Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 15 of 15

Full-Text Articles in Life Sciences

Age Impacts Perineuronal Net Density In The Somatosensory Genital Cortex Independently Of Gonadal Steroid Hormones, Ian D. Warren Dec 2023

Age Impacts Perineuronal Net Density In The Somatosensory Genital Cortex Independently Of Gonadal Steroid Hormones, Ian D. Warren

Masters Theses

A hallmark of pubertal development is the rise in gonadal hormone secretions and the subsequent onset of sexual behavior. The size of the somatosensory genital cortex increases in response to both this rise in gonadal steroid hormones and sexual experience. However, whether specific markers of brain plasticity are similarly impacted by gonadal hormones during puberty is not known. Perineuronal nets (PNNs) are specialized extracellular matrix structures that unsheathe neurons as they mature, and their maturation coincides with the closure of sensitive periods across several sensory systems. PNNs in somatosensory cortex, as an example, respond to experience-dependent plasticity. Although experience-depended changes …


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 …


Effects Of Development On Hpa Function Following Pubertal Stress, Brittany D. Elliott Jan 2023

Effects Of Development On Hpa Function Following Pubertal Stress, Brittany D. Elliott

Graduate Theses, Dissertations, and Problem Reports

For women, two of the greatest risk factors for affective disorders are adversity experienced during puberty and later becoming pregnant. We have created a translationally relevant mouse model where we address these complex risk factors. Previously, we discovered that pregnant mice (dams) that experienced chronic variable stress (CVS) during puberty display a blunted hypothalamic-pituitary-adrenal (HPA) response when exposed to an acute stressor. Interestingly, this alteration only first becomes apparent during pregnancy, which is a sensitive period for these effects due to normative neuroendocrine changes. Further investigation of the mechanisms underlying this dysfunction revealed altered gene expression in the paraventricular nucleus …


Impact Of Adolescent Social Isolation On Adult, Binge-Like Ethanol Consumption And Plasma Corticosterone In High-Alcohol-Preferring Mice, Eva Cullins Nov 2022

Impact Of Adolescent Social Isolation On Adult, Binge-Like Ethanol Consumption And Plasma Corticosterone In High-Alcohol-Preferring Mice, Eva Cullins

The Journal of Purdue Undergraduate Research

Adolescent stress exposure increases the likelihood of alcohol misuse and alcohol use disorder (AUD) in adulthood; however, it is not clear how genetic and environmental factors interact to increase risk. This study examined how adolescent social isolation affects adult binge-like ethanol drinking and levels of the stress hormone corticosterone in male and female mice with a genetic predisposition toward high alcohol preference (HAP). Twenty-eight HAP mice were separated into group-housed (GH) and socially isolated (SI) conditions (n = 13, 13). Binge drinking was assessed using a drinking in the dark (DID) procedure. Blood samples were taken before DID and after …


Sex Differences In Myelin Deficits And Neuroinflammatory Responses To Adolescent Drinking In Rats, Andrea Silva-Gotay Mar 2022

Sex Differences In Myelin Deficits And Neuroinflammatory Responses To Adolescent Drinking In Rats, Andrea Silva-Gotay

Doctoral Dissertations

Alcohol binge drinking during adolescence is associated with higher risk of developing alcohol use disorders later in life. Alcohol can lead to decreased white matter volume, myelin damage, and neuroinflammation in animal models of adolescent binge alcohol exposure. These deficits in turn are associated with cognitive disfunctions that are long-lasting and could contribute to alcohol abuse and alcoholism later in life. Importantly, human males are more likely to develop alcohol use disorders than females, thus the mechanisms underlying this might be different between the sexes. Understanding how alcohol impacts the developing adolescent brain can help us identify molecular and cellular …


Chronic Adolescent Stress As A Predictive Factor For The Risk Of Developing Ptsd-Like Symptoms In Adulthood, Grace K. Young Jan 2022

Chronic Adolescent Stress As A Predictive Factor For The Risk Of Developing Ptsd-Like Symptoms In Adulthood, Grace K. Young

