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Full-Text Articles in Neurosciences

Sex Differences In Mood And Anxiety-Related Outcomes In Response To Adolescent Nicotine Exposure, Tsun Hay Jason Ng Aug 2023

Sex Differences In Mood And Anxiety-Related Outcomes In Response To Adolescent Nicotine Exposure, Tsun Hay Jason Ng

Electronic Thesis and Dissertation Repository

Nicotine dependence is causally linked to increased risk of mood/anxiety disorders in later life. Females are reported to experience a higher prevalence of anxiety/depressive disorders and challenges in smoking cessation therapies, suggesting a potential sex-specific response to nicotine exposure and mood/anxiety disorder risk. However, pre-clinical evidence of sex-specific responses to adolescent nicotine exposure is unclear. Thus, to determine any sex differences in anxiety/depressive-related outcomes, adolescent male and female Sprague Dawley rats received nicotine (0.4 mg/kg; 3x daily) or saline injections for 10 consecutive days, followed by behavioural testing, in-vivo electrophysiology and Western Blot analyses. Our results revealed that adolescent nicotine …


Data-Driven Neuroanatomical Subtypes In Various Stages Of Schizophrenia: Linking Cortical Thickness, Glutamate, And Language Functioning, Liangbing Liang Dec 2022

Data-Driven Neuroanatomical Subtypes In Various Stages Of Schizophrenia: Linking Cortical Thickness, Glutamate, And Language Functioning, Liangbing Liang

Electronic Thesis and Dissertation Repository

The considerable variation in the spatial distribution of cortical thickness changes has been used to parse heterogeneity in schizophrenia. We aimed to recover a ‘cortical impoverishment’ subgroup with widespread cortical thinning. We applied hierarchical cluster analysis to cortical thickness data of three datasets in different stages of psychosis and studied the cognitive, functional, neurochemical, language and symptom profiles of the observed subgroups. Our consensus-based clustering procedure consistently produced a subgroup characterized by significantly lower cortical thickness. This ‘cortical impoverishment’ subgroup was associated with a higher symptom burden in a clinically stable sample and higher glutamate levels with language impairments in …


Investigating Gene-Environment Interaction In A Double-Hit Model For Autism Spectrum Disorder, Melvin Maroon Aug 2021

Investigating Gene-Environment Interaction In A Double-Hit Model For Autism Spectrum Disorder, Melvin Maroon

Undergraduate Student Research Internships Conference

With the exponential advancements seen in the field of sequencing technology, the science community has come to identify hundreds of potential genetic risk factors for neuropsychiatric disorders. Despite our knowledge that such risk factors exist, we have yet to understand their specific influences on the behavioral profile of an individual. In addition, maternal infection during pregnancy can have longstanding detrimental outcomes on a child’s development. This is especially impactful with the present threat of viral infection during the pandemic. Our study aims to understand the influence of a specific genetic and environmental factor on a preclinical rodent model’s behavioral development. …


Depression & Anxiety In Brain Vs. Body Trauma Patients, Olivia Mercier Aug 2021

Depression & Anxiety In Brain Vs. Body Trauma Patients, Olivia Mercier

Undergraduate Student Research Internships Conference

No abstract provided.


The Impact Of Levodopa Administration On Learning From Short-Term And Long-Term Action Consequences: A Paradigm Validation., Masood Rezaei Oct 2020

The Impact Of Levodopa Administration On Learning From Short-Term And Long-Term Action Consequences: A Paradigm Validation., Masood Rezaei

Electronic Thesis and Dissertation Repository

Behavioral and neuroimaging studies have identified two valuation systems in the human brain for controlling behavior known as model-free (MF) and model-based (MB). MF is based on immediate evaluation and MB is based on long-term evaluation of the outcome of our decisions. Previous studies suggest that dopamine baseline activity may play an important role in the balance between the two systems and determine how they compete or interact in controlling our actions. The overarching aims of this study is to investigate the impact of levodopa administration on learning from immediate and long-term action consequences, and to dissociate the role of …


Mouse Performance On A Novel Touchscreen Continuous Performance Task Is Dependent On Signaling In The Prelimbic Cortex, Tyler D. Dexter, Daniel Palmer, Amy C. Reichelt, Anita Taksokhan, Lisa M. Saksida, Tim J. Bussey Jun 2019

Mouse Performance On A Novel Touchscreen Continuous Performance Task Is Dependent On Signaling In The Prelimbic Cortex, Tyler D. Dexter, Daniel Palmer, Amy C. Reichelt, Anita Taksokhan, Lisa M. Saksida, Tim J. Bussey

Western Research Forum

Attention is the cognitive processing that facilitates the ability to target and attend to relevant environmental stimuli, while filtering out irrelevant or distracting stimuli. Control over selective attention is theorized to be dependent on organized neural communication that stems from the medial prefrontal cortex (mPFC). To evaluate selective and sustained attention, mice were trained on the novel touchscreen rodent continuous performance task (rCPT), a task designed to emulate the human CPT. In the rodent version, images are continuously presented on a touchscreen, where mice have been trained to selectively respond to one image type while suppressing responses to all others. …


