resume: Electrophysiology and biomechanics

Ahmed Lazrak Ahmed.Lazrak at
Sat Jan 18 08:41:47 EST 1997

Ahmed Lazrak
411 West Vanderbilt Drive
Oak Ridge, TN 37830


Ahmed Lazrak Ph.D.
ORNL EMF Bioeffects Research Program  
Oak Ridge National Laboratory
PO Box 2008, MS-6125
Oak Ridge, TN 37831-6125
Tel: 423-241-4358
Fax: 423-576-4407

Ahmed.Lazrak at
BnLent at
Lazraka at



A career in biological sciences.


French, English and Arabic.


* Doctorate or Ph.D. 1989.
Cell Biology & Molecular Biology
Cell Electrophysiology and Biophysics
University of Poitiers, France

* Master's Degree. 1985.
Cell Biology & Molecular Biology
University of Poitiers, France

* B.Sc. 1983.
University Med I Oujda, Morocco
General Biology & Geology

Actual position: Research Scientist

Some of my research interests:

Role of calcium ions in Cell signaling, in excitation-contraction coupling, and in cell to cell communication.

Employment History:

1. Oak Ridge National Laboratory (ORNL)and Oak Ridge Associated Universities (ORAU), Oak Ridge, Tennessee. Department: Energy, RAPID Program.
From: May 11,1995-Present
Duties: ELF and EMF Biological effects

2. University Of Rochester, Rochester, NY
Department: Physiology
From: September, 1991-April, 1995
Duties Included: Gap junction regulation by calcium, hydrogen ions, and voltage. 


Electrophysiology and Biophysics
* Patch clamp electrophysiology, Whole cell and double whole cell techniques.
* Double voltage clamp of isolated pairs of myocytes and paired oocytes.
* Imaging procedures of intracellular calcium and Hydrogen ions.
* Use computers and related hardware and scientific software for running experiments, for data acquisition and analysis: Pclamp6.03 , Axotape2 , Axoscope1.1, Origin 4, Microsoft Office, Statistica, Sigmaplot
* Primary cell culture of embryonic cells.
* Cell culture procedures.
* Floating Micro electrode in association with a force transducer for simultaneous measurement of electrical and contractile activities of isolated frog skeletal muscle fibers.
* Dissection and Micro-dissection of skeletal muscle fibers, mammalian organs, and Frog oocytes.
* Detection of myocytes and skeletal muscle fibers mechanical activity, using electromechanical sensors.
* Cell isolation techniques, enzymatic procedures, from embryonic and adults organs (heart, liver...etc.).
* Ability to construct setups, adapt and implement new techniques as needed.

Research Experience

April 1995-Present: 
Effects of electromagnetic fields on cell membrane function. Cells in culture, cell lines and primary cultures, are exposed to ELF-EMF and the effect on the cell to cell communication is studied. The Junctional coupling is measured using the double whole cell patch clamp procedure on cell pairs. The effects of ELF-EMF is studied on primary cultures of embryonic myocytes, the contraction of myocytes is monitored using an electromechanical sensor. In collaboration with Doctor Paul C. Gailey (Energy Division, ORNL) and Doctor Guy D. Griffin (Health Science Research Division, ORNL).

September 1991-April 1995:
Regulation of the gap junction function by second messengers in the Novikoff hepatoma cell line. The dual method of double-whole cell configuration (patch-clamp) and voltage-clamp is used to measure the macroscopic Junctional current and single gap Junctional channel. The intracellular imaging method is used to measure the changes in the intracellular calcium concentration in cell pairs following treatments that are known to modulate and/or to reduce the cell-to-cell coupling.

January 1990-June 1991:
An attempt to the study of the electrophysiological changes in the red blood cell membrane Electrophysiology induced by the Malaria parasite, Plasmodium Falciparum. In collaboration with Professors J. Délèze and J. Schrevel. 

Ph.D. Study of the electrical properties of the isolated pairs of myocytes from adult rat hearts, the study was performed using the double micro electrodes and double-whole cell (patch-clamp) under voltage clamp or current-clamp conditions. Supervisor: Professor J. Délèze, University of Poitiers, France.

Master's research project: Study of the excitation-contraction coupling of the isolated skeletal muscle fiber of the frog. The study was performed using simultaneously floating micro-electrode for recording the electrical activity while the contractile activity was recorded using an electromechanical transducer. Under the supervision of Professor J. Délèze, University of Poitiers, France. 

Postdoctoral Experience
* University of Rochester, NY, USA
Physiology: September, 1991-April 1995

* Oak Ridge National Laboratory (ORNL), Energy Division
and Oak Ridge Associated Universities (ORAU), USA
Health effect of Extremely low Frequency Electromagnetic Fields
April 1995- Present


1. Lazrak, A. and C. Peracchia. 1993. Gap junction sensitivity to physiological calcium regardless of pH in Novikoff hepatoma cells. Biophysical J. 65: 2002-2012.

