Questioning The Modality Of The Occipital Lobe

This dissertation explores the occipital lobe’s response to non-visual inputs, and whether this responsivity partitions into separate localization and identification pathways as seen with visual inputs. We hypothesized that occipital areas may merely prefer visual inputs, while maintaining similar task-based sensory recruitment in response to other senses. Our secondary hypothesis was that the robust occipital activation seen in late-blind participants stems at least initially from standard connections present even in the typically sighted, and that these standard connections are functionally utilized by the typically sighted in spatially relevant non-visual analyses. Our initial literature review supported our hypotheses that the occipital lobe is a highly plastic, cross-modally responsive area and that recruitment of occipital areas in the blind stems from the strengthening of existing multi-modal connections. To further explore our topic, we conducted meta-analyses on fMRI and PET studies reporting occipital response to non-visual input in congenital/early-blind participants and/or blindfolded but otherwise typically sighted participants. Through these analyses, we noted significant extrastriate activations for blind participants beyond that seen with sighted participants, which lent support to our task-based wiring hypothesis. We also observed common activations between blind and sighted participants, notably including activation in striate cortex, which supported the notion of functional connections to occipital lobe from other sensory inputs regardless of the presence or lack of visual input. Finally, we conducted an fMRI study investigating the effects of short-term blindfolding on occipital responsivity to auditory stimuli in typically sighted participants. We did not observe greater activation in participants blindfolded for 45 minutes than we observed with non-blindfolded participants, but our study did further highlight the functional connections present between non-visual senses and the occipital lobe, and again supported our task-based wiring hypothesis. Overall, we found support for the occipital lobe being multi-modally reactive, even in typically sighted individuals. We also found evidence of task-based wiring being maintained regardless of the sensory modality being responded to, and of the likelihood that these functional non-visual connections are at least initially what give rise to the widespread occipital activation observed with blind participants in response to non-visual stimuli

Neural Biomarkers for Assessing Different Types of Imagery in Pictorial Health Warning Labels for Cigarette Packaging: A Cross-Sectional Study

Objective Countries around the world have increasingly adopted pictorial health warning labels (HWLs) for tobacco packages to warn consumers about smoking-related risks. Research on how pictorial HWLs work has primarily analysed self-reported responses to HWLs; studies at the neural level comparing the brain\u27s response to different types of HWLs may provide an important complement to prior studies, especially if self-reported responses are systematically biased. In this study we characterise the brain\u27s response to three types of pictorial HWLs for which prior self-report studies indicated different levels of efficacy. Methods Current smokers rated pictorial HWLs and then observed the same HWLs during functional MRI (fMRI) scanning. Fifty 18–50-year-old current adult smokers who were free from neurological disorders were recruited from the general population and participated in the study. Demographics, smoking-related behaviours and self-reported ratings of pictorial HWL stimuli were obtained prior to scanning. Brain responses to HWLs were assessed using fMRI, focusing on a priori regions of interest. Results Pictorial HWL stimuli elicited activation in a broad network of brain areas associated with visual processing and emotion. Participants who rated the stimuli as more emotionally arousing also showed greater neural responses at these sites. Conclusions Self-reported ratings of pictorial HWLs are correlated with neural responses in brain areas associated with visual and emotional processing. Study results cross-validate self-reported ratings of pictorial HWLs and provide insights into how pictorial HWLs are processed

Soil Failure Characteristics Caused by an Oscillating Tillage Tool and Bulldozer Blade

122 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1973.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD

Nitric oxide regulates cardiac intracellular Na(+) and Ca(2+) by modulating Na/K ATPase via PKCε and phospholemman-dependent mechanism

AbstractIn the heart, Na/K-ATPase regulates intracellular Na+ and Ca2+ (via NCX), thereby preventing Na+ and Ca2+ overload and arrhythmias. Here, we test the hypothesis that nitric oxide (NO) regulates cardiac intracellular Na+ and Ca2+ and investigate mechanisms and physiological consequences involved. Effects of both exogenous NO (via NO-donors) and endogenously synthesized NO (via field-stimulation of ventricular myocytes) were assessed in this study. Field stimulation of rat ventricular myocytes significantly increased endogenous NO (18±2μM), PKCε activation (82±12%), phospholemman phosphorylation (at Ser-63 and Ser-68) and Na/K-ATPase activity (measured by DAF-FM dye, western-blotting and biochemical assay, respectively; p<0.05, n=6) and all were abolished by Ca2+-chelation (EGTA 10mM) or NOS inhibition l-NAME (1mM). Exogenously added NO (spermine-NONO-ate) stimulated Na/K-ATPase (EC50=3.8μM; n=6/grp), via decrease in Km, in PLMWT but not PLMKO or PLM3SA myocytes (where phospholemman cannot be phosphorylated) as measured by whole-cell perforated-patch clamp. Field-stimulation with l-NAME or PKC-inhibitor (2μM Bis) resulted in elevated intracellular Na+ (22±1.5 and 24±2 respectively, vs. 14±0.6mM in controls) in SBFI-AM-loaded rat myocytes. Arrhythmia incidence was significantly increased in rat hearts paced in the presence of l-NAME (and this was reversed by l-arginine), as well as in PLM3SA mouse hearts but not PLMWT and PLMKO. We provide physiological and biochemical evidence for a novel regulatory pathway whereby NO activates Na/K-ATPase via phospholemman phosphorylation and thereby limits Na+ and Ca2+ overload and arrhythmias. This article is part of a Special Issue entitled “Na+ Regulation in Cardiac Myocytes”