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The Journal of Neuroscience : the... Apr 2022Response inhibition is a core executive function enabling adaptive behavior in dynamic environments. Human and animal models indicate that inhibitory control and control...
Response inhibition is a core executive function enabling adaptive behavior in dynamic environments. Human and animal models indicate that inhibitory control and control networks are modulated by noradrenaline, arising from the locus coeruleus. The integrity (i.e., cellular density) of the locus coeruleus noradrenergic system can be estimated from magnetization transfer (MT)-sensitive magnetic resonance imaging (MRI), in view of neuromelanin present in noradrenergic neurons of older adults. Noradrenergic psychopharmacological studies indicate noradrenergic modulation of prefrontal and frontostriatal stopping-circuits in association with behavioral change. Here, we test the noradrenergic hypothesis of inhibitory control, in healthy adults. We predicted that locus coeruleus integrity is associated with age-adjusted variance in response inhibition, mediated by changes in connectivity between frontal inhibitory control regions. In a preregistered analysis, we used MT MRI images from = 63 healthy humans aged above 50 years (of either sex) who performed a Stop-Signal Task (SST), with atlas-based measurement of locus coeruleus contrast. We confirm that better response inhibition is correlated with locus coeruleus integrity and stronger connectivity between presupplementary motor area (preSMA) and right inferior frontal gyrus (rIFG), but not volumes of the prefrontal cortical regions. We confirmed a significant role of prefrontal connectivity in mediating the effect of individual differences in the locus coeruleus on behavior, where this effect was moderated by age, over and above adjustment for the mean effects of age. Our results support the hypothesis that in normal populations, as in clinical settings, the locus coeruleus noradrenergic system regulates inhibitory control. We show that the integrity of the locus coeruleus, the principal source of cortical noradrenaline, is related to the efficiency of response inhibition in healthy older adults. This effect is in part mediated by its effect on functional connectivity in a prefrontal cortical stopping-network. The behavioral effect, and its mediation by connectivity, are moderated by age. This supports the psychopharmacological and genetic evidence for the noradrenergic regulation of behavioral control, in a population-based normative cohort. Noradrenergic treatment strategies may be effective to improve behavioral control in impulsive clinical populations, but age, and locus coeruleus integrity, are likely to be important stratification factors.
Topics: Aged; Animals; Humans; Locus Coeruleus; Magnetic Resonance Imaging; Motor Cortex; Norepinephrine; Prefrontal Cortex
PubMed: 35277392
DOI: 10.1523/JNEUROSCI.1361-21.2022 -
Frontiers in Psychology 2020Both the control that people attribute to themselves over a situation (locus of control) and the control they attribute to themselves (self-control) have been proposed...
BACKGROUND
Both the control that people attribute to themselves over a situation (locus of control) and the control they attribute to themselves (self-control) have been proposed as aspects that can have an effect on internalizing problems in young people. There is little evidence of this relationship in the infantile-juvenile population in Latin America.
OBJECTIVE
To establish whether there is a significant predictive relationship of locus of control and self-control over internalizing and externalizing problems in the infantile-juvenile population, both at a general level and dimension-specific. These include depression, anxiety, social anxiety, somatic complaints, and post-traumatic stress.
METHODS
A cross-sectional-correlational study was carried out to establish if there was a possible predictive relationship in 3,664 schoolchildren of both primary (4th-6th grade) and secondary (7th-12th grade) in northern Chile, using the short version of the Nowicki-Strickland scale to measure locus of control, the Tangney scale to measure self-control, and the Child and Adolescent Evaluation System (SENA) to measure the dimensions of internalized problems.
HYPOTHESES
(1) Greater self-control is associated with lower levels of internalizing and externalizing problems. (2) Higher external locus of control is associated with higher levels of internalizing and externalizing problems. (3) Self-control, locus of control, and gender can together significantly predict each of the internalizing and externalizing problems.
RESULTS
Evidence is found to support the first two hypotheses fully and partially support the third, since gender did not function as a predictor in all models.
CONCLUSION
The results confirm previous international research in that both locus of control and self-control appear to have a significant influence on internalizing and externalizing problems. Implications for mental health promotion in this population are discussed.
PubMed: 32903499
DOI: 10.3389/fpsyg.2020.02015 -
The South African Journal of Psychiatry... 2019Research has consistently revealed a positive association between external locus of control and depression. Little, if any, research has investigated locus of control...
BACKGROUND
Research has consistently revealed a positive association between external locus of control and depression. Little, if any, research has investigated locus of control and depression in the sociocultural context of Botswana.
AIM
To explore the relationship between locus of control and depression among undergraduate students in Botswana and to determine the impact of age and gender on this relationship.
SETTING
University of Botswana.
METHODS
A sample of 272 students was surveyed through a self-administered questionnaire, which included the Levenson's multidimensional locus of control scale, the Beck Depression Inventory-II and demographic questions. Data analysis utilised descriptive statistics, correlation analysis, independent samples -tests and standard multiple regression analysis.
