Leonid Moroz
(Ph.D., Institute of Developmental
Biology, Academy of Sciences,
Moscow, Russia, 1989)

Professor of Neuroscience, Zoology and Chemistry

moroz@whitney.ufl.edu

Genomic Bases of Neuronal Identity and Plasticity

Our laboratory works to characterize basic mechanisms underlying the design of nervous systems and evolution of neuronal signaling mechanisms. The major questions are: (1) why are individual neurons so different from each other, (2) how do they maintain such precise connections between each other, (3) how does this fixed wiring result in such enormous neuronal plasticity and (4) how does this contribute to learning and memory mechanisms? By taking advantage of relatively simpler nervous systems of invertebrate animals as models, we conbine neuroscience,genomics, bioinformatics, evolutionary theory, zoology, molecular biology, microanalytical chemistry and nanoscience to understand how neurons operate, remember and learn.

Current Projects

As part of the NIH Center of Excellence in Genomic Sciences, our first project investigates the genomic basis of neuronal identity and plasticity. Due to the tremendous difficulties in mapping single cells and processes in the mammalian brain, we study the giant neurons of the sea slug Aplysia californica, a well-established model organism for cellular neuroscience. Our objective is to investigate nearly all messenger RNA (mRNA) involved in simple feeding and defensive networks.

Genomic Bases of Neuronal Identity and Plasticity. This year we have completed our collection and initial inventory of Aplysia neuronal mRNAs from identified neurons and even from their individual processes and growth cones. In collaboration with Columbia University (J. Ju and E. Kandel), we have generated more than 230,000 molecular markers of expressed genes (ESTs) and identified thousands of unique Aplysia genes operating in the central nervous system. These include genes associated with neurodevelopment, synaptogenesis and memory. We also identified several dozen genes homologous to those associated with human diseases such as Alzheimer’s disease and causes of mental retardation (the Alzheimer’s disease related protein and the Fragile X mental retardation protein). We are analyzing the functional role of these novel and critical genes using Aplysia-specific microarrays, in situ hybridization, capillary electrophoresis, confocal and time-lapse imaging and microelectrode techniques. These technologies are integrated to elucidate the entire molecular machinery of a living neuron. The neuronal transcriptome of Aplysia has been published. For more informationa and to view the abstract, click here. Our lab has also embarked on a project, supported by NIH, to sequence the entire Aplysia genome. Click here to find out more.

Development of Innovative Bionanotechnologies for Direct Single Cell Genomic and Microchemical Analysis. We are working to reveal the complex, large-scale molecular machinery of individual neurons by monitoring, at real physiological time, the activity of thousands of genes
and hundreds of metabolites in the cell. Our goal is to identify a set of genes that determine neuronal identity and control long-term nervous system modifications such as injury, learning and memory. Although we have succeeded with single neuron gene expression profiling using custom
made microarrays, real time measurements and large scale metabolite proofing is a desired but not yet achieved goal. As the first step in this direction, we are developing a new generation of intracellular sensors called molecular beacons (in collaboration with J. Ju, N. Turro and W. Tan), for direct imaging of native mRNAs in living neurons and synapses in real physiological time. These new probes allow us to monitor mRNA trafficking and relocation in both cell culture and intact ganglia as neurons learn and remember. We also continue to use microanalytical approaches to detect and measure microscopic quantities of important chemicals in neurons. The primarily technique, capillary electrophoresis, is so exquisitely sensitive that less than 0.01 of the volume of a cell is all that is required for a detailed chemical analysis of its contents. Developing (in collaboration with Jonathan Sweedler) and extending these microchemical technologies to other cell types and multiple metabolites (the neuronal "metabolome") as well as their integration to real-time electrophysiological analysis (by on-line sampling of cytoplasm) are our goals for the coming years.

Comparative Neurobiology Projects:
The third project focuses on physiological mechanisms and evolution of gaseous signaling in the nervous system. Nitric oxide (NO) is a signaling molecule involved in a myriad of biological functions. Nerve cells that produce NO, the most mysterious and least analyzed
population of cells in the brain, are now our primary research target. Recently, we identified and mapped these neurons, successfully isolating genes involved in NO synthesis in molluscs, lower chordates and cnidarians. We are now examining how NO acts in neuronal networks. Gaseous
transmission has been reconstructed in cell culture where we have started to create a molecular portrait of a nitrergic neuron and identify targets of NO action. The emerging picture is that NO can be highly compartmentalized in a neuron, yet it might affect numerous signaling pathways by direct
and indirect interaction with other cellular messengers. Finally, we discovered that in certain neurons NO can be generated by a non-enzymatic mechanism via nitrite-ascorbate interactions, and we continue to characterize this non-traditional mechanism of NO synthesis in cells.

