Neurochemistry and Cell/Developmental Biology
 

M.S., Tel-Aviv University, Israel, 1968
Ph.D., The Weizmann Institute of Science, Israel, 1973
 

Teaching Activities

General Biology I
General Biology II
General Biology I Lab
Molecular Foundations of Cell Function
Biological Principles I
Human Anatomy and Physiology I
 

Research Activities

My research aims to elucidate molecular mechanisms underlying neuronal adaptation and synaptic plasticity that can reveal the
biochemical basis of the process of learning and the formation of memory. Current investigations in our laboratory focus on two
discoveries that opened new directions in this research: (1) Our early studies have revealed that intracellular protein
phosphorylation systems in the brain serve as key mechanisms of molecular adaptation in processes whereby hormonal,
pharmacological, and behavioral inputs induce long-lasting alterations in neuronal function. Recently, we have discovered that the
powerful regulatory machinery of protein phosphorylation operates also in the extracellular environment. The enzyme ecto-protein
kinase utilizes ATP secreted by stimulated neurons to phosphorylate proteins localized at the external surface of the neuronal
plasma membrane (reported first in NATURE, 1986). These phosphorylative modifications appear to be involved in interactions
that are critical both to neuronal development and synaptic plasticity, such as cell adhesion, neurite outgrowth, synaptogenesis,
receptor specificity and a form of memory called long-term-potentiation (LTP). A specific surface phosphorylation system was
found to be a direct target for Alzheimer's anyloid peptides. The purification of surface phosphorproteins and generation of
antibodies and synthetic peptides that influence cellular functions without penetrating cells will provide a new generation of
therapeutic agents. (2) The alkyl-ether phospholipid called platelet-activating-factor (PAF) is a most potent mediator of
inflammation and allergic reactions. Our studies have discovered that PAF has significant roles in the nervous system (reported
first in SCIENCE, 1988). At physiological concentrations, PAF can induce differentiation during neuronal development, and LTP
in mature brain neurons. At pathological levels, PAF is an excitotoxin inducing neurodegeneration in an apoptotic process that
involves receptor-mediated calcium fluxes. These neuroregulatory and neuropathological actions of PAF present a new target in
drug discovery for the treatment of developmental disabilities and neurodegenerative disorders.
 
 
 

Publications
Ehrlich, Y.H.  (1996).  Extracellular protein kinases. Science 271:278-279.

Babinska, A., Ehrlich, Y.H., and Kornecki, E.  (1996).  Activation of Human Platelets by Protein Kinase C Antibody: role of ecto-protein kinase in platelet homeostasis.  American J. Physiol: Heart and Circulatory Physiology 271:H2134-H2144.

Chen, W., Wieraszko, A., Hogan, M.V., Yang, H-A, Kornecki, E. and Ehrlich, Y.H.  (1996).   Surface protein kinase is required for the maintenance of long-term potentiation. Proceedings of the National Academy of Science USA 93:8688-8693.

Hogan, M.V., Pawlowska, Z., Yang, H., Kornecki, E. and Ehrlich, Y.H.  (1995).  Ecto-protein kinase C on the surface of brain neurons: A target for Alzheimer's ß-Amyloid peptides.  J. of Neurochemistry 65:2022-2030.

Wieraszko, A., and Ehrlich, Y.H.  (1994).  The role of extracellular ATP in long term potentiation. J. Neurochem.

Wieraszko, A., Li, G., Kornecki, E., Hogan, M.V., and Ehrlich, Y.H.  (1993). Long-term potentiation in the hippocampus induced by platelet activating factor (PAF).  Neuron 10:553-557.

Pawlowska, Z., Hogan, M.V., Kornecki, E., and Ehrlich, Y.H.  (1993).  Ecto-protein kinase and surface phosphorylation in PC 12 cells: Interactions with nerve growth factor.  J. Neurochem. 60:678-686.