RESULTS
Of the 272 participants, 47.3% scored low (minimal) levels of depression, 23.4% scored mild levels, 18.0% scored moderate levels and 11.3% scored severe levels of depression. Students who believed that they were in control of events in their lives were less likely to present with depressive symptoms ( = -0.29, = 0.000), while students who believed that chance ( = 0.45, = 0.000) or powerful others ( = 0.40, = 0.000) controlled their lives were more likely to have high depression scores. Both internal and external locus of control, together with age, explained 31% of the variance in depression scores; gender made no significant contribution to levels of depression.
CONCLUSION
The study results draw attention to locus of control as one of the cognitive variables associated with depression. Further research is needed to determine how locus of control can be addressed in the treatment and prevention of depression in university contexts.
PubMed: 30899579
DOI: 10.4102/sajpsychiatry.v25i0.1221 -
European Journal of Pharmacology Apr 2008Although hypothalamic-pituitary-adrenal axis activation is generally considered to be the hallmark of the stress response, many of the same stimuli that initiate this... (Review)
Review
Although hypothalamic-pituitary-adrenal axis activation is generally considered to be the hallmark of the stress response, many of the same stimuli that initiate this response also activate the locus coeruleus-norepinephrine system. Given its functional attributes, the parallel engagement of the locus coeruleus-norepinephrine system with the hypothalamic-pituitary-adrenal axis serves to coordinate endocrine and cognitive limbs of the stress response. The elucidation of stress-related afferents to the locus coeruleus and the electrophysiological characterization of these inputs are revealing how the activity of this system is fine-tuned by stressors to facilitate adaptive cognitive responses. Emerging from these studies, is a picture of complex interactions between the stress-related neuropeptide, corticotropin-releasing factor (CRF), endogenous opioids and the excitatory amino acid neurotransmitter, glutamate. The net effect of these interactions is to adjust the activity and reactivity of the locus coeruleus-norepinephrine system such that state of arousal and processing of sensory stimuli are modified to facilitate adaptive behavioral responses to stressors. This review begins with an introduction to the basic anatomical and physiological characteristics of locus coeruleus neurons. The concept that locus coeruleus neurons operate through two activity modes, i.e., tonic vs. phasic, that determine distinct behavioral strategies is emphasized in light of its relevance to stress. Anatomical and physiological evidence are then presented suggesting that interactions between stress-related neurotransmitters that converge on locus coeruleus neurons regulate shifts between these modes of discharge in response to the challenge of a stressor. This review focuses specifically on the locus coeruleus because it is the major source of norepinephrine to the forebrain and has been implicated in behavioral and cognitive aspects of stress responses.
Topics: Adaptation, Physiological; Animals; Corticotropin-Releasing Hormone; Humans; Locus Coeruleus; Norepinephrine; Opioid Peptides; Stress, Physiological
PubMed: 18255055
DOI: 10.1016/j.ejphar.2007.11.062 -
Trends in Cognitive Sciences Mar 2016Research on cognitive aging has focused on how decline in various cortical and hippocampal regions influence cognition. However, brainstem regions play essential... (Review)
Review
Research on cognitive aging has focused on how decline in various cortical and hippocampal regions influence cognition. However, brainstem regions play essential modulatory roles, and new evidence suggests that, among these, the integrity of the locus coeruleus (LC)-norepinephrine (NE) system plays a key role in determining late-life cognitive abilities. The LC is especially vulnerable to toxins and infection and is often the first place Alzheimer's-related pathology appears, with most people showing at least some tau pathology by their mid-20s. On the other hand, NE released from the LC during arousing, mentally challenging, or novel situations helps to protect neurons from damage, which may help to explain how education and engaging careers prevent cognitive decline in later years.
Topics: Aging; Animals; Cognition; Humans; Locus Coeruleus; Neurons; Norepinephrine
PubMed: 26895736
DOI: 10.1016/j.tics.2016.01.001 -
Frontiers in Psychology 2021
PubMed: 34267714
DOI: 10.3389/fpsyg.2021.698917 -
Proceedings. Biological Sciences Jan 2011Intra-locus sexual conflict results when sex-specific selection pressures for a given trait act against the intra-sexual genetic correlation for that trait. It has been... (Review)
Review
Intra-locus sexual conflict results when sex-specific selection pressures for a given trait act against the intra-sexual genetic correlation for that trait. It has been found in a wide variety of taxa in both laboratory and natural populations, but the importance of intra-locus sexual conflict and sexually antagonistic genetic variation in hermaphroditic organisms has rarely been considered. This is not so surprising given the conceptual and theoretical association of intra-locus sexual conflict with sexual dimorphism, but there is no a priori reason why intra-locus sexual conflict cannot occur in hermaphroditic organisms as well. Here, I discuss the potential for intra-locus sexual conflict in hermaphroditic animals and review the available evidence for such conflict, and for the existence of sexually antagonistic genetic variation in hermaphrodites. I argue that mutations with asymmetric effects are particularly likely to be important in mediating sexual antagonism in hermaphroditic organisms. Moreover, sexually antagonistic genetic variation is likely to play an important role in inter-individual variation in sex allocation and in transitions to and from gonochorism (separate sexes) in simultaneous hermaphrodites. I also describe how sequential hermaphrodites may experience a unique form of intra-locus sexual conflict via antagonistic pleiotropy. Finally, I conclude with some suggestions for further research.