The goal of our fourth project is to use comparative strategies to determine what genes define neurons, focusing upon basal animal groups. First, we make and sequence cDNA libraries from Trichoplax, having the simplest organization of any known animal, with only four distinguishable cell types, but with prominent social behavior. Second, this year we started to sequence Xenoturbella, an enigmatic marine organism that is considered as the representative of the most basal deuterostome group with a nervous system in the form of a nerve net. Finally, we use larval nervous systems from molluscs and echinoderms as important outgroups in this genomic screening. Such an approach will provide a foundation for phylogenetic analysis of gene loss and gain in both basal and more derived nervous systems and identify a subset of neuron-specific genes. These projects are performed in collaboration with Profs. P. Anderson and B. Battelle. The goals of the research are twofold: to establish novel genomic models and to understand the molecular basis and evolution of major signaling pathways focusing on identification of evolution's most conserved mechanisms of neuronal identity and plasticity as well as trends leading to innovations in neuronal functions.

Personnel

Leonid L. Moroz, Ph.D. – Professor of Neuroscience
James C. Netherton III, Chemist – chemistry, lab management
Fahong Yu, Bioinformatics and Software Specialist – bioinformatics, database
Do Sung Sohn, Graduate Student – neuroscience, molecular biology
Jinnie Sloan – Graduate Student
Yelena Bobkova – Biological Scientist
Matt Citarella – Laboratory Technician

Selected Publications

Moroz, L.L., Kohn, A.B. (2007) On the comparative biology of NO synthetic pathways: Parallel evolution of NO mediated signaling. In Nitric Oxide, Advances in Experimental Biology, Volume 1. (Eds. Trimmer, B., Tota, B. & Wang, T.) Elsevier BV, Amsterdam, 1-45.

Antonov I, Ha T, Antonova I, Moroz L.L., & Hawkins RD. (2007) Role of nitric oxide in classical conditioning of siphon withdrawal in Aplysia. J. of Neuroscience: 27(41):10993-11002.

Hatcher, N.G., Zhang, X., Stuart, J.M., Moroz, L.L., Sweedler, J.V. and Gillette, R. (2007) 5-HT and 5-HT-SO(4), but not tryptophan or 5-HIAA levels in single feeding neurons track animal hunger state. J Neurochem. 2007 Nov 23; [Epub ahead of print]

Moroz, L.L., Edwards, J. R.,  Puthanveettil, S.V., Kohn, A.B. et al. (2006) Neuronal transcriptome in Aplysia: Neuronal Compartments and Circuitry. Cell: 127(7): 1453-1467.

Bourlat, S.J., Juliusdottir, T., Lowe, C.J., Freeman, R., Aronowicz, J., Kirschner, M., Lander, E.S., Thorndyke, M., Nakano, H., Kohn, A.B., Heyland, A., Moroz, L.L., Copley, R.R., Telford, M.J. (2006). Deuterostome Phylogeny Reveals Monophyletic Chordates and the New Phylum Xenoturbellida. Nature, 444, 85-88.

Lovell, P. and Moroz, L.L. (2006). The largest growth cones in the animal kingdom and dynamics of neuronal growth in cell culture of Aplysia. April 15 Integrative and Comparative Biology, 46, 847-870.

Heyland, A. Reitzel, A.M.., Price, D.A., Moroz, L.L. (2006). Endogenous thyroid hormone synthesis in facultative planktotrophic larvae of the sand dollar Clypeaster rosaceus: Implications for the evolutionary loss of larval feeding. Evolution & Development, 8(6): 568-579.

Heyland, A., Moroz, L.L. (2006). Signaling mechanisms underlying metamorphic transitions in animals.  Integrative and Comparative Biology. p. 1-17; doi:10.1093/icb/icl023, in press

Thomas Flatt, Leonid L. Moroz, Marc Tatar, and Andreas Heyland. (2006). A potential role for thyroid hormones in Drosophila melanogaster development and immunity. J. Integrative and Comparative Biology, 1-18; doi:10.1093/icb/icl034, in press

Heyland, A. Reitzel, A.M.., Price, D.A., Moroz, L.L. (2006). Endogenous thyroid hormone synthesis in facultative planktotrophic larvae of the sand dollar Clypeaster rosaceus: Implications for the evolutionary loss of larval feeding. Evolution & Development, 8(6): 568-579.