Theses and Dissertations

Post-traumatic stress disorder is a stress and trauma based psychological disorder that is defined by the DSM-IV as an anxiety disorder that affects approximately 7.8% of people in the United States. PTSD is when those who suffer a traumatic event have intense and distressing feelings, emotions, and memories for a prolonged period of time after the event. A prominent feature of PTSD is the impaired ability to properly extinguish a fear response after a dangerous trigger or stressor is no longer present, also known as safety learning. Stressors are threats perceived within the environment that activate a response within the …


The Effects Of Adolescent Chronic Mild Stress: In Female Wistar-Kyoto Rats, Anna Hallowell Aug 2020

The Effects Of Adolescent Chronic Mild Stress: In Female Wistar-Kyoto Rats, Anna Hallowell

The Journal of Purdue Undergraduate Research

Despite years of research to understand under-lying mechanisms and develop more effective treatment approaches for mood disorders, numerous challenges exist. Many chronic stress models are used to study mood disorders, how-ever the majority have been established with adult males. This is problematic considering that affective disorders are more common in women, and generally develop during late adolescence. Studies have indicated fundamental behavioral, physiological, and neural differences between males and females in response to the same external stressors, furthering a need to develop sex-specific paradigms to accurately model the etiology of mood disorders in females. The Wistar-Kyoto (WKY) rat strain is …


Early Life Immune And Physical Stress Directly Influences Anxiety-Like Behaviour In Adolescent Rats: Examining Sex Differences, Jordan M. Ward Aug 2017

Early Life Immune And Physical Stress Directly Influences Anxiety-Like Behaviour In Adolescent Rats: Examining Sex Differences, Jordan M. Ward

Electronic Thesis and Dissertation Repository

This thesis examined the effects of neonatal acute immune activation with the endotoxin, lipopolysaccharide (LPS) on postnatal days 3 and 5 on adolescent anxiety-like behaviour in rats before and after a stress period. Previous research has shown that adults rats exposed to LPS during the neonatal stage show anxiety-like behaviour following a period of stress. This thesis investigated this effect in adolescence. The present results showed significantly higher anxiety-like behaviour in saline controls, and a potential neuroprotective effect of low dose LPS (15 µg/kg) contrary to what was reported in adult rats. As well, a phase of stressful, aversive conditioning …


Effects Of Adolescent Alcohol Binge Drinking On Prefrontal Myelin, Wanette M. Vargas-Rodriguez Nov 2016

Effects Of Adolescent Alcohol Binge Drinking On Prefrontal Myelin, Wanette M. Vargas-Rodriguez

Doctoral Dissertations

Alcohol binge drinking is highly prevalent in teenagers and is associated with various harmful health effects and social problems. During adolescence, brain regions such as the prefrontal cortex (PFC) are still undergoing active development, characterized by increases in white matter volume. While the morphological details and the cellular and molecular sequences governing adolescent white matter development are not fully known, it is known that this development process is sensitive and can be disrupted. Although consumption of alcohol in a binge drinking pattern has been linked to lower white matter integrity in humans, it is important to determine if alcohol is …


Characterization Of Corticotropin-Releasing Factor Cells In The Medial Prefrontal Cortex Of Rats, Yi-Ling Lu Mar 2016

Characterization Of Corticotropin-Releasing Factor Cells In The Medial Prefrontal Cortex Of Rats, Yi-Ling Lu

Doctoral Dissertations

Corticotropin-releasing factor (CRF) is the major peptide involved in regulating the body’s autonomic, hormonal, and behavioral responses to stress. Cells that produce and release this peptide are widely distributed throughout the brain. This dissertation focuses on a specific population of CRF cells residing in the medial prefrontal cortex (mPFC) that could potentially influence a number of higher order functions through modulation of local circuits. The prefrontal cortex is known to function sub-optimally in patients suffering from various stress-related psychiatric conditions including alcohol use disorder (AUD), and dysregulated CRF signaling may be an underlying mechanism. Surprisingly little is known about this …


An Analysis Of The Interaction Of Methylphenidate And Nicotine In Adolescent Rats: Effects On Bdnf, Elizabeth D. Freeman Aug 2015

An Analysis Of The Interaction Of Methylphenidate And Nicotine In Adolescent Rats: Effects On Bdnf, Elizabeth D. Freeman

