Anatomy & Neurobiology Research Opportunities
Lisa Cooper, Ph.D., Hans Thewissen, Ph.D., Matthew Smith, Ph.D.
Neuron Counts in the Unusually Large Brains of Whales
Within mammals, dolphins and beluga whales are known to have a large brain size relative to body size. However, little is known of the composition of these brains. To increase our understanding of the different cells that make up the brains of terrestrial vs. marine mammals, this study aims to establish a fundamental understanding of the number of neurons in the brains of an echolocating and agile beluga whale compared to a slow move and non-echolocating bowhead whale. This study will use fluorescent labels to stain the neurons in the brains of both animals. Numbers of neurons will be counted using a confocal microscope. We hypothesize that the cerebellum of both animals will be roughly equal in their neuron density, but the cortex of the beluga brain will display a greater neuron density. Results will be compared with published accounts of neuron densities within terrestrial mammals (i.e., bats, elephants, carnivores, and ungulates). We expect our results will add a critical understanding of the architecture of big brains in cetaceans as well as elucidate the evolution of brains within aquatic and terrestrial mammals.
Tobin Hieronymus, Ph.D.
Digital Muscular and Fascial Anatomy Using Contrast-Enhanced MicroCT
Smooth muscle plays a critical role in the function of many organ systems, but our ability to understand the effects of smooth muscle contraction are limited by our current inability to directly record smooth muscle activity in-vivo. Unlike skeletal muscle, smooth muscle does not depend on cell-membrane depolarization to coordinate contraction, so standard techniques such as electromyography (EMG) will not work. Current research in Hieronymus lab is focused on two major aims: (1) applying established methods of measuring brain activity (calcium indicator fluorometry) to the novel setting of peripheral smooth muscle tissues to directly record activity, and (2) developing selective, localized, and reversible interventions to manipulate smooth muscle contraction for functional studies. This summer research project will make use of recent advances in microCT imaging to characterize the architecture of smooth muscle tissue in bird skin (our lab’s experimental model system for smooth muscle fluorometry and manipulation), with particular attention to its relationship to the superficial and deep fascia of the human-comparable musculoskeletal elements of the forelimb.
Julia Huyck, Ph.D.
Process underlying Immature Auditory Perception During Adolescence
Hearing and listening are critical to how adolescents communicate, learn new information, and engage with technology and culture; however, performance on auditory perceptual tasks takes a long time to become mature. Because few studies of auditory perception have centered on typically developing adolescents, little is known about the mechanisms underlying this immaturity. This project will evaluate the extent to which auditory stimulus encoding and various cognitive processes contribute to immature auditory perception during adolescence, using a combination of perceptual testing, neuropsychological and language testing, eye-tracking, and auditory evoked potentials (electrophysiology).
Jeffrey Mellott, Ph.D.
Age-related Loss of Neuropeptide Y inthe Auditory Midbrain and Hippocampus
Recent studies demonstrated that sensory processing deficits may be a precursor to pathologies such as Alzheimer’s Disease. Our long-term goal is to determine biomarkers that contribute to brain health across multiple nuclei as aging progresses from normal into pathological. Neuropeptide Y (NPY), a neurotransmitter that is co-released by GABAergic cells in the hippocampus and the inferior colliculus (IC) and, may be such a biomarker. In the hippocampus, NPY is considered neuroprotective as it can modulate oxidative stress, protect neurons from Aß neurotoxicity and prevent spatial memory loss. Recent studies of the IC have demonstrated that NPY is expressed exclusively in GABAergic cells and its receptors are expressed by glutamatergic cells, just as it is in the hippocampus. However, our understanding of age-related changes to NPY function in the IC serving as an early biomarker for functional changes in the hippocampus is inadequate due to the lack of information regarding how NPY expression and release occurs across the same time course of these two structures.
Jesse Young, Ph.D.
The Biomechanics of Arboreal Stability in Primates: An Integrated Analysis
Organismal biologists have long maintained a keen interest in the adaptations that allow some animals – such as primates – to successfully invade the small-branch arboreal niche, where maintaining stability is of paramount importance. Decades of comparative and experimental research have identified morphological features (e.g., clawless grasping extremities and long, mobile tails) and behavioral mechanisms (e.g., the maintenance of a low and flat center of mass and the use of distinctive gait patterns) that arguably facilitate stability on narrow and compliant substrates. Although these studies have greatly expanded our knowledge of primate locomotor adaptation and evolution, we nonetheless have an incomplete understanding of the mechanisms by which primates actually keep balance during arboreal locomotion. This research will remedy this gap in our understanding by testing a novel mechanical model that relates postcranial anatomy, grasping performance, and locomotor behavior to direct measures of balance performance on narrow substrates. Project research will focus on a previously collected dataset on locomotion in rhesus macaque monkeys (Macaca mulatta), in which synchronous kinematic, kinetic, and whole-body mechanical data during locomotion were measured during movement on simulated arboreal substrates. Analyses of these data will be compared with existing data on locomotor stability in squirrel monkeys (Saimiri boliviensis), marmoset monkeys (Callithrix jacchus), and gray tree squirrels (Sciurus carolinensis) to better understand the adaptive significance of typical primate morphology and quadrupedal locomotor behavior.
Ronald Seese, M.D., Ph.D.
Neural Circuits Implicated in Dysautonomia
Dysregulated autonomic function, or “dysautonomia”, is prevalent in many neuropsychiatric and neurodevelopmental disorders, including anxiety disorders and autism spectrum disorder. Dysautonomia may arise from a problem in how the central nervous system regulates the adrenal medulla. However, the neural circuits that control the adrenal medulla’s sympathetic output are not fully defined. Filling this fundamental gap in knowledge is crucial to understanding how the circuit may go awry in neuropsychiatric and neurodevelopmental disorders with prominent dysautonomia.
CONTACT
Nona Hose
Phone: 330.325.6499
Email: nhose@neomed.edu
These projects are funded by the Office of Research and Sponsored Programs (ORSP).
