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Full-Text Articles in Neuroscience and Neurobiology

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 …


Examining The Role Of Chloride Homeostasis And Pge2 Signaling In The Neuroendocrine Stress Response To Inflammation, Samuel A. Mestern Aug 2021

Examining The Role Of Chloride Homeostasis And Pge2 Signaling In The Neuroendocrine Stress Response To Inflammation, Samuel A. Mestern

Electronic Thesis and Dissertation Repository

The brain senses inflammatory signals and drives the release of glucocorticoids (GCs) — potent immunosuppressants — via the activation of the hypothalamic-pituitary-adrenal (HPA) axis. This inflammation-induced HPA axis activation is largely mediated by prostaglandin E2 (PGE2), acting on two subtypes of the PGE2 receptor, EP1 and EP3. Recently, our group revealed EP3 signaling mechanisms that excite HPA axis regulatory neurons. This thesis sought to tease out the remaining EP1 signaling mechanisms. Considering that the excitability of HPA axis regulatory neurons is constrained by GABAA receptor-mediated synaptic inhibition that relies on low-level intracellular Cl-. We hypothesized that PGE2-EP1 …


The Subplate And Its Role In The Gaba System In The Prefrontal Cortex, Gaeul Kyla Lee Dec 2020

The Subplate And Its Role In The Gaba System In The Prefrontal Cortex, Gaeul Kyla Lee

Electronic Thesis and Dissertation Repository

During early brain development, the subplate relays thalamocortical afferents. Lesions to the subplate have been implicated in developmental abnormalities of cortical GABAergic circuits. This thesis examined the effects of subplate lesions in the prefrontal cortex of rats on the expression of GABA markers (parvalbumin and GAD67) and GABA synapse maturation [potassium-chloride cotransporter (KCC2) and sodium-potassium- chloride cotransporter (NKCC1)] with relevance to the characterization of a rat model for schizophrenia. Lesions were made on postnatal day 1 (P1). Lesioned and control rats were sacrificed between P5 and P90 and immunolabelled for parvalbumin, GAD67, KCC2, and NKCC1. We found decreased parvalbumin expression …


Investigating The Role Of Cortical Inhibition In Tinnitus, Krystal Beh Jul 2017

Investigating The Role Of Cortical Inhibition In Tinnitus, Krystal Beh

Electronic Thesis and Dissertation Repository

Subjective tinnitus is characterized as the perception of a phantom sound with no external acoustic source, and is often described as a “ringing in the ears” sensation. While evidence supports a central origin for tinnitus, the underlying neural mechanisms for this condition remain elusive. The studies presented in this thesis offer significant contributions to understanding the neural basis of tinnitus by (1) validating a behavioural paradigm that can successfully screen rats for transient noise-induced tinnitus without any indications of false-positives, and (2) demonstrating that a local loss of inhibition is sufficient to induce gain enhancement in the primary auditory cortex, …


Cortical Cannabinoid Modulation Of Subcortical Dopamine Activity: Implications For Emotional Processing, Brittany Draycott Aug 2013

Cortical Cannabinoid Modulation Of Subcortical Dopamine Activity: Implications For Emotional Processing, Brittany Draycott

Electronic Thesis and Dissertation Repository

Humans receive countless sensory inputs from the outside world to which they assign a certain level of emotional significance. However, there are times when an individual may assign an abnormally high level of emotional salience to an otherwise non-significant event, resulting in an inappropriate allocation of attention as seen in the hallucinations and psychosis associated with schizophrenia. Several brain regions are involved in this emotional processing, including the medial prefrontal cortex (mPFC) and the ventral tegmental area (VTA). We have previously shown that activation of mPFC cannabinoid (CB1) receptors in rats causes a potentiated fear response to a normally non-salient …