Electronic Theses and Dissertations

This investigation was an analysis of the interaction of adolescent exposure to methylphenidate (MPH; trade name: Ritalin) on nicotine sensitization and conditioned place preference (CPP) in a rodent model and underlying mechanisms of this effect. Animals were treated IP with 1 mg/kg MPH or saline using a ―school day‖ regimen of five days on, two days off, from postnatal day (P) 28-50. During the final two weeks of MPH treatment, animals were either behaviorally sensitized to nicotine (0.5 mg/kg free base) or saline for 10 days, or conditioned to nicotine or saline using the CPP behavioral paradigm. In addition, three …


The Short And Long-Term Effects Of Chronic Ketamine During Adolescence On Object Recognition Memory In Rats, William Hardin May 2015

The Short And Long-Term Effects Of Chronic Ketamine During Adolescence On Object Recognition Memory In Rats, William Hardin

Seton Hall University Dissertations and Theses (ETDs)

Prior research has demonstrated that ketamine causes deficits in object recognition and location memory following both acute and chronic administration (Pitsikas & Boultadakis, 2009; Venãncio et al., 2011). Although it is well established that abuse of many different kinds of drugs during the critical developmental period of adolescence can lead to impairments in cognition later in adulthood (Gilpin et al., 2012; Wagner et al., 2010), no research has investigated the effects of chronic ketamine administration during adolescence and its effects on behavior in adulthood. With recent research establishing that chronic ketamine during adolescence produces late-onset alterations in electrophysiology during adulthood …


In Search Of The Neurobiological Substrates For Social Playfulness In Mammalian Brains, Stephen M. Siviy, Jaak Panksepp Oct 2011

In Search Of The Neurobiological Substrates For Social Playfulness In Mammalian Brains, Stephen M. Siviy, Jaak Panksepp

Psychology Faculty Publications

Play behavior is a fundamental and intrinsic neurobehavioral process in the mammalian brain. Using rough-and-tumble play in the juvenile rat as a model system to study mammalian playfulness, some of the relevant neurobiological substrates for this behavior have been identified, and in this review this progress. A primary-process executive circuit for play in the rat that includes thalamic intralaminar nuclei, frontal cortex and striatum can be gleaned from these data. Other neural areas that may interact with this putative circuit include amygdala, ventral hypothalamus, periaqueductal gray (PAG), and deep tectum, as well as ascending dopamine systems which participate in all …


Effects Of Chlordiazepoxide On Predator Odor-Induced Reductions Of Playfulness In Juvenile Rats, Stephen M. Siviy, Courtney L. Steets, Lauren M. Debrouse Jan 2010

Effects Of Chlordiazepoxide On Predator Odor-Induced Reductions Of Playfulness In Juvenile Rats, Stephen M. Siviy, Courtney L. Steets, Lauren M. Debrouse

Psychology Faculty Publications

The extent to which a non-sedative dose of chlordiazepoxide (CDP) is able to modify the behavioral responses toward a predator odor was assessed in juvenile rats. Play behavior was suppressed and defensive behaviors were enhanced in the presence of a collar previously worn by a cat, when tested 24 hours later in the same context as that where the exposure occurred, and when tested in a context different than that in which the exposure occurred for up to 3 hours after exposure. CDP had no effect on the ability of cat odor to suppress play when rats were tested in …


Characterization Of The Behavioral And Neurochemical Effects Of Nicotine Withdrawal In Adolescent And Adult Rats., Luis Alberto Natividad Jan 2009

Characterization Of The Behavioral And Neurochemical Effects Of Nicotine Withdrawal In Adolescent And Adult Rats., Luis Alberto Natividad

Open Access Theses & Dissertations

Previous studies have demonstrated that the behavioral effects of nicotine withdrawal are lower in adolescent versus adult rats. However, the neurochemical mechanisms that mediate these developmental differences are presently unclear. Much work has shown that nicotine reward is mediated via enhanced dopamine neurotransmission in the mesolimbic pathway which originates in the ventral tegmental area (VTA) and terminates in several forebrain structures including the nucleus accumbens (NAcc). More recently, studies have shown that nicotine withdrawal produces a decrease in NAcc dopamine transmission, an effect that is believed to serve as a neurochemical marker of withdrawal in adult rodents. The goal of …