Synaptic connections among neurons that make up sensory pathways and other functional circuitries are the building blocks for how our brain functions, or in other words, how we see, hear, taste, move, learn, make plans or remember. These connections are amanable to change throughout life, allowing us to learn new skills, or to adapt to any external or internal alteration, including as we grow or age. By studying the morphological properties of neurons, synapses and identified axons, we aim to understand the synaptic inputs that converge on functionally distinct brain nuclei, how those inputs develop to form functional circuitries of the adult brain, and how they re-wire or degenerate.
What are the mechanisms by which the critical period of developmental plasticity is initiated, and terminated? Are there changes in the neurotransmitters, neuromodulators, hormones or their receptors that can signal for the changes in sensory perception or the behavior? How do glial cells interact with neurons in developing or aging brains? Using anatomical techniques including immuno-electron microscopy, ultrastructural morphometry, tract-tracing and confocal microscopy, we study synaptic circuitries in visual and gustatory sensory pathways during postnatal development, healthy adulthood and aging stages of our life span.
More to come: Morphology and Connectivity of Geniculate Relay Cell Dendrites and Synaptic Inputs in P14 Mice. Lead: Sydney Holton
Ultrastructural Neuropathology
Oligodendrocyte Dysregulation in Transgenic Alzheimer's Mice Models
Dysregulated oligodendrocyte and myelin dynamics as an early pathological feature of neuropil degeneration in Alzheimer's disease: an ultrastructural study. Erisir A, Maher EE, Anderson Z, Chawla S, Hanley L, Zhao A, Birisik K, Toklucu ES, Keskinoz EN.
I received an MD from Istanbul University School of Medicine in 1986 and a PhD in Behavioral Neuroscience from the State University of New York at Stony Brook in 1996. After my postdoctoral training at NYU Center for Neural Science and New York Medical School, Department of Physiology, I moved to the University of Virginia as an Assistant Professor in the Department of Psychology in 2000. I became a tenured Associate Professor in 2007 and Professor in 2013. I served as the director of undergraduate studies for the Cognitive Science (2008-2011) and the Neuroscience (2012-2015) programs, and as the Chairperson of my department (2016-2022).
My lab is equipped as a systems neuroanatomy, electron microscopy, quantitative morphology, and connectomics facility. The courses I teach at the undergraduate and the graduate level include Neural Mechanisms of Behavior (PSYC 4200); Psychobiology Lab (PSYC3210); Forum on Professional Conduct and Scientific Ethics (PSYC8040); Neural Mechanisms (PSYC7200); Neuropsychopharmacology (PSYC5285); Functional Neuroanatomy (PSYC5200); and Fundamentals of Neuroscience (PSYC 3200).
Contact Information
380A Gilmer Hall (office)
378/374 Gilmer Hall (lab)
We seek to develop techniques for high-resolution imaging of the tree shrew retina for visualizing and parameterizing retinal ganglion cell (RGC) axon bundles in vivo. We applied visible-light optical coherence tomography fibergraphy (vis-OCTF) and temporal speckle averaging (TSA) to visualize individual RGC axon bundles in the tree shrew retina. For the first time, we quantified individual RGC bundle width, height, and cross-sectional area and applied vis-OCT angiography (vis-OCTA) to visualize the retinal microvasculature in tree shrews. Throughout the retina, as the distance from the optic nerve head (ONH) increased from 0.5 mm to 2.5 mm, bundle width increased by 30%, height decreased by 67%, and cross-sectional area decreased by 36%. We also showed that axon bundles become vertically elongated as they converge toward the ONH. Ex vivo confocal microscopy of retinal flat-mounts immunostained with Tuj1 confirmed our in vivo vis-OCTF findings.