Topics: Animals; Biological Evolution; Genetic Variation; Hermaphroditic Organisms; Mating Preference, Animal; Models, Genetic
PubMed: 20719776
DOI: 10.1098/rspb.2010.1401 -
Frontiers in Psychology 2022Building upon the job demands-resources (JD-R) theory, this research offers an in-depth exploration of the mechanisms by which idiosyncratic deals (I-deals), such as...
Building upon the job demands-resources (JD-R) theory, this research offers an in-depth exploration of the mechanisms by which idiosyncratic deals (I-deals), such as personalized work arrangements, can enhance academics' psychological empowerment (PE) and hence affect their work engagement. This study's purpose was to investigate whether PE mediates the relationships between task and work responsibilities I-deals, flexibility I-deals, and work engagement among academics in higher education and whether the mediating effects are moderated by academics' internal locus of control. Using an online platform, the survey questionnaire was sent to 650 academics working in higher education. The results reveal that task and work responsibilities I-deals and flexibility I-deals, are positively associated with the academics' work engagement and that PE mediates those relationships. Additionally, the internal locus of control strengthens the positive relationship between task and work responsibilities I-deals and PE, and it enhances the indirect effect of task and work responsibilities I-deals on academics' work engagement through PE. Though, this study did not find the moderating effect of internal locus of control on the flexibility I-deals-PE relationship; however, the results indicate that internal locus of control boosts the indirect effect of flexibility I-deals on academics' work engagement through PE.
PubMed: 36467215
DOI: 10.3389/fpsyg.2022.923874 -
Proceedings of the National Academy of... Nov 2023Memory formation is typically divided into phases associated with encoding, storage, consolidation, and retrieval. The neural determinants of these phases are thought to...
Memory formation is typically divided into phases associated with encoding, storage, consolidation, and retrieval. The neural determinants of these phases are thought to differ. This study first investigated the impact of the experience of novelty in rats incurred at a different time, before or after, the precise moment of memory encoding. Memory retention was enhanced. Optogenetic activation of the locus coeruleus mimicked this enhancement induced by novelty, both when given before and after the moment of encoding. Optogenetic activation of the locus coeruleus also induced a slow-onset potentiation of field potentials in area CA1 of the hippocampus evoked by CA3 stimulation. Despite the locus coeruleus being considered a primarily noradrenergic area, both effects of such stimulation were blocked by the dopamine D1/D5 receptor antagonist SCH 23390. These findings substantiate and enrich the evidence implicating the locus coeruleus in cellular aspects of memory consolidation in hippocampus.
Topics: Rats; Animals; Locus Coeruleus; Optogenetics; Hippocampus; Neurons; Norepinephrine; Long-Term Potentiation
PubMed: 37931094
DOI: 10.1073/pnas.2307275120 -
Journal of Education and Health... 2020Hypertension is one of the major health threats in the world today. The purpose of this study was to find the relationship between hypertension with irrational health...
INTRODUCTION
Hypertension is one of the major health threats in the world today. The purpose of this study was to find the relationship between hypertension with irrational health belief and health locus of controls.
MATERIALS AND METHODS
The current work is a descriptive (case-control) study. One hundred patients with hypertension and 100 healthy individuals were included in the study through available sampling method. The Irrational Health Belief Scale and Multidimensional Health Locus of Control questionnaire were used. Data were analyzed using independent -test and logistic regression.
RESULTS
The findings showed a significant relationship between the variables of irrational health beliefs and the external health locus of control in hypertension. For a unit increase in an irrational health belief score, the chance of having high blood pressure increases by 6%, and for a unit increase in the score of external health locus of control, there is a 17% higher chance of having hypertension. The independent -test of irrational health belief also showed a statistically significant difference between the two groups ( < 0.01). There was also a statistically significant difference regarding the health locus of control in the two groups of hypertension and healthy individuals in the subscale of chance control ( < 0.01) and external locus of control ( < 0.01).
CONCLUSION
The results of this study make it necessary to identify irrational health beliefs as well as the health locus of control in individuals. Modification of these structures can be useful in the prevention and management of this chronic disease.
PubMed: 32642466
DOI: 10.4103/jehp.jehp_650_19