Education/Training:

Biographical Sketch:

Born and raised in Syracuse, New York, Dr. Geiger came to Winnipeg, Manitoba, Canada in 1982 to conduct post-doctoral training with Dr. Frank LaBella in the Department of Pharmacology and Therapeutics. In 1984 he accepted an appointment as Assistant Professor in the Department of Pharmacology and Therapeutics in the Faculty of Medicine at the University of Manitoba. In 1989 he was promoted to Associate Professor and in 1994 he was promoted to full Professor. In 1999, he founded and until 2003 was the Director of the Division of Neurovirology and Neurodegenerative Disorders at the St. Boniface Hospital Research Centre. In 2003, he moved back the USA where he is Chair of the Department of Pharmacology, Physiology and Therapeutics at the University of North Dakota and Principal Investigator on a $10,000,000 neuroscience center development grant.

Dr. Geiger has maintained a productive research program that has been continuously funded by local, national and international agencies. The work of Dr. Geiger has attracted widespread attention and interest and he has won a number of awards for his work including Scholarship and Scientist awards from the Canadian Institutes of Health Research. Dr. Geiger's research is focused on determining underlying mechanisms and potential therapeutic interventions for sleep disorders and against neurodegenerative diseases including Alzheimer's disease, stroke, HIV-1 dementia and traumatic brain injury. Dr. Geiger's research is supported by grants from the Canadian Institutes of Health Research, the National Heart, Lung and Blood Institute (U.S.A.) and the National Institute for Neurological Disorders and Stroke (U.S.A.) and the National Institutes on Aging (U.S.A.).

Dr. Geiger has received two University of Manitoba Presidential Outreach awards for his work related to drug use by athletes and sport enthusiasts. In May 2000, he co-founded the Centre for Substance Use in Sport and Health (SUSH), a federally funded not-for-profit organization. Dr. Geiger continues to serve on a number of local, national and international committees and advisory Boards.

Research Projects Ongoing:

Aging effects on levels/actions of the sleep regulator adenosine.
Principal Investigator: Dr. Allan I. Pack
Agency: National Institute of Aging (U.S.A.)
Type: Program Project Grant AG17628-01 03/2001 - 02/2006 $154,844 p.a. USD

The major goals of this project is to hypothesis that increased wakefulness will decrease levels of ATP, decrease levels of glycogen, increase levels of adenocine, and that TNF-alpha levels will increase with age and sleep deprivation in sleep-related brain regions.

Mechanisms for the anti-inflammatory actions of adenosine in HIV-1 dementia.
Agency: Canadian Institutes of Health Research
Type: Operating Renewal 10/01/2001 - 09/30/2004 $93,789 p.a. CDN

The proposed studies will determine the degree to which adenosine systems can decrease proinflammation and cell death induced by the HIV-1 protein Tat. Second, we will determine the cell signaling molecules important for the neuroprotective actions of adenosine. Third, we will generate a unique mouse model for HIV-1 dementia with which to test the protectant actions of adenosine. These studies are important because they will help identify mechanisms of and potential treatments for HIV-1 dementia.

Role of BNIP3 in excitotoxicity and neuronal cell death.
Agency: Canadian Institutes of Health Research
Type: Operating: 04/1/2001-03/31/05 $97,440 p.a. CDN

The main objectives of this study are; to determine the extent to which BNIP3 induces neuronal cell death; to determine the effects of BNIP3 expression on mitochondrial function; to determine the extent to which BNIP3-mediated neuronal cell death has morphological and biochemical features characteristic of apoptosis or necrosis; to determine the extent to which endoG is involved in neuronal cell death and in BNIP3 expression-induced neuronal cell death; and to detmine the involvement of BNIP3 in 'in vitro' models of neurodegenerative disorders.

Autism and AMPS lyase mutations: Cell and mouse models
$43,750 p.a. USD (02/04-02/07)
National Institutes of Health (02/03-02/07)

We propose a series of studies to clarify the biochemical and physiological consequences of ADSL deficiency both in cells in culture and in mouse models of human ADSL deficiency. For our portion of this grant we will analyze mice carrying the various wild-type and mutant human ADSL alleles individually for biochemical measures of purine metabolism and compare these results with behavioral phenotypes.

Publications (2000 - present):

1. Shepel PN, Ramonet D, Stevens P, Geiger JD. Purine level regulation
   during energy depletion associated with graded excitatory stimulation in brain.
   Neurol Res. (2005) Mar;27(2):139-48.
2. Goel, D., J.D. Geiger, D. Kreillaars, J. Shan, (CV Technologies) and G. Pierce. “Doping control urinalysis of a ginseng extract, cold-Fx, in athletes”. International Journal of Sport Nutrition and Exercise Metabolism 14 (2004) 473-480.
3. Fotheringham, J.A., M.B. Mayne, J.A. Grant, and J.D. Geiger. “Activation of adenosine receptors inhibits tumor necrosis factor-a release by decreasing TNF-a mRNA stability and p38 activity”. European Journal of Pharmacology 497 (2004) 87-95.
4. Fotheringham, J., M. Mayne, C. Holden, A. Nath, and J.D. Geiger. “Adenosine receptors control HIV-1 Tat-induced inflammatory responses through protein phosphatase”. Virology 327 (2004) 186-195.
5. Holden, C.P., A. Nath and J.D. Geiger. Diadenosine Pentaphosphate Increases Levels of Intracellular Calcium in Astrocytes by a Mechanism Involving Release from Caffeine/Ryanodine- and IP₃ Sensitive Stores. J. Neurosci. Res. 2000, 59; 276-282.
6. Mattson, M.P, F.M. LaFaerla, S.L. Chan, M.A. Lessring, P.N. Shepel, and J.D. Geiger. Calcium Signalling in the ER: Its Role in Neuronal Plasticity and Neurodegenerative Disorders. Trends in Neurological Sciences 2000, 23; 222-229
7. Nath, A., N. Haughey, M. Jones, C. Anderson, J.E. Bell and J.D. Geiger. Synergistic Increases in Neurotoxicity by the HIV-1 Proteins Tat and gp120 - Neuroprotection by Memantine. Ann. Neurol. 2000, 47; 186-194.
8. Sinclair, C.J.D., P.N. Shepel, J.D. Geiger and F.E. Parkinson. Stimulation of Nucleoside Efflux and Inhibition of Adenosine Kinase by A₁ Adenosine Receptor Activation. Biochem. Pharmacol. 2000, 59; 477-483.
9. Sinclair, C.J.D. and J.D. Geiger. Caffeine Use in Sport: A Pharmacological Review. J. Sports Med. Phys. Fitness 2000, 40; 71-79.
10. Mayne, M.B., C.P. Holden, A. Nath and J.D. Geiger. Release of Calcium from IP_3, Receptor-Regulated Stores by HIV-1 Tat Regulates TNF-a Production in Human Macrophages. J. Immunol. 2000, 164; 6538-6542.
11. S.L. Chan, M.B. Mayne, C.P. Holden, J.D. Geiger, and M.P. Mattson. Presenilin-1 Mutations Increase Levels of Ryanodine Receptors and Calcium Release in PC12 