Research in the Glowatzki Lab focuses on the auditory system, with a particular focus on synaptic transmission in the inner ear. Our lab is using dendritic patch clamp recordings to examine mechanisms of synaptic transmission at this first, critical synapse in the auditory pathway. With this technique, we can diagnose the molecular mechanisms of transmitter release at uniquely high resolution (this is the sole input to each afferent neuron), and relate them directly to the rich knowledge base of auditory signaling by single afferent neurons. We study pre- and post-synaptic mechanisms that determine auditory nerve fiber properties. This approach will help to study general principles of synaptic transmission and specifically to identify the molecular substrates for inherited auditory neuropathies and other cochlear dysfunctions.

The Brown Lab is focused on the function of the cerebral cortex in the brain, which underlies our ability to interact with our environment through sensory perception and voluntary movement. Our research takes a bottom-up approach to understanding how the circuits of this massively interconnected network of neurons are functionally organized, and how dysfunction in these circuits contributes to neurodegenerative diseases like amyotrophic lateral sclerosis and neuropsychiatric disorders, including autism and schizophrenia. By combining electrophysiological and optogenetic approaches with anatomical and genetic techniques for identifying cell populations and pathways, the Brown Lab is defining the synaptic interactions among different classes of cortical neurons and determining how long-range and local inputs are integrated within cortical circuits. In amyotrophic lateral sclerosis, corticospinal and spinal motor neurons progressively degenerate. The Brown Lab is examining how abnormal activity within cortical circuits contributes to the selective degeneration of corticospinal motor neurons in an effort to identify new mechanisms for treating this disease. Abnormalities in the organization of cortical circuits and synapses have been identified in genetic and anatomical studies of neuropsychiatric disease. We are interested in the impact these abnormalities have on cortical processing and their contribution to the disordered cognition typical of autism and schizophrenia.

The Dong Laboratory has identified many genes specifically expressed in primary sensory neurons in dorsal root ganglia (DRG). Our lab uses multiple approaches, including molecular biology, mouse genetics, mouse behavior and electrophysiology, to study the function of these genes in pain and itch sensation. Other research in the lab examines the molecular mechanism of how skin mast cells sensitize sensory nerves under inflammatory states.

The Bergles Laboratory studies synaptic physiology, with an emphasis on glutamate transporters and glial involvement in neuronal signaling. We are interested in understanding the mechanisms by which neurons and glial cells interact to support normal communication in the nervous system. The lab studies glutamate transport physiology and function. Because glutamate transporters play a critical role in glutamate homeostasis, understanding the transporters' function is relevant to numerous neurological ailments, including stroke, epilepsy, and neurodegenerative diseases like amyotrophic lateral sclerosis (ALS). Other research in the laboratory focuses on signaling between neurons and glial cells at synapses. Understanding how neurons and cells communicate, may lead to new approaches for stimulating re-myelination following injury or disease. Additional research in the lab examines how a unique form of glia-to-neuron signaling in the cochlea influences auditory system development, whether defects in cell communication lead to certain hereditary forms of hearing impairment, and if similar mechanisms are related to sound-induced tinnitus.

The Veit Stuphorn Laboratory studies the neurophysiological mechanisms that underlie decision making and self-control. We record the activity of single neurons in awake animals that are engaged in decision-making processes. This allows us to identify the types of signals that neurons in specific parts of the brain represent and the computations they carry out. We also study human subjects in the same tasks with the help of fMRI. These parallel experiments provide comparative information about decision processes in human and non-human primates.

In the Lee Martin Laboratory, we are testing the hypothesis that selective vulnerability--the phenomenon in which only certain groups of neurons degenerate in adult onset neurological disorders like amyotrophic lateral sclerosis and Alzheimer's disease--is dictated by brain regional connectivity, mitochondrial function and oxidative stress. We believe it is mediated by excitotoxic cell death resulting from abnormalities in excitatory glutamatergic signal transduction pathways, including glutamate transporters and glutamate receptors as well as their downstream intracellular signaling molecules. We are also investigating the contribution of neuronal/glial apoptosis and necrosis as cell death pathways in animal (including transgenic mice) models of acute and progressive neurodegeneration. We use a variety of anatomical and molecular neurobiological approaches, including neuronal tract-tracing techniques, immunocytochemistry, immunoblotting, antipeptide antibody production, transmission electron microscopy and DNA analysis to determine the precise regional and cellular vulnerabilities and the synaptic and molecular mechanisms that result in selective neuronal degeneration.

The Wolfgang Laboratory is interested in understanding the metabolic properties of neurons and glia at a mechanistic level in situ. Some of the most interesting, enigmatic and understudied cells in metabolic biochemistry are those of the nervous system. Defects in these pathways can lead to devastating neurological disease. Conversely, altering the metabolic properties of the nervous system can have surprisingly beneficial effects on the progression of some diseases. However, the mechanisms of these interactions are largely unknown. We use biochemical and molecular genetic techniques to study the molecular mechanisms that the nervous system uses to sense and respond to metabolic cues. We seek to understand the neurometabolic regulation of behavior and physiology in obesity, diabetes and neurological disease. Current areas of study include deconstructing neurometabolic pathways to understand the biochemistry of the nervous system and how these metabolic pathways impact animal behavior and physiology, metabolic heterogeneity and the evolution of metabolic adaptation.

Our laboratory conducts basic and translational research aimed at better understanding the pathogenesis of multiple sclerosis (MS) and the role of the immune system in CNS disease, particularly the processes that drive progressive disability such as neurodegeneration and remyelination failure. We currently have three parallel research programs: 1. Metabolism as a modulator of MS: We are studying how basic metabolic pathways regulate the immune system and how these pathways might be exploited to protect neurons and myelin-forming oligodendrocytes from injury. 2. Identifying pathways by which nitric oxide (NO) and other free radicals cause neuronal and axonal damage. Our lab is identifying specific signaling pathways initiated by NO and other free radicals that can be targeted by drugs to produce neuroprotection. 3. Modulating the innate immune system in MS: In collaboration with others at Johns Hopkins, we are studying ways to enhance the reparative functions of microglia while preventing maladaptive responses. This work has identified bryostatin-1 as a potential drug that may be re-purposed for this task.

Dr. Fridman's research group invents and develops bioelectronics for Neuroengineering and Medical Instrumentation applications. We develop innovative medical technology and we also conduct the necessary biological studies to understand how the technology could be effective and safe for people. Our lab is currently focused on developing the ""Safe Direct Current Stimulation"" technology, or SDCS. Unlike the currently available commercial neural prosthetic devices, such as cochlear implants, pacemakers, or Parkinson's deep brain stimulators that can only excite neurons, SDCS can excite, inhibit, and even sensitize them to input. This new technology opens a door to a wide range of applications that we are currently exploring along with device development: e.g. peripheral nerve stimulation for suppressing neuropathic pain, vestibular nerve stimulation to correct balance disorders, vagal nerve stimulation to suppress an asthma attack, and a host of other neuroprosthetic applications. Medical Instrumentation MouthLab is a ""tricorder"" device that we invented here in the Machine Biointerface Lab. The device currently obtains all vital signs within 60s: Pulse rate, breathing rate, temperature, blood pressure, blood oxygen saturation, electrocardiogram, and FEV1 (lung function) measurement. Because the device is in the mouth, it has access to saliva and to breath and we are focused now on expanding its capability to obtaining measures of dehydration and biomarkers that could be indicative of a wide range of internal disorders ranging from stress to kidney failure and even lung cancer.

The research conducted in the Mumm Lab (Dept. of Ophthalmology, Wilmer Eye Institute) is focused on understanding how neural circuits are formed, how they function, and how they can be regenerated, to develop new therapies for retinal regeneration. Toward that end, we investigate the development, function, and regeneration of disease-relevant neurons and neural circuits responsible for vision. An emphasis is placed on translating what can be learned in regenerative model systems to develop novel therapies for stimulating dormant regenerative capacities in humans, Therefore, we apply what we learn from a naturally regenerative species, the zebrafish, toward the development of novel therapies for restoring visual function to patients. We place an emphasis on unique perspectives zebrafish afford to biological studies, such as in vivo time-lapse imaging of cellular behaviors and cell-cell interactions, and high-throughput chemical and genetic screening. We have pioneered several technologies to support this work including multicolor imaging of neural circuit formation, a selective cell ablation methodology, and a quantitative high-throughput phenotypic screening platform. Together, these approaches are providing novel insights into how the degeneration and regeneration of discrete retinal cell types is controlled.