White Matter Inflammation And Executive Dysfunction: Implications For Alzheimer Disease And Vascular Cognitive Impairment, Alexander Levit Nov 2018

White Matter Inflammation And Executive Dysfunction: Implications For Alzheimer Disease And Vascular Cognitive Impairment, Alexander Levit

Electronic Thesis and Dissertation Repository

White matter integrity is crucial to healthy executive function, the cognitive domain that enables functional independence. However, in the ageing brain, white matter is highly vulnerable. White matter inflammation increases with age and Alzheimer disease (AD), which disrupts the normal function of white matter. This may contribute to executive dysfunction, but the relationship between white matter inflammation and executive function has not been directly evaluated in ageing nor AD. White matter is also particularly vulnerable to cerebrovascular disease, corresponding with the common presentation of executive dysfunction in vascular cognitive impairment (VCI). Thus, white matter may be an important substrate by …


Neuronal Correlates For Neuroendocrine Habituation To Repeated Stress, Sara Matovic Dec 2017

Neuronal Correlates For Neuroendocrine Habituation To Repeated Stress, Sara Matovic

Electronic Thesis and Dissertation Repository

One way that the body actively responds to an impending stressor is by increasing systemic glucocorticoids through the activation of the hypothalamic-pituitary-adrenal (HPA) axis. While it is essential for short-term adaptation to stress, the sustained activation of the HPA axis during chronic stress can be detrimental and is linked to stress-related psychiatric conditions such as anxiety and depression. Therefore, it is important that the HPA axis adapts, or habituates, during chronic stress to minimize the negative consequences. Corticotropin releasing hormone (CRH) neurons in the paraventricular nucleus of the hypothalamus (PVN) function to assimilate incoming information from the stress circuitry and …


The Effects Of Pre- And Postnatal Administration Of Propionic Acid And Lipopolysaccharide On The Behaviour Of Adolescent Male And Female Rats, Kelly A. Foley Nov 2013

The Effects Of Pre- And Postnatal Administration Of Propionic Acid And Lipopolysaccharide On The Behaviour Of Adolescent Male And Female Rats, Kelly A. Foley

Electronic Thesis and Dissertation Repository

The gut microbiome plays an important role in immune functioning and neurodevelopment. Altered microbiome composition, leading to short chain fatty acid, and/or immune system dysfunction has been observed in children with autism spectrum disorders (ASD). This thesis describes the developmental influence of prenatal exposure to propionic acid (PPA), a metabolic fermentation product of enteric bacteria, or prenatal exposure to lipopolysaccharide (LPS), a bacterial mimetic and product of enteric bacteria, on a range of behaviours in male and female neonatal, adolescent and adult rats. Study one evaluated the effects of prenatal PPA and LPS, and postnatal PPA, on developmental milestones in …


Magnetic Resonance Imaging Of Brain Tissue Abnormalities: Transverse Relaxation Time In Autism And Tourette Syndrome And Development Of A Novel Whole-Brain Myelin Mapping Technique, Yann Gagnon Mar 2013

Magnetic Resonance Imaging Of Brain Tissue Abnormalities: Transverse Relaxation Time In Autism And Tourette Syndrome And Development Of A Novel Whole-Brain Myelin Mapping Technique, Yann Gagnon

Electronic Thesis and Dissertation Repository

The transverse relaxation time (T2) is a fundamental parameter of magnetic resonance imaging sensitive to tissue microstructure and water content, thus offering a non-invasive approach to evaluate abnormalities of brain tissue in-vivo. Prevailing hypotheses of two childhood psychiatric disorders were tested using quantitative T2 imaging and automated region of interest (ROI) analyses. In autism, the under-connectivity theory, which proposes aberrant connectivity within white matter (WM) was assessed, finding T2 to be eleveted in the frontal and parietal lobes, while dividing whole brain data into neurodevelopmentally relevant WM ROIs found increased T2 in bridging and radiate WM. In Tourette syndrome, tissue …


Sexual Reward And Depression, Andrea R. Di Sebastiano Oct 2012

Sexual Reward And Depression, Andrea R. Di Sebastiano

Electronic Thesis and Dissertation Repository

Sexual behavior in male rats is a complex rewarding behavior and many neurotransmitters and neuropeptides play an important role in mediation of sexual performance, motivation and reward. The hypothalamic neuropeptide orexin has been shown play a key role in reward associated with food and drugs of abuse, but the role of this neuropeptide in control of sexual performance, motivation and reward is currently unclear. First, it was shown that orexin neurons in the hypothalamus are activated during sexual performance and reward. Next, using cell specific lesions of orexin neurons it was demonstrated that orexin is involved in arousal and anxiety, …


Cognition As An Outcome Measure In Schizophrenia, Amresh Srivastava Jan 2007

Cognition As An Outcome Measure In Schizophrenia, Amresh Srivastava

Psychiatry Presentations

No abstract provided.


Atypical Antipsychotics And Cognitive Enhancement In Schizophrenia: The Current Status, Amresh Srivastava Jan 2007

Atypical Antipsychotics And Cognitive Enhancement In Schizophrenia: The Current Status, Amresh Srivastava

Psychiatry Presentations

No abstract provided.