Medicine and Health Sciences Commons^™

Exploring The Neural Basis Of Top-Down Guided Action In Macaque Monkeys, Jessica M. Phillips

Electronic Thesis and Dissertation Repository

To thoroughly characterize any brain mechanism requires an appropriate animal model for invasive studies. An invaluable model system used toward a comprehension of cognitive neurophysiology is the macaque monkey. It is important to delineate similarities and limitations for this model in relation to the human brain and cognition. In this thesis, we have thus conducted three experiments to investigate putative generalizations between monkeys and humans regarding the neural processes associated with top-down action control in monkeys.

Our daily behaviour is largely comprised of automatic routine actions. The frequent repetition of certain behaviours in response to particular contexts can give rise …

An Investigation Into The Combined Effects Of Β-Amyloid Toxicity And Cerebral Ischemia On The Pathological Expression Of Gangliosides., Jeffrey D. Hepburn

Electronic Thesis and Dissertation Repository

Identifying mechanisms underlying the synergistic pathological interaction between stroke and Alzheimer’s disease (AD) can effectively guide future therapeutic strategies for these highly co-morbid conditions. Aberrant ganglioside expression marked by the pathological accumulation of ganglioside GM3 is common to stroke and AD, yet it is unclear whether GM3 is synergistically enhanced in a comorbid model, or if GM3 is a viable therapeutic target. Adult male Wistar rats received a unilateral ischemic striatal infarct via endothelin-1 (ET-1) injection alone or in combination with bilateral intracerebroventricular injection of the β-Amyloid 25-35 peptide (Aβ) to induce generalized Aβ toxicity (Aβ/ET-1). Animals were sacrificed after …

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, …

Familiality Of Auditory Evoked Potentials: Preliminary Investigation Of The Auditory Brainstem Response And Late Latency Cortical Response, Matthew B. Lucas

Electronic Thesis and Dissertation Repository

Twenty-four participants, consisting of six sibling pairs and six non-sibling pairs, participated in this study investigating the familiality of auditory evoked potentials (AEPs). The auditory brainstem response (ABR) recorded at high stimulus rates, revealed that Wave V latency increases, while amplitude decreases as stimulus rate increases. ABR Wave V latency was also found to increase with click position within a stimulus train, plateauing by the third stimulus. No evidence for familiality was found with respect to the ABR Wave V under these conditions. The late latency response (LLR) components N1 and P2 were found to decrease between the first and …

Effects Of Methamphetamine On Sexual Behavior, Karla S. Frohmader

Electronic Thesis and Dissertation Repository

Methamphetamine (Meth) is a highly addictive psychostimulant associated with enhanced sexual desire, arousal, and sexual pleasure. Moreover, Meth abuse is frequently linked with the practice of sexual risk behavior and increased prevalence of Human Immunodeficiency Virus (HIV). Currently, the neurobiological basis for this drug-sex nexus is unknown. Moreover, there is a lack of studies investigating the effects of Meth on sexual behavior and more importantly, compulsive sex-seeking behavior, under controlled experimental settings in animal models. First, using immuhistochemistry for mating- and Meth-induced neural activation it was demonstrated that Meth administration in male rats activates neurons in brain regions of the …

Decoding Motor Intentions From Human Brain Activity, Jason P. Gallivan

Electronic Thesis and Dissertation Repository

“You read my mind.” Although this simple everyday expression implies ‘knowledge or understanding’ of another’s thinking, true ‘mind-reading’ capabilities implicitly seem constrained to the domains of Hollywood and science-fiction. In the field of sensorimotor neuroscience, however, significant progress in this area has come from mapping characteristic changes in brain activity that occur prior to an action being initiated. For instance, invasive neural recordings in non-human primates have significantly increased our understanding of how highly cognitive and abstract processes like intentions and decisions are represented in the brain by showing that it is possible to decode or ‘predict’ upcoming sensorimotor …