louise Adermark
Keyword(s):  
Physiological Activity ◽  
Dorsal Striatum ◽  
Primary Component ◽  
Medium Spiny Neurons ◽  
Dopaminergic Transmission ◽  
Cholinergic Interneurons ◽  
Guided Learning ◽  
Striatal Interneurons ◽  
Dopaminergic Regulation

Corticobasal ganglia networks coursing through the striatum are key structures for reward-guided behaviors. The ventral striatum (nucleus accumbens (nAc)) and its reciprocal connection with the ventral tegmental area (VTA) represent a primary component of the reward system, but reward-guided learning also involves the dorsal striatum and dopaminergic inputs from the substantia nigra. The majority of neurons in the striatum (>90%) are GABAergic medium spiny neurons (MSNs), but both the input to and the output from these neurons are dynamically controlled by striatal interneurons. Dopamine is a key neurotransmitter in reward and reward-guided learning, and the physiological activity of GABAergic and cholinergic interneurons is regulated by dopaminergic transmission in a complex manner. Here we review the role of striatal interneurons in modulating striatal output during drug reward, with special emphasis on alcohol.

Child and Adolescent Suicides in Bosnia and Herzegovina Before and After the War (1992–1995)

Crisis ◽  
2010 ◽  
Vol 31 (3) ◽  
pp. 160-164 ◽  
Author(s):  
Almir Fajkic ◽  
Orhan Lepara ◽  
Martin Voracek ◽  
Nestor D. Kapusta ◽  
Thomas Niederkrotenthaler ◽  
...  
Keyword(s):  
Bosnia And Herzegovina ◽  
Age Differences ◽  
Suicide Risk ◽  
Child And Adolescent ◽  
Youth Suicide ◽  
Southeastern Europe ◽  
Suicide Rates ◽  
Before And After ◽  
Sex And Age Differences

Background: Evidence on youth suicides from Southeastern Europe is scarce. We are not aware of previous reports from Bosnia and Herzegovina, which experienced war from 1992 to 1995. Durkheim’s theory of suicide predicts decreased suicide rates in wartime and increased rates afterward. Aims: To compare child and adolescent suicides in Bosnia and Herzegovina before and after the war. Methods: Data on youth suicide for prewar (1986–90) and postwar (2002–06) periods were analyzed with respect to prevalence, sex and age differences, and suicide methods. Suicide data from 1991 through 2001 were not available. Results: Overall youth suicide rates were one-third lower in the postwar than in the prewar period. This effect was most pronounced for girls, whose postwar suicide rates almost halved, and for 15–19-year-old boys, whose rates decreased by about a one-fourth. Suicides increased among boys aged 14 or younger. Firearm suicides almost doubled proportionally and were the predominant postwar method, while the most common prewar method had been hanging. Conclusions: The findings from this study indicate the need for public education in Bosnia and Herzegovina on the role of firearm accessibility in youth suicide and for instructions on safe storage in households. Moreover, raising societal awareness about suicide risk factors and suicide prevention is needed.

Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal
Keyword(s):  
Quality Of Life ◽  
Positive Impact ◽  
Wealth Distribution ◽  
Absolute Poverty ◽  
Before And After ◽  
The Status ◽  
Being There ◽  
The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

SUBLINGUAL VITAMIN D3 DRUG THERAPY IN VITAMIN D DEFICIENCY PATIENTS AT PRAVARA RURAL HOSPITAL

2019 ◽  
pp. 18-20
Author(s):  
Sanjeeva Kumar Goud T ◽  
Rahul Kunkulol
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Vitamin D3 ◽  
Serum Vitamin ◽  
Cross Sectional ◽  
Serum Vitamin D ◽  
Significant Difference ◽  
Before And After

The present study was aimed to study the effect of Sublingual Vitamin D3 on Serum Vitamin D level in Vitamin D deficiency patients. This was a cross-sectional and interventional study. All the Vitamin D deficiency patients of age 18-60years and either gender, willing to participate in the study were included. Patients who had greater than 20 ng/ml were excluded from the study. The total number of participants in our study was 200, out of these 111 males and 89 females, the mean age in our study was 51.07 ± 7.39Yrs. All volunteers were given sublingual vitamin D3 (60,000IU) in six doses every fifteen days of follow up for 3 months. The subject’s serum 25(OH)D levels were estimated before and after the treatment of sublingual vitamin D3. There was a statistically significant difference in serum vitamin D3 level before 16.61±6.71 ng/ml and after 35.80±7.80 ng/ml after treatment with Sublingual Vitamin D3. Six doses of 60,000IU of Vitamin D3 sublingual route having improved the role of serum 25(OH)D levels in the treatment of Vitamin D3 deficiency patients.Keywords: Vitamin D3; Sublingual route

Auditing the Systems Understanding Aid Project: An Integrative Assignment for Accounting Students

2012 ◽  
Vol 7 (1) ◽  
pp. 27-51 ◽  
Author(s):  
Susan L. Swanger ◽  
Beth H. Jones
Keyword(s):  
Active Learning ◽  
Teaching Methods ◽  
Work Environments ◽  
Accounting Students ◽  
External Work ◽  
Learning Tasks ◽  
Independent Auditors ◽  
Course Integration

ABSTRACT Accounting educators strive to prepare graduates for work in their chosen field. Various teaching methods can be employed to best accomplish this goal. One valuable tool is the use of active learning tasks that simulate external work environments. This paper describes the collaboration between an AIS and an Auditing professor who used an integrative task that spanned their two classes over two semesters. The authors had their AIS students complete Arens and Ward's Systems Understanding Aid (SUA) project (Arens & Ward, 2008). The following semester, students in the auditing class audited the records and financials that had been generated by students the previous semester. The project was designed to facilitate course integration and teamwork by having groups of students play the role of corporate accountants, then act as independent auditors.

Arthroscopy in Arthrosis: Is It Worth it? A case Presentation

2018 ◽  
Vol 69 (8) ◽  
pp. 2232-2235
Author(s):  
Marius Moga ◽  
Mark Edward Pogarasteanu ◽  
Antoine Edu
Keyword(s):  
Clinical Status ◽  
Loose Body ◽  
Point Of View ◽  
The Other ◽  
Joint Range Of Motion ◽  
Objective Evidence ◽  
Before And After ◽  
Total Knee ◽  
Joint Range

The role of arthroscopy in incipient and mild arthrosis, even combined with proximal tibial ostetomy, is well known and well documented. On the other hand, its role in the treatment of advanced arthrosis of the large joints, especially the knee, is a subject of controversy. The proponents of the use of arthroscopy in advanced arthrosis claim that meniscectomy, synovectomy, ostophytectomy, chondral lesion stabilization, arthroscopic release, plica and loose body removal greatly improve the quality of life for most patients, especially if followed by the use of viscoelastic injection, by diminishing pain and improving joint range of motion. The opponents claim that, even though the advantages are clear in the cases that refuse arthroplasty, in all the other cases the surgical indication should be total knee arthroplasty, as the clinical relief is temporary, but with all the risks of a surgical intervention. We have conducted an overview of the recent literature, in order to find objective evidence to sustain either point of view. We focused on articles published that included an objective measurement of before and after clinical status through clinical scores and objective measurements. We also focused on the follow-up period and on the evolution of the pathology after arthroscopy.

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