Associate Professor of Biological Sciences
PhD, 2001 University of Illinois at Urbana-Champaign
Electrophysiology and molecular biology of neural plasticity and stability
Research descriptionUltimately, all nervous system output relies on each individual neuron producing the correct responses to synaptic input. Intrinsic excitability refers to the propensity of a neuron to fire action potentials when exposed to such an input signal. In other words, the intrinsic excitability of neurons is responsible for the translation of synaptic input to the particular output function of a given neuron. Neuronal excitability is directly attributable to the suite of ion channels inserted into the membrane of the cell, as well as the biochemical properties and kinetics of those channels. Because of their fundamental role in generating neuronal output, it is not surprising that alterations in the properties, spatial distribution, or abundance of these ion channels can result in considerable plasticity for neurons and the networks to which they belong.
Our lab focuses on how plasticity and stability are balanced in individual neurons by studying the molecular regulation of ion channel proteins and how this influences neuronal excitability. Using cutting edge electrophysiology and molecular biology techniques, we are able to measure the gene expression of multiple ion channels in single neurons of a rhythmic motor network called the stomatogastric ganglion (STG). By studying these cells in the STG network, we can investigate not only the effects at the single cell level, but also the influence that changes in single neurons has on the network activity as a whole.
This work has implications not only for understanding how networks maintain functional output, but also what goes wrong when these networks fail, as is the case with some diseases which affect the circuitry of the brain and spinal cord.
Garcia, V.J., Daur, N., Temporal, S., Schulz, D.J., Bucher, D., (2015) Neuropeptide receptor transcript expression levels and magnitude of ionic current responses show cell type- specific differences in a small motor circuit. Journal of Neuroscience, 35:6786-6800.
Garcia, V.J., Daur, N., Temporal, S., Schulz, D.J., and Bucher, D. (2015). Neuropeptide receptor transcript expression levels and magnitude of ionic current responses show cell type- specific differences in a small motor circuit. Journal of Neuroscience 35, 6786-6800.
Villalon E, Schulz DJ, Waters ST (2014) Real-time PCR quantification of gene expression in embryonic mouse tissue. Methods in Molecular Biology 1092: 81-94.
Shruti S, Schulz DJ, Lett KM, Marder E (2014) Electrical coupling and innexin expression in the stomatogastric ganglion of the crab Cancer borealis. Journal of Neurophysiology 112: 2946-2958.
Garcia VB, Garcia ML, Schulz DJ (2014) Quantitative expression profiling in mouse spinal cord reveals changing relationships among channel and receptor mRNA levels across postnatal maturation. Neuroscience 277C: 321-333.
Temporal S, Lett KM, Schulz DJ (2014) Activity-dependent feedback regulates correlated ion channel mRNA levels in single identified motor neurons. Current Biology 24: 1899-1904.
Ransdell JL, Nair SS, Schulz DJ (2013) Neurons within the same network independently achieve conserved output by differentially balancing variable conductance magnitudes. Journal of Neuroscience 33: 9950-9956.
Ransdell JL, Temporal S, West NL, Leyrer ML, Schulz DJ (2013) Characterization of inward currents and channels underlying burst activity in motor neurons of the crab cardiac ganglion. Journal of Neurophysiology 110:42-54.
Ransdell JL, Nair SS, Schulz DJ (2012) Rapid homeostatic plasticity of intrinsic excitability in a central pattern generator network stabilizes functional neural network output. Journal of Neuroscience 32: 9649-9658
Nahar J, Lett KM, Schulz DJ (2012) Restoration of descending inputs fails to rescue activity following deafferentation of a motor network. Journal of Neurophysiology 108: 871-881.
Barry DM, Stevenson W, Bober BG, Wiese PJ, Dale JM, Barry GS, Byers NS, Strope JD, Chang R, Schulz DJ, Shah S, Calcutt NA, Gebremichael Y, Garcia ML (2012) Expansion of neurofilament medium C terminus increases axonal diameter independent of increases in conduction velocity or myelin thickness. Journal of Neuroscience 32: 6209-6219
Temporal S, Desai M, Khorkova O, Varghese G, Dai A, Schulz DJ, Golowasch J (2012) Neuromodulation independently determines correlated channel expression and conductance levels in motor neurons of the stomatogastric ganglion. Journal of Neurophysiology 107: 718- 727.
Oct. 10, 2014
New study finds that neurons actively “fine tune” themselves at the genetic level
July 1, 2013
Study by Schulz lab shows nerve cells can work in different ways with same result
May 23, 2013
Schulz lab receives grant to conduct genetic study of Missouri crayfish
July 30, 2009
Biologist finds flexibility in nerve cell construction