Ha, T.J., Kohn, A.B., Bobkova, Y.V., Moroz, L.L. (2006) Molecular characterization of NMDA-like receptors in Aplysia and Lymnaea: relevance to memory mechanisms. Biological Bulletin 210(3): 255-270.

Xu, C., Xu, L., Yu, F., Tan, W., Moroz, L.L. and Li J. (2006) Nonparametric estimation of the number of unique sequences in biological samples. IEEE Transactions on Signal Processing. 54 (10), 3759-3767.

Heyland, .A, Price, D.A., Bodnarova-Buganova, M. and Moroz, L.L. (2006) Thyroid hormone metabolism and peroxidase function in two non-chordate animals. J Exp Zoolog B Mol Dev Evol. (Epub ahead of Print PMID: 16739141.

Jezzini, S.H., Reagin, S., Kohn, A.B. and Moroz, L.L. (2006) Molecular characterization and expression of a two-pore domain potassium channel in the CNS of Aplysia californica. Brain Res. 1094(1): 47-56.

Moroz, L.L. (2006) Localization of putative nitrergic neurons in peripheral chemosensory areas and the central nervous system of Aplysia californica. J Comp Neurol 495(1):10-20.

Knudsen, B., Kohn, A.B., Nahir, B., McFadden, C.S. and Moroz, L.L. (2006) Complete DNA sequence of the mitochondrial genome of the sea-slug, Aplysia californica: conservation of the gene order in Euthyneura. Mol Phylogenet Evol 38(2):459-469.

Hatcher, N.G., Sudlow, L.C., Moroz, L.L. and Gillette, R. (2006) Nitric oxide potentiates cAMP-gated cation current in feeding neurons of Pleurobranchaea californica independent of cAMP and cGMP signaling pathways. J Neurophysiol 95(5):3219-3227.

Kohn, A.B., Lea, J.M., Moroz, L.L. and Greenberg, R.M. (2006) Schistosoma mansoni: Use of a fluorescent indicator to detect nitric oxide and related species in living parasites. Exp Parasitol 113(2):130-133.

Lovell, P., Jezzini, S.H. and Moroz, L.L. (2006) Electroporation of neurons and growth cones in Aplysia californica. J Neurosci Methods 151(2):114-120.

Drake, T.J., Jezzini, S., Lovell, P., Moroz, L.L. and Tan, W. (2005) Single cell glutamate analysis in Aplysia sensory neurons. J Neurosci Methods, 144 (1 ): 73-77.

Bodnárová, M., Martásek, P. and Moroz, L.L. (2005) Calcium/calmodulin-dependent nitric oxide synthase activity in the CNS of Aplysia californica: Biochemical characterization and link to cGMP pathways. J. Inorg. Biochemistry, Apr; 99 (4):922-8.

Moroz, L.L., Dahlgren, R.L., Boudko, D., Sweedler, J.V. and Lovell, P. (2005) Direct single cell determination of nitric oxide synthase related metabolites in identified nitrergic neurons. J. Inorg. Biochemistry. 99 (4): 929-39.

Tan, L., Li, Y., Moroz, L., Drake, T., Munteanu, A., Yang, C., Martinez, K. and Tan, W. (2005) Molecular beacons for bioanalytical applications., The Analyst 130 (7): 1002-1005.

Jezzini, S.H., Bodnarova, M. and Moroz, L.L. (2005) Two-color in-situ hybridization in the CNS of Aplysia californica. J. Neurosci. Methods. 149 (1): 15-25.

Heyland, A. and Moroz, L.L. (2005) Cross-kingdom hormonal signaling: an insight from thyroid hormone functions in marine larvae. J. Exp. Biol. 208 (Pt 23): 4355-61.

Gruenhagen, J.A., Lovell P., Moroz, L.L. and Yeung, E.S. (2004) Monitoring real-time release of ATP from the molluscan central nervous system. J. Neurosci. Methods 139(2):145-152.

Ostrovskaya, O., Moroz L. and Krishtal O. (2004) Modulatory action of RFamide-related peptides on acid-sensing ionic channels is pH dependent: the role of arginine. J. Neurochem. 91(1): 252-255.