2. Lazrak, A. and C. Peracchia, 1993 . Nanomolar calcium mediates gap junction gating by low pH in Novikoff cells. In: Gap Junctions Y. Kanno ed. Progress in Cell Research. Elsevier Science, Amsterdam, The Netherlands, 1993. 

3. Lazrak, A., A. Peres, S. Giovannardi, and C. Peracchia, 1993. Calcium participation in ATP and arachidonic acid but not in oleic acid and halothane induced gating of gap junctions in Novikoff cells. In: Gap Junctions Y. Kanno ed. Progress in Cell Research. Elsevier Science, Amsterdam, The Netherlands, 1993. 

4. Lazrak, A., A. Peres, S. Giovannardi. and C. Peracchia. 1994. Ca mediated and independent effects of arachidonic acid on gap junctions and Ca independent effects of oleic acid and halothane. Biophysical . J. 67:1052-1059

5. Haiying Li, Tai-Feng Lui, Ahmed Lazrak, Camillo Peracchia, Gary Goldberg, Paul Lampe, and Ross Jonhson, 1996. Properties and Regulation of Gap junction Hemichannels in the Plasma Membranes of Cultured cells. Journal of Cell Biology, 1996. In Press

6. Lazrak. A, G.D. Griffin and P.C. Gailey, 1996. A method for studying the effect of electrical field on contractile activity isolated myocytes. Submitted.

7. Lazrak, A., 1985. Etudes du couplage électromécanique de la fibre musculaire squelettique de grenouille isolée. Memoire de D.E.A. University of Poitiers, Poitiers, France.

9. Lazrak, A., 1989. Etudes des propriétés électriques des myocytes isolés de coeur de rat adultes. Ph.D. Thesis. University of Poitiers, Poitiers France.

10. Peracchia, C., A. Lazrak and L.L. Peracchia 1994. Molecular models of channel interaction and gating in gap junctions. In: Handbook of Membrane Channels. Molecular and Cellular Physiology . C. Peracchia, ed. Academic Press, Inc., San Diego, CA. p361-377. 

11. Délèze, J., A. Lazrak and V. S. Rakotonirina. 1985. Séparation des potentials d'action engendés s par la membrane de surface et par la membrane des tubules transverses de la fibre musculaire squelettique de grenouille. J. Physiol.(PARIS). 80:45a.

12. Délèze, J., A. Lazrak and V. S. Rakotonirina. 1985. Isolation of the tubular action potential in the frog skeletal muscle fibers. J. Physiol. (Lond.). 371:149P. 

13. Lazrak, A. and C. Peracchia. 1992. Gap junctions of Novikoff hepatoma cell pairs are Ca2+-sensitive but pH-insensitive. Molec. Biol. Cell 3, A295.

14. Lazrak, A. and C. Peracchia. 1993. Gap junction gating sensitivity to calcium and hydrogen in Novikoff hepatoma cell pairs. Proc. 1993 Int. Meeting on Gap Junctions. Hiroshima, Japan, p. 54.

15. Lazrak, A., A. Peres, S. Giovannardi and C. Peracchia. 1993. Partial uncoupling, increase in calcium and activation of K+(Ca) channels with ATP-induced stimulation of purinergic receptors linked to IP3 turnover. Proc. 1993 Int. Meeting on Gap Junctions. Hiroshima, Japan, p. 55.

16. Lazrak, A., A. Peres, S. Giovannardi and C. Peracchia. 1994. Junctional uncoupling by ATP or arachidonic acid is Cai-mediated. Biophysical . J. 65 (2, pt. 2):A149.

17. Lazrak, A., A. Peres, S. Giovannardi and C. Peracchia. 1994. ATP induces Ca2+ increase, activation of K+(Ca) channels and partial uncoupling between pairs of electrically coupled hepatoma cells. Proceedings of the Fourth European Congress of Cell Biology, Prague. 

18. Peracchia, C., A. Lazrak, A. Peres, S. Giovannardi, X.G. Wang and L.L. Peracchia. 1994. Potential role of Ca2+ and calmodulin in gap junction regulation. Workshop on Intercellular Communications. Puschino, Russia, Aug. 26-Sept.1

19. Peracchia, C., A. Lazrak, A. Peres, S. Giovannardi, X.G. Wang and L.L. Peracchia. 1994. Chemical regulation of gap junction channel permeability. XI Int. Congr. of Eye Res., New Delhi, India. 

20. Lazrak, A., Griffin, G.D. and Gailey, P. C. 1996. Alteration of cardiac myocytes by ELF-EMF. Bioelectromagnetic association annual meeting, Victoria, British Columbia, Canada, 9-14 June, 1996.

21. Gailey, P.C., H. Wachtel, A. Lazrak, G.D. Griffin, 1996. Nonlinear Dynamics and Phase Locking of Cardiac Myocytes Exposed to Weak ELF Electric Fields. BEMS, Victoria, 9-14 June, 1996. 

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