Publications by authors named "Christopher J Heath"

Almost half of pregnant women globally are currently estimated to be overweight or obese. Rates of childhood obesity are also on the rise, in part because of increased consumption of dietary saturated fats. However, the long-term effect of peri- and postnatal high fat (HF) feeding on cognitive function and neuronal expression has not yet been investigated.

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The long non-coding RNA (lncRNA), HAR1A is emerging as a putative tumour suppressor. In non-neoplastic brain cells, REST suppresses HAR1A expression. In gliomas REST acts as an oncogene and is a potential therapeutic target.

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Article Synopsis
  • Sign-trackers show heightened responsiveness to cues linked with rewards, which may help understand psychiatric conditions.
  • Research indicates dopamine activity in the nucleus accumbens core (NAc) is tied to sign-tracking, but specific impacts on synaptic properties remain unclear.
  • A study found that experiencing a reward-paired cue without the reward decreased dendritic spine density in rats, especially in females, while increasing a presynaptic activity marker, emphasizing gender differences in behavior and neurobiology.
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In the mouse embryonic forebrain, developmentally distinct oligodendrocyte progenitor cell populations and their progeny, oligodendrocytes, emerge from three distinct regions in a spatiotemporal gradient from ventral to dorsal. However, the functional importance of this oligodendrocyte developmental heterogeneity is unknown. Using a genetic strategy to ablate dorsally derived oligodendrocyte lineage cells (OLCs), we show here that the areas in which dorsally derived OLCs normally reside in the adult central nervous system become populated and myelinated by OLCs of ventral origin.

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  • Metformin, commonly used to treat diabetes, was studied for its potential benefits in Alzheimer's disease (AD), but some research indicates it may actually increase AD risk and pathology in humans.
  • In a study involving prolonged metformin administration in mice, younger non-transgenic mice showed improvements in attention and learning, while older mice faced memory retention deficits and cognitive impairments, particularly in those with AD.
  • The treatment also led to increased levels of harmful AD-related proteins and decreased crucial synaptic markers, suggesting that the use of metformin for Alzheimer's patients warrants careful evaluation.
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  • Effort-based decision-making can be hard for people with mental health problems, which can affect their everyday lives.
  • Scientists were having trouble studying this in mice because the tests they used had issues that made it hard to get clear results.
  • A new test called Rearing-Effort Discounting (RED) was created for mice to make choices more simply, and it showed that this new method worked better, making it easier to understand how they make decisions.
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Alterations in neural pathways that regulate appetitive motivation may contribute to increased obesity risk in offspring born to mothers fed a high fat (HF) diet. However, current findings on the impact of maternal obesity on motivation in offspring are inconclusive, and there is no information about the long-lasting effects in aged animals. This study examined the longitudinal effect of perinatal and chronic postnatal HF intake on appetitive motivation in young and aged offspring.

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The COVID-19 pandemic led to the introduction of a range of infection prevention and control (IPC) measures that resulted in dramatic changes in people's lives however these IPC measures are not practiced consistently across the population. One predictor of an individual's responses to the pandemic is disgust sensitivity. Understanding how disgust sensitivity varies within the population could help to inform design of public health messages to promote more uniform behavioral change during future pandemics.

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α-Dystrobrevin (α-DB) is a major component of the dystrophin-associated protein complex (DAPC). Knockout (KO) of α-DB in the brain is associated with astrocytic abnormalities and loss of neuronal GABA receptor clustering. Mutations in DAPC proteins are associated with altered dopamine signaling and cognitive and psychiatric disorders, including schizophrenia.

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Long noncoding RNAs (lncRNAs) have a wide range of functions in health and disease, but many remain uncharacterized because of their complex expression patterns and structures. The genetic loci encoding lncRNAs can be subject to accelerated evolutionary changes within the human lineage.  is a region that has a significantly altered sequence compared to other primates and is a component of two overlapping lncRNA loci, and .

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Despite considerable advances in both in silico and in vitro approaches, in vivo studies that involve animal model systems remain necessary in many research disciplines. Neuroscience is one such area, with studies often requiring access to a complete nervous system capable of dynamically selecting between and then executing a full range of cognitive and behavioral outputs in response to a given stimulus or other manipulation. The involvement of animals in research studies is an issue of active public debate and concern and is therefore carefully regulated.

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Perseveration and apathy are two of the most common behavioural and psychological symptoms of dementia (BPSDs) in amyotrophic lateral sclerosis-frontotemporal dementia (ALS-FTD). Availability of a validated and behaviourally characterised animal model is crucial for translational research into BPSD in the FTD context. We behaviourally evaluated the male TDP-43 mouse, an ALS-FTD model with a human-equivalent mutation (TDP-43) knocked into the endogenous Tardbp gene.

