Publications by authors named "Wolmarans D"

Traumatic stress exposure increases noradrenaline (NA) release, which contributes to anxiety and impaired risk-appraisal. Guanfacine, a selective alpha-2A adrenergic receptor agonist, has been used to treat stress-related disorders characterised by impaired prefrontal cortex function. By acting on both presynaptic inhibitory autoreceptors and postsynaptic heteroreceptors, guanfacine attenuates stress reactivity and enhances cognition.

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Article Synopsis
  • The study examines the link between brain-immune mechanisms and neurocognitive rigidity in deer mice, particularly focusing on rigid motor stereotypy and systemic inflammation markers like the neutrophil-lymphocyte ratio (NLR).
  • Researchers administered a recombinant human granulocyte colony-stimulating factor (g-CSF) to increase NLR and observed its effects on stereotypical behavior, NLR, and plasma corticosterone levels.
  • Results indicated that NLR and plasma corticosterone levels did not predict stereotypical behavior, and while chronic g-CSF treatment raised NLR and lowered corticosterone, it did not affect stereotypical expressions; more research is needed to understand the potential immune-inflammation role in spontaneous stereotypy.
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Deer mice (Peromyscus maniculatus bairdii), a wildtype species native to North America, have been investigated for their spontaneous compulsive-like behaviour. The repetitive and persistence nature of three unique compulsive-like phenotypes in deer mice, i.e.

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Background: An increasing body of research implicates inflammatory processes, including alterations in the neutrophil-lymphocyte ratio (NLR), in the pathophysiology of psychiatric illness. The deer mouse (Peromyscus maniculatus bairdii) is commonly studied for its naturalistic expression of compulsive-like behaviour. Towards future efforts to gain an understanding of how innate and adaptive immune processes might be involved in this model, we aimed to study the effects of pegfilgrastim, a pegylated recombinant human granulocyte colony-stimulating factor (g-CSF) analogue, on the NLR of both male and female deer mice.

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Obsessive-compulsive disorder is a neuropsychiatric condition with notable genetic involvement. Against this background, laboratory-housed deer mice of both sexes varyingly present with excessive and persistent large nesting behavior (LNB), which has been validated for its resemblance of clinical compulsivity. Although LNB differs from normal nesting behavior (NNB) on both a biological and cognitive level, it is unknown to what extent the expression of LNB and NNB is related to familial background.

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Visual stimuli and limbic activation varyingly influence obsessive-compulsive symptom expression and so impact treatment outcomes. Some symptom phenotypes, for example, covert repugnant thoughts, are likely less sensitive to sensory stimuli compared to symptoms with an extrinsic focus, that is, symptoms related to contamination, safety, and "just-right-perceptions." Toward an improved understanding of the neurocognitive underpinnings of obsessive-compulsive psychobiology, work in naturalistic animal model systems is useful.

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Nesting is a normal, evolutionary conserved rodent behavioural phenotype that is expressed for purposes of breeding, safety, and thermal regulation. Further, nesting is commonly assessed as marker of overall rodent health and wellbeing, with poorer nesting performance generally proposed to resemble a worse state of health. Deer mice can be bidirectionally separated with 30 % of mice presenting with excessively large nesting behaviour (LNB).

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Cognitive rigidity (CR) refers to inadequate executive adaptation in the face of changing circumstances. Increased CR is associated with a number of psychiatric disorders, for example, obsessive-compulsive disorder, and improving cognitive functioning by targeting CR in these conditions, may be fruitful. Levetiracetam (LEV), clinically used to treat epilepsy, may have pro-cognitive effects by restoring balance to neuronal signalling.

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Trauma-related psychopathology transpires in some individuals after exposure to a life-threatening event. While aberrant adrenergic processes may contribute to this, a clear understanding of how said processes influence trauma-related conditions, remain inadequate. Here, we aimed to develop and describe a novel zebrafish (Danio rerio) model of life-threatening trauma-induced anxiety that may be representative of trauma related anxiety, and to evaluate the impact of stress-paired epinephrine (EPI) exposure in the model system.

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Obsessive-compulsive disorder (OCD) is characterized by recurring obsessive thoughts and repetitive behaviors that are often associated with anxiety and perturbations in cortico-striatal signaling. Given the suboptimal response of OCD to current serotonergic interventions, there is a need to better understand the psychobiological mechanisms that may underlie the disorder. In this regard, investigations into adenosinergic processes might be fruitful.

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Background: Some deer mice (Peromyscus maniculatus bairdii) exhibit various phenotypes of persistent behaviors. It remains unknown if and how said phenotypes associate with early-life and adult cognitive perturbations, and whether potentially cognitive enhancing drugs might modify such associations. Here, we explored the longitudinal relationship between early-life behavioral flexibility and the expression of persistent behavior in adulthood.

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Article Synopsis
  • The study aimed to find a new use for the drug trimetazidine in treating bipolar depression by analyzing how various drugs affect gene expression in neuronal-like cells.
  • Researchers screened a library of 960 approved drugs and identified trimetazidine, which boosts ATP production and showed increased mitochondrial respiration in lab tests.
  • In animal studies, trimetazidine demonstrated antidepressant-like effects, indicating its potential as a treatment for bipolar depression.
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Stereotypical expression in laboratory-housed rodents can be explained by different motivational, coping, and motor dysfunction theories. Here, we aimed to explore the neurocognitive underpinnings of high stereotypical (HS) expression in deer mice , previously proposed as a model system of compulsive-like behavioral persistence. Specifically, we aimed to establish whether HS behavior is related to an underlying escape-related trigger.

