Biology Faculty: Greg Lnenicka

Greg A. Lnenicka

Professor of Biological Sciences
Ph.D., University of Virginia

Office LS1038
Telephone (518) 591-8812
Fax (518) 442-4767
Email gregl@albany.edu

Areas of Interest

  • Synaptic development and plasticity
  • Synaptic structure and function
  • Regulation of intracellular calcium




Research

Get PDF Synaptic connections between nerve cells establish the neural circuits that underlie behavior. An important feature of synapses is their modifiability by experience. In fact, it appears that the effect of experience on brain development and plasticity occurs largely at synapses. Specifically, synapses can be strengthened by increased use and this activity-dependent synapse strengthening plays an important role in the development of the brain, and in learning and memory in the adult. A major goal of Neuroscience is to understand the mechanisms of these synaptic changes. The complexity of the mammalian brain makes it difficult to study individual synapses. Thus, we have chosen to use the fruit fly (Drosophila) where single synapses can be studied and the activity and molecular components of these synapses can be altered using genetic techniques. We use imaging and electrophysiological techniques to examine changes in synaptic structure and function. A particular focus of our research is the role of intracellular calcium in synapse strengthening.
Synapses can be studied in Drosophila larvae. The synapses between neurons and muscle fibers in Drosophila larvae are ideal for these studies since these synapses are identifiable (the same synapse can be found in different animals), accessible and amenable to genetic manipulations. Dissection of a Drosophila larva (bottom) reveals the body-wall muscles (middle) where the identified synaptic terminals (top) are located.
Top: A nerve and its synapses are loaded with a fluorescent calcium indicator (OGB-1).
Right: Changes in intracellular calcium during synaptic transmission are detected by measuring the change in fluorescence. The change in fluorescence/initial fluorescence (ΔF/F0) along a synaptic terminal during a single action potential was mapped using pseudo-color. Images of the terminal were acquired at 50 Hz (20 msec exposure) beginning at the top and spanning 300 msec. The images show a rapid increase in ΔF/F0 followed by a slower decline. Pseudo-color calibration shows ΔF/F0. (From Lnenicka et al., 2006)

Research supported by National Science Foundation and National Institute of Health.

Publications

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  • He, T. and Lnenicka G.A. (2011) Ca2+ buffering at a Drosophila larval synaptic terminal. Synapse 65:687-693.
  • Desai S.A. and Lnenicka G.A. (2011) Characterization of postsynaptic Ca2+ signals at the Drosophila larval NMJ. J. Neurophysiol. 106(2):710-721.
  • Tsurudome K, Tsang K, Liao EH, Ball R, Penney J, Yang JS, Elazzouzi F, He T, Chishti A, Lnenicka G, Lai EC, Haghighi AP. (2010) The Drosophila miR-310 cluster negatively regulates synaptic strength at the neuromuscular junction. Neuron. 68(5):879-93.
  • He T, Hirsch HV, Ruden DM, Lnenicka GA (2009) Chronic lead exposure alters presynaptic calcium regulation and synaptic facilitation in Drosophila larvae. Neurotoxicology. 30:777-84.
  • Levin ED, Aschner M, Heberlein U, Ruden D, Welsh-Bohmer KA, Bartlett S, Berger K, Chen L, Corl AB, Eddins D, French R, Hayden KM, Helmcke K, Hirsch HV, Linney E, Lnenicka G, Page GP, Possidente D, Possidente B, Kirshner A (2009) Genetic aspects of behavioral neurotoxicology. Neurotoxicology. 30(5):741-53.
  • Hirsch HV, Possidente D, Averill S, Despain TP, Buytkins J, Thomas V, Goebel WP, Shipp-Hilts A, Wilson D, Hollocher K, Possidente B, Lnenicka G, Ruden DM. ( 2009) Variations at a quantitative trait locus (QTL) affect development of behavior in lead-exposed Drosophila melanogaster. Neurotoxicology. 30(2):305-11.
  • He T., Singh V., Rumpal N. and Lnenicka, G.A. (2009) Differences in Ca2+ regulation for high-output Is and low-output Ib motor terminals in Drosophila larvae. Neuroscience 159: 1283-91.
  • Feng X. Castracane, J. Tokranova, N. Gracias, A. Lnenicka, G. and Szaro, B.G. (2007) A living cell-based biosensor utilizing G-protein coupled receptors: Principles and detection methods. Biosensors and Bioelectronics 22:3230-3237.
  • Harrisingh M.C., Ying W., Lnenicka G.A., and Nitabach M.N. (2007) Intracellular Ca2+ regulates free-running circadian clock oscillation in vivo. J. Neuroscience 27:12489-12499.
  • Lnenicka, G.A., Theriault, K., and Monroe, R. (2006) Sexual differentiation of identified motor terminals in Drosophila larvae. J Neurobiol., 66(5):488-498.
  • Lnenicka G.A., Grizzaffi J., Lee B. and Rumpal N. (2006) Ca2+ dynamics along identified synaptic terminals in Drosophila larvae. J. Neurosci. 26:12283-12293.
  • Lnenicka, G.A., Spencer, G.M. and Keshishian, H. (2003) Effect of reduced impulse activity on the development of identified motor terminals in Drosophila larvae. J. Neurobiol. 54(2):337-345.
  • Morley, E.J., Hirsch, H., Hollocher, K. and Lnenicka G.A. (2003) Effects of chronic lead exposure on the neuromuscular junction in Drosophila larvae. Neurotoxicology 24(1):35-41.
  • Rumpal, N. and Lnenicka, G.A. (2003) Mechanisms of calcium clearance from growth cones generated by crayfish phasic and tonic motor axons. J. Neurophysiol. 89:3225-3234.
  • Pearce, J., Lnenicka, G.A. and Govind C.K. (2003) Regenerating crayfish motor axons assimilate glial cells and sprout in cultured explants. J. Comp. Neurol. 464: 449-462.
  • Fengler, B.T. and Lnenicka, G.A. (2002) Activity-dependent plasticity of calcium clearance from crayfish motor axons. J. Neurophysiol. 87(3): 1625-1628.
  • Lnenicka, G.A. and Morley, E.J. (2001) Activity-dependent development and plasticity of crustacean motor terminals. In “The Crustacean Nervous System.” Konrad Wiese (Ed.) Springer Verlag, Berlin Heidelberg New York.
  • Lnenicka, GA and Keshishian, H (2000) Identified motor terminals in Drosophila Larvae show distinct differences in morphology and physiology. J. Neurobiology 43:186-197.