Yudin, Y.K., Tamarova, Z.A., Ostrovskaya, O.I., Moroz, L.L. and Krishtal, O.A. (2004) RFa-related peptides are algogenic: evidence in vitro and in vivo. Eur. J. Neurosci. 20(5):1419-1423.

Moroz, L.L., Meech, R.W., Sweedler, J.V. and Mackie, G.O. (2004) Nitric oxide regulates swimming in the jellyfish Aglantha digitale. J. Comparative Neurology: 471(1): 26-36.

Walters, E.T., Bodnárová, M., Billy, A.J., Dulin, M.F., Diaz-Rios, M., Muller M. and Moroz, L.L. (2004) Somatotopic organization and functional properties of mechanosensory neurons expressing sensorin-A mRNA in Aplysia californica. J. Comparative Neurology: 471(2): 219-240.

Zhulidov, P. A., Bogdanova, E. A., Altshuler, I.M., Vagner, L.L., Khaspekov, G.L., Kozhemyako, V.B., Matz, M.V., Meleshkevitch, E., Moroz, L.L., Lukyanov, S.A. and Shagin, D.A. (2004) Simple full-length cDNA normalization using kamchatka crab duplex specific nuclease. Nuc. Acid Res. 32 (3): 1-8.

Jezzini, S. and Moroz L.L. (2004) Identification and distribution two-pore domain potassium channels from the CNS of Aplysia californica. Brain Res. Molecular Brain Res. 127(1-2): 27-38.

Boudko, D.Y., Cooper, B.Y., Harvey, W.R. and Moroz, L.L. (2002) High-resolution microanalysis of nitrite and nitrate in neuronal tissues by capillary electrophoresis with conductivity detection. J. Chromatogr. B. 774: 97-104.

Kim, W.S., Dahlgren, R.L., Moroz, L.L., Sweedler, J.V. (2002) Ascorbic acid assays of individual neurons and neuronal tissues using capillary electrophoresis with laser-induced fluorescence detection. Anal. Chem. 74: 5614-5620.

Zhang X., Kim W.S., Hatcher N., Potgieter K., Moroz L.L., Gillette R., Sweedler J.V. (2002) Interfering with nitric oxide measurements: 4,5-diaminofluorescein reacts with dehydroascorbic acid and ascorbic acid. J Biol Chem. 277(50): 48472-48478.

Moroz, L.L. (2001) Gaseous transmission across time and species. Amer. Zool.41: 304-320.

Vilim, F. S., V. Alexeeva, Moroz, L.L. et al. (2001). "Cloning, expression and processing of the CP2 neuropeptide precursor of Aplysia." Peptides 22(12): 2027-38.

Boudko D.Y., Moroz L.L., Harvey W.R., Linser P.J. (2001a) Alkalinization by chloride/bicarbonate pathway in larval mosquito midgut. Proc Natl Acad Sci U S A 98:15354-15359.

Boudko D.Y., Moroz L.L., Linser P.J., Trimarchi J.R., Smith P.J., Harvey WR (2001b) In situ analysis of pH gradients in mosquito larvae using non-invasive, self-referencing, pH-sensitive microelectrodes. J Exp Biol 204:691-699.

Kohn A.B., Moroz L.L., Lea J.M., Greenberg R.M. (2001) Distribution of nitric oxide synthase immunoreactivity in the nervous system and peripheral tissues of Schistosoma mansoni. Parasitology 122 Pt 1:87-92.

Gillette, R., Huang, R., Hatcher, N., Moroz, L.L. (2000). Cost-benefit analysis potential in feeding behavior of a predatory snail by integration of hunger, taste and pain. Proc Natl Acad Sci USA: 97, 3585-3590.

Moroz, L.L., Norekian, T.P., Pirtle, T.J., Robertson, K.J., Satterlie, R.A. (2000). Distribution of NADPH-diaphorase reactivity and effects of NO-donors on feeding and locomotory circuitry in the pteropod mollusc, Clione limacina. J. Comp. Neurol., 427, 274-284

Moroz, L.L. (2000). On the origin and early evolution of neuronal NO signaling: A comparative analysis. In: Nitric oxide and free radicals in peripheral neurotransmission. (Kalsner S, ed). New York: Springer-Verlag: 1-34.

Moroz, L. L. (2000) Giant identified NO-releasing neurons and comparative histochemistry of putative nitrergic systems in gastropod molluscs. Microscopy Research and Technique 49: 557-569.

Moroz L.L., Gillette R., Sweedler J.V. (1999) Single-cell analyses of nitrergic neurons in simpler nervous systems. J Exp Biol 202:333-341.