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Compelling experimental and clinical evidence supports a role for maternal obesity in offspring health. Adult children of obese mothers are at greater risk of obesity, diabetes, coronary heart disease and stroke. These offspring may also be at greater risk of age-related neurodegenerative diseases for which mid-life obesity is a risk factor.

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Apathy is pervasive across many neuropsychiatric disorders but is poorly characterized mechanistically, so targeted therapeutic interventions remain elusive. A key impediment has been the lack of validated assessment tools to facilitate translation of promising findings between preclinical disease models and patients. Apathy is a common symptom in Huntington's disease.

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Genetic and pharmacological manipulations targeting metabotropic glutamate receptor 5 (mGluR5) affect performance in behavioural paradigms that depend on cognitive flexibility. Many of these studies involved exposing mice to highly stressful conditions including electric foot shocks or water immersion and forced swimming. Because mGluR5 is also implicated in resilience and stress responses, however, apparent impairments in inhibitory learning may have been an artifact of manipulation-induced changes in affective state.

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Disruptions to motivated behaviour are a highly prevalent and severe symptom in a number of neuropsychiatric and neurodegenerative disorders. Current treatment options for these disorders have little or no effect upon motivational impairments. We assessed the contribution of muscarinic acetylcholine receptors to motivated behaviour in mice, as a novel pharmacological target for motivational impairments.

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The 22q11.2 deletion syndrome (22q11.2DS) confers high risk of neurodevelopmental disorders such as schizophrenia and attention-deficit hyperactivity disorder.

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Rationale: Across species, effort-related motivation can be assessed by testing behaviour under a progressive ratio (PR) schedule of reinforcement. However, to date, PR tasks for rodents have been available using traditional operant response systems only.

Objectives: Touchscreen operant response systems allow the assessment of behaviour in laboratory rodents, using tasks that share high face validity with the computerised assessments used in humans.

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Rationale: Dysregulation of the serotonin (5-HT) system is a pathophysiological component in major depressive disorder (MDD), a condition closely associated with abnormal emotional responsivity to positive and negative feedback. However, the precise mechanism through which 5-HT tone biases feedback responsivity remains unclear. 5-HT2C receptors (5-HT2CRs) are closely linked with aspects of depressive symptomatology, including abnormalities in reinforcement processes and response to stress.

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Introduction: Tau is a microtubule-associated binding protein implicated in neurodegenerative tauopathies, including frontotemporal dementia (FTD) and Alzheimer's disease (AD). These diseases result in the intracellular accumulation of hyperphosphorylated tau in the form of neurofibrillary tangles, the presence of which is associated with cognitive deficits.

Methods: We conducted a longitudinal behavioral study to provide a profile of the TgTau(P301L)23027 transgenic mouse in multiple cognitive domains across multiple ages.

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Reliable and reproducible assessment of animal learning and behavior is a central aim of basic and translational neuroscience research. Recent developments in automated operant chamber technology have led to the possibility of universal standard protocols, in addition to increased translational potential, reliability and accuracy. However, the impact of regional and national differences in the supplies of available reinforcers in this system on behavioural performance and inter-laboratory variability is an unknown and at present uncontrolled variable.

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Satiety, rather than all or none, can instead be viewed as a cumulative decrease in the drive to eat that develops over the course of a meal. The nucleus accumbens (NAc) is known to play a critical role in this type of value reappraisal, but the underlying circuits that influence such processes are unclear. Although NAc cholinergic interneurons (CINs) comprise only a small proportion of NAc neurons, their local impact on reward-based processes provides a candidate cell population for investigating the neural underpinnings of satiety.

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Operant testing is a widely used and highly effective method of studying cognition in rodents. Performance on such tasks is sensitive to reinforcer strength. It is therefore advantageous to select effective reinforcers to minimize training times and maximize experimental throughput.

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Developmental nicotine exposure causes persistent changes in cortical neuron morphology and in behavior. We used microarray screening to identify master transcriptional or epigenetic regulators mediating these effects of nicotine and discovered increases in Ash2l mRNA, encoding a component of a histone methyltransferase complex. We therefore examined genome-wide changes in trimethylation of histone H3 on Lys4 (H3K4me3), a mark induced by the Ash2l complex associated with increased gene transcription.

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Rationale: A microdeletion at locus 15q13.3 is associated with high incidence rates of psychopathology, including schizophrenia. A mouse model of the 15q13.

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