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Direct Electrical Stimulation Of Prefrontal Cortex Modulates The Transient Heart Rate Response To Exercise In Conscious Humans, Bartek Kulas
Direct Electrical Stimulation Of Prefrontal Cortex Modulates The Transient Heart Rate Response To Exercise In Conscious Humans, Bartek Kulas
Electronic Thesis and Dissertation Repository
Prefrontal cortical regions play an essential role in generating appropriate cardiovascular adjustments, particularly in cardio-vagally mediated heart rate (HR) responses to active tasks. Functional imaging studies provide correlational evidence that this region coordinates HR responses to exercise, however, direct experimental evidence of prefrontal cortical HR regulation in humans is not available. Seven persons with epilepsy implanted with intracranial electroencephalography (iEEG) completed 2-second isometric handgrip (IHG) contractions at no-stimulation (NO-STIM) or sham-stimulation (SHAM) conditions, and during direct electrical stimulation (STIM) of the orbitofrontal and medial prefrontal cortex. HR responses to IHG during NO-STIM and SHAM increased HR by Δ4.9±2.7 bpm, compared …
Uncovering Deficits In Auditory Processing And Cognition Following Hearing Loss And Prefrontal Cortex Dysfunction, Krystyna B. Wieczerzak
Uncovering Deficits In Auditory Processing And Cognition Following Hearing Loss And Prefrontal Cortex Dysfunction, Krystyna B. Wieczerzak
Electronic Thesis and Dissertation Repository
How the auditory cortex and higher-order cortical regions, e.g., the prefrontal cortex, interact for accurate auditory processing and perception is not fully understood. Furthermore, although hearing loss is correlated with cognitive impairment, and animal studies have shown that loud noise exposure causes hippocampal neuropathology, the effects of noise-induced hearing loss on the medial prefrontal cortex (mPFC) and higher-level cognitive functions have not been well studied. Using electrophysiological and cognitive-behavioural testing in rats, Chapter 2 provides the first evidence of noise-induced plasticity in the mPFC (e.g., loss of functional connectivity with the auditory cortex) and deficits in stimulus-response habit learning. Although …
The Neuroprotective Effects Of Endurance Training On The Aging Brain, Katelyn Norton
The Neuroprotective Effects Of Endurance Training On The Aging Brain, Katelyn Norton
Electronic Thesis and Dissertation Repository
Dysregulation of autonomic control often develops with advancing age, favoring a chronic state of heightened sympathetic outflow with parasympathetic withdrawal. However, the mechanisms of this age-related autonomic impairment are not known and may relate to alterations in brain structure (e.g. cortical atrophy) and/or altered neural function, particularly in regions related to the cortical autonomic network, namely, the medial prefrontal cortex (MPFC), insula cortex (IC), and hippocampus (HC). Exercise exerts beneficial effects on brain structure and, in the case of cognition, neurologic function; however, how exercise affects regions of the brain related to autonomic function are not known. This thesis tested …
Circadian Rhythms In Reward And Underlying Neural Circuits, Ricardo M. Baltazar
Circadian Rhythms In Reward And Underlying Neural Circuits, Ricardo M. Baltazar
Electronic Thesis and Dissertation Repository
Studies suggest that the circadian timing system exerts an important influence on responses to rewarding stimuli. Diurnal rhythms in the rewarding value of amphetamine and mating behavior were observed, but differed in the pattern of their timing. Daily fluctuations in reward were correlated with oscillations in mesolimbic dopaminergic activity in both the nucleus accumbens (NAc) and ventral tegmental area (VTA), with a peak in NAc coinciding with the peak of sex reward, while the peak in the VTA associated with the peak in amphetamine reward. Also, rhythmic expression of the marker of neural activation, cFos, was observed in NAc, medial …