Allometric Scaling of Brain, Brain Components and Neurons with Body Size of Social Bees
Entomology and Insect Science
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PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
EmbargoRelease after 24-Feb-2017
AbstractAnimals in general vary immensely in body size, which greatly affects their morphology, physiology, survival, and nutritional requirements. The nervous system is also affected by variation in body size, which, in turn, shapes the perception of environmental stimuli and the behavior of animals. Comparative studies of vertebrates suggest that larger brains and their integrative centers comprise more and generally larger neurons (Jerison, 1973; Kaas, 2000), but much less is known about brain - body size relations in invertebrates. Closely related social bee species are well suited to study correlations between body size and brain composition. Different honey bee species vary in body size yet differ little in their ecological requirements and behavior and bumble bees feature a large range of body sizes even within a single colony.
Degree ProgramGraduate College
Entomology and Insect Science
Degree GrantorUniversity of Arizona
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Blue-Light Therapy following Mild Traumatic Brain Injury: Effects on White Matter Water Diffusion in the BrainBajaj, Sahil; Vanuk, John R.; Smith, Ryan; Dailey, Natalie S.; Killgore, William D. S.; Univ Arizona, Dept Psychiat, Coll Med, SCAN Lab (FRONTIERS MEDIA SA, 2017-11-22)Mild traumatic brain injury (mTBI) is a common and often inconspicuous wound that is frequently associated with chronic low-grade symptoms and cognitive dysfunction. Previous evidence suggests that daily blue wavelength light therapy may be effective at reducing fatigue and improving sleep in patients recovering from mTBI. However, the effects of light therapy on recovering brain structure remain unexplored. In this study, we analyzed white matter diffusion properties, including generalized fractional anisotropy, and the quantity of water diffusion in isotropic (i.e., isotropic diffusion) and anisotropic fashion (i.e., quantitative anisotropy, QA) for fibers crossing 11 brain areas known to be significantly affected following mTBI. Specifically, we investigated how 6 weeks of daily morning blue light exposure therapy (compared to an amber-light placebo condition) impacted changes in white matter diffusion in individuals with mTBI. We observed a significant impact of the blue light treatment (relative to the placebo) on the amount of water diffusion (QA) for multiple brain areas, including the corpus callosum, anterior corona radiata, and thalamus. Moreover, many of these changes were associated with improvements in sleep latency and delayed memory. These findings suggest that blue wavelength light exposure may serve as one of the potential non-pharmacological treatments for facilitating structural and functional recovery following mTBI; they also support the use of QA as a reliable neuro-biomarker for mTBI therapies.
The bidirectional gut-brain-microbiota axis as a potential nexus between traumatic brain injury, inflammation, and diseaseSundman, Mark H.; Chen, Nan-kuei; Subbian, Vignesh; Chou, Ying-hui; Department of Psychology, University of Arizona, Tucson, AZ, USA (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2017-11)As head injuries and their sequelae have become an increasingly salient matter of public health, experts in the field have made great progress elucidating the biological processes occurring within the brain at the moment of injury and throughout the recovery thereafter. Given the extraordinary rate at which our collective knowledge of neurotrauma has grown, new insights may be revealed by examining the existing literature across disciplines with a new perspective. This article will aim to expand the scope of this rapidly evolving field of research beyond the confines of the central nervous system (CNS). Specifically, we will examine the extent to which the bidirectional influence of the gut-brain axis modulates the complex biological processes occurring at the time of traumatic brain injury (TBI) and over the days, months, and years that follow. In addition to local enteric signals originating in the gut, it is well accepted that gastrointestinal (GI) physiology is highly regulated by innervation from the CNS. Conversely, emerging data suggests that the function and health of the CNS is modulated by the interaction between 1) neurotransmitters, immune signaling, hormones, and neuropeptides produced in the gut, 2) the composition of the gut microbiota, and 3) integrity of the intestinal wall serving as a barrier to the external environment. Specific to TBI, existing pre-clinical data indicates that head injuries can cause structural and functional damage to the GI tract, but research directly investigating the neuronal consequences of this intestinal damage is lacking. Despite this void, the proposed mechanisms emanating from a damaged gut are closely implicated in the inflammatory processes known to promote neuropathology in the brain following TBI, which suggests the gut-brain axis may be a therapeutic target to reduce the risk of Chronic Traumatic Encephalopathy and other neurodegenerative diseases following TBI. To better appreciate how various peripheral influences are implicated in the health of the CNS following TBI, this paper will also review the secondary biological injury mechanisms and the dynamic pathophysiological response to neurotrauma. Together, this review article will attempt to connect the dots to reveal novel insights into the bidirectional influence of the gut-brain axis and propose a conceptual model relevant to the recovery from TBI and subsequent risk for future neurological conditions.
Challenges to Secondary Brain Injury Prevention in Severe Traumatic Brain InjuryKeller, Kristen Jo (The University of Arizona., 2014)BACKGROUND/AIMS: Inconsistency in the use of secondary brain injury prevention guidelines among US trauma centers after severe traumatic brain injury is prevalent in many literature sources. However, this phenomenon has not been thoroughly studied. The purpose of this DNP project is to identify the key barriers and challenges in compliance to the evidence-based guidelines for secondary brain injury prevention. DESIGN: An exploratory, emergent design was used to collect descriptive qualitative data through the use of a survey. SETTING: Six Phoenix Metropolitan Level 1 trauma centers. PARTICIPANTS: All survey participants who consented to survey completion, which had greater than six months of experience and directly worked with patients suffering from a severe TBI in the clinical setting. MEASUREMENTS: Participant demographics (work experience, area of work, job title), current awareness and use of Brain Trauma Foundation guidelines, and time duration for evidence based order set implementation. Narrative responses were also used to identify barriers to current use of the BTF guidelines and factors that may promote their use in the future. RESULTS: A total of 43 participants consented to the survey study, with completion by 35 participants. RNs (n=27), Physicians (n=2), NPs or PAs (n=5), with an average work experience of 6 to 14 years (42.86%). A total of n=22 (62%) of participants were unaware of the current BTF guidelines for severe TBI and only 25% (n=9) aware that their facility has a protocol based on the BTF guidelines for severe TBI, while 51% (n=18) were unsure if their facility had a protocol. Barriers were identified in narrative form and were consistent with awareness/education, provider congruence, communication, and order set/protocol process improvement. CONCLUSION: The understanding of current patient management for severe TBI based on the BTF guidelines is sporadic among the greater Phoenix area Level 1 trauma centers. Requiring proof of BTF guidelines compliance by the ACS at time of Level 1 certification may increase the consistent recommended use of the BTF guidelines for the care of severe TBIs.