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Capture myopathy (CM), which is associated with the capture and translocation of wildlife, is a life-threatening condition that causes noteworthy morbidity and mortality in captured animals. Such wildlife deaths have a significant impact on nature conservation efforts and the socio-economic wellbeing of communities reliant on ecotourism. Several strategies are used to minimise the adverse consequences associated with wildlife capture, especially in ungulates, but no successful preventative or curative measures have yet been developed.

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Obsessive-compulsive disorder is varyingly associated with cognitive impairment, that is, deficits in spatial working memory, although it seems unlikely that this is generalised across all domains of functioning. Further, it is unclear whether symptoms will respond to potentially novel, non-serotonergic drugs that have shown promise as so-called cognitive enhancers. Here, we studied low (Norm-N; n = 31) and compulsive-like high (Comp-H; n = 34) stereotypical deer mice (Peromyscus maniculatus bairdii) to establish (1) whether there is a relationship between stereotypical intensity and working memory ability as measured by spontaneous T-maze arm alternation and (2) if and how stereotypy and its association with changes in working memory, would respond to the known anti-compulsive agent, escitalopram, and the proposed cognitive enhancer, levetiracetam.

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Background: Numerous studies have documented variation in transfusion practice for coronary artery bypass graft (CABG) surgery, despite the widespread availability of clinical guidelines. Blood management systems seek to streamline utilisation, with key indicators being patient care and outcome as well as reduction of waste and cost.

Objectives: To facilitate this view, this study sought to audit blood product utilisation for CABG surgery at a private and a public sector hospital in Western Cape Province, South Africa.

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The capacity to be self-aware is regarded as a fundamental difference between humans and other species. However, growing evidence challenges this notion, indicating that many animals show complex signs and behaviors that are consonant with self-awareness. In this review, we suggest that many animals are indeed self-aware, but that the complexity of this process differs among species.

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Large nest building behaviour (LNB), as expressed by a subpopulation of laboratory housed deer mice (Peromyscus maniculatus bairdii), is persistent and repetitive. However, the response of LNB to an anxiogenic environment has not yet been investigated. Here, we employed LNB and normal nesting (NNB) expressing mice, subdivided into three drug-exposed groups per cohort, i.

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Capture myopathy (CM) is a metabolic disease associated with mortality in mass boma captured (MBC) wildlife. The condition is induced by the forced pursuit, capturing, and restraint of wild animals, although its causal biology remains to be confirmed. A core feature of MBC-CM is rhabdomyolysis, which is associated with myoglobinuria and hyperthermia.

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Repetitive behavioral phenotypes are a trait of several neuropsychiatric disorders, including obsessive-compulsive disorder (OCD). Such behaviors are typified by complex interactions between cognitive and neurobiological processes which most likely contribute to the suboptimal treatment responses often observed. To this end, exploration of the adenosinergic system may be useful, since adenosine-receptor modulation has previously shown promise to restore control over voluntary behavior and improve cognition in patients presenting with motor repetition.

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This study aimed to further dissect the deer mouse (Peromyscus maniculatus bairdii) model of compulsive-like behavior with respect to two persistent-like behavioral phenotypes viz. large nest building (LNB) and high marble-burying (HMB), which may be relevant to understanding the neurobiology of different symptom dimensions in obsessive-compulsive and related disorders. Since LNB is sensitive to chronic, high dose escitalopram intervention but HMB is not, we assessed whether the two behaviors could be further distinguished based on their response to 4 weeks of uninterrupted serotoninergic intervention (i.

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Investigating the motivational triggers underlying naturalistic compulsive-like behavior is generally regarded as challenging. To this extent, the current study aimed to establish a proof-of-concept for future investigation by probing unconditioned and naturalistic operant responses aimed at obtaining nesting material by normal (NNB) and large (LNB) nest building deer mice (Peromyscus maniculatus bairdii). LNB mice and NNB controls were individually placed in cages equipped with a lever-operated nesting material (cotton rope) dispenser and allowed to become accustomed to the response (lever press)-outcome (obtaining cotton rope) contingency over seven nights.

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Cognitive flexibility, shown to be impaired in patients presenting with compulsions, is dependent on balanced dopaminergic and serotonergic interaction. Towards the development of a zebrafish (Danio rerio) screening test for anti-compulsive drug action, we manipulated social reward appraisal under different contexts by means of dopaminergic (apomorphine) and serotonergic (escitalopram) intervention. Seven groups of zebrafish (n = 6 per group) were exposed for 24 days (1 h per day) to either control (normal tank water), apomorphine (50 or 100 μg/L), escitalopram (500 or 1000 μg/L) or a combination (A100/E500 or A100/E1000 μg/L).

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Obsessive-compulsive disorder (OCD) is a psychiatric illness that significantly impacts affected patients and available treatments yield suboptimal therapeutic response. Recently, the role of the gut-brain axis (GBA) in psychiatric illness has emerged as a potential target for therapeutic exploration. However, studies concerning the role of the GBA in OCD are limited.

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Rodent marble-burying behavior in the marble-burying test (MBT) is employed as a model or measure to study anxiety- and compulsive-like behaviors or anxiolytic and anticompulsive drug action. However, the test responds variably to a range of pharmacological interventions, and little consensus exists regarding specific methodologies for its execution. Regardless, the test is widely applied to investigate the effects of pharmacological, genetic, and behavioral manipulations on purported behaviors related to the said neuropsychiatric constructs.

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