Developmental and Regenerative Neurobiology

Research Description

Topic 1. Mechanisms underlying dopamine neurogenesis
The floor plate, the ventral organizing center in the embryonic neural tube, patterns the neural tube by secreting the potent morphogen Shh. Using genetic fate mapping, we have recently shown that the midbrain floor plate, unlike the hindbrain and spinal cord floor plate, is neurogenic and is the source of midbrain dopamine neurons (Joksimovic, et al, 2009 Nature Neuroscience, Joksimovic et al. 2009 PNAS). We are interested in understanding pathways that are involved in floor plate neurogenesis and production of dopamine neurons. We have shown that Wnt signaling is critical for the establishment of the dopamine progenitor pool and that miRNAs may modulate the dosage and timing of the Wnt pathway (Anderegg et al, PloS Genetics 2013).

Topic 2. Deconstructing Dopaminergic Diversity
The neurotransmitter dopamine, produced mainly by midbrain dopaminergic neurons, influences a spectrum of behaviors including motor, learning, reward, motivation and cognition. In accordance with its diverse functions, dopaminergic dysfunction is implicated in a range of disorders affecting millions of people, including Parkinson’s disease (PD), schizophrenia, addiction and depression. How a small group of neurons underpins a gamut of key behaviors and diseases remains enigmatic. We postulated that there must exist several molecularly distinct dopaminergic neuron populations that, in part, can account for the plethora of dopaminergic functions and disorders. We are currently working to test this hypothesis and define dopamine neuron subtypes.

Topic 3. MicroRNAs in Schwann cell (SC) differentiation
MicroRNAs, by modulating gene expression, have been implicated as regulators of various cellular and physiological processes including differentiation, proliferation and cancer. We have studied the role of microRNAs in Schwann cell (SC) differentiation by conditional removal of the microRNA processing enzyme, Dicer1 (Yun et al, 2010, J Neurosci) . We reveal that mice lacking Dicer1 in SC (Dicer1 cKO) display a severe neurological phenotype resembling congenital hypomyelination. SC lacking Dicer1 are stalled in differentiation at the promyelinating state and fail to myelinate axons. We are beginning to determine the molecular basis of this phenotype. Understanding this will be important not only for congenital hypomyelination, but also for peripheral nerve regeneration and SC cancers.

For more information, please see Dr. Awatramani's faculty profile.

Publications

View Dr. Awatramani's complete list of publications in PubMed.

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Rajeshwar Awatramani, PhD at 312-503-0690

Research Description

The Kessler Laboratory focuses on the biology of neural stem cells and growth factors and their potential for regenerating the damaged or diseased nervous system. A major interest of the laboratory has been the role of bone morphogenetic protein (BMP) signaling in both neurogenesis and gliogenesis and in regulating cell numbers in the developing nervous system.  Both multipotent neural stem cells and pluripotent embryonic stem cells are studied in the laboratory. Recent efforts have emphasized studies of human embryonic stem cells (hESC) and human induced pluripotent stem cells (hIPSC). The Kessler lab oversees the Northwestern University ESC and IPSC core and multiple collaborators use the facility. In addition to the studies of the basic biology of stem cells, the laboratory seeks to develop techniques for promoting neural repair in animal models of spinal cord injury and stroke. In particular, the lab is examining how stem cells and self-assembling peptide amphiphiles can be used together to accomplish neural repair. The lab is also using hIPSCs to model Alzheimer’s disease and other disorders. 

For more information see the faculty profile of John Kessler, MD.

Publications

View Dr. Kessler's full list of publications in PubMed.

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