Hurst W.J., Moroz, L.L., Gillette, M.U. and Gillette, R. (1999). Nitric oxide synthase immunolabeling in the molluscan CNS and peripheral tissues. Biochem. Biophys. Res. Com. 262, 545-548.

Moroz, L.L., Norby, S.W., Cruz, L., Sweedler, J.V., Gillette, R., Clarkson, R.B. (1998). Non-enzymatic production of nitric oxide (NO) from NO synthase inhibitors. Biochem. Biophys. Res. Com., 253, 571-576.

Fuller, R., Moroz, L.L., Gillette, R., and Sweedler, J.V. (1998). Serotonin and related molecules in identified neurons: Direct analysis of intracellular concentrations by capillary electrophoresis with fluorescence spectroscopy. Neuron, 20, 173-181.

Floyd, P., Moroz, L.L., Gillette, R., and Sweedler, J.V. (1998). Capillary electrophoresis analysis of nitric oxide synthase related metabolites in single identified neurons. Anal. Chem., 70, 2243-2247.

Sudlow, L., J. Jing, Moroz, L.L., and Gillette, R. (1998). Serotonin-containing neurons in the CNS of the opisthobranch molluscs,Pleurobranchaea californica and Tritonia diomedea.J.Comp. Neurol.,395, 466-480.

Moroz, L.L., Sudlow, L.C., Jing, J., Gillette, R. (1997). Serotonin-immuno reactivity in peripheral tissues of the opisthobranch molluscs Pleurobranchaea californica and Tritonia diomedea. J. Comp. Neurol. 382, 176-188.

Cruz, L., Moroz, L.L., Gillette, R., Sweedler, J.V. (1997). Nitrite and nitrate levels in individual molluscan neurons: Single cell capillary electrophoresis analysis. J. Neurochem., 69, 110-115.

Moroz, L.L. and Gillette, R. (1996). NADPH-diaphorase localization in the CNS and peripheral tissues of the predatory sea-slug, Pleurobranchaea californica. J. Comp. Neurol., 367, 607-622.

Moroz, L.L., Chen, D., Gillette. M.U. and R. Gillette (1996). Nitric oxide synthase activity in the molluscan CNS. J. Neurochem. 66, N2, 873-876.

Leake, L.D. and Moroz L.L. (1996). Putative nitric oxide synthase (NOS)-containing cells in the central ner-vous system of the leech, Hirudo medicinalis: NADPH-diaphorase histochemistry. Brain Res.723,115-124.

Garden, R.W., Moroz, L.L., Moroz, T.P., Shippy, S.A., Sweedler, J.V. (1996). Excess salt removal with matrix rinsing: Direct peptide profiling of neurons from marine invertebrates using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. J. Mass Spectrometry 31,1126-1130.

Moroz L.L, Gillette R (1996) From Polyplacophora to Cephalopoda: comparative analysis of nitric oxide signaling in Mollusca. In: Neurobiology of invertebrates: simple and complex regulatory systems. (Salanki J, S-Rozsa K and Elekes K, eds), pp. 169-182. Budapest: Akademia Kiado.

Kurenny, D.E., Moroz, LL., Turner, R.W., Sharkey, K.A. and Barnes, S. (1994). Modulation of ionic channels in rod photoreceptors by nitric oxide. Neuron, 13, 315-324.

Moroz L.L, Radbourne S, Winlow W (1996) The use of NO-sensitive microelectrodes for direct detection of nitric oxide (NO) production in molluscs. In: Neurobiology of invertebrates: simple and complex regulatory systems. (Salanki J, S-Rozsa K and Elekes K, eds), pp. 155-167. Budapest: Akademia Kiado.

Turner, R.W. and Moroz, L.L. (1995). Localization of nicotinamide adenine dinucleotide phosphate-diaphorase activity in electrosensory and electromotor systems of a gymnotiform teleost, Apteronotus leptorhynchus. J. Comp. Neurol., 356, 261-274.

Park, J.-H., Budko, D.Yu, Moroz, L.L. and Winlow, W. (1995) Optical monitoring of movements in small animals and in semi-intact preparations. J. Neurosci. Meth. 56, 181-186.

Kurenni, D.E., Thurlow, G.A., Turner, R.W., Moroz, L.L., Sharkey, K.A. and Barnes, S. (1995). Nitric oxide synthase in tiger salamander retina. J. Comp. Neurol., 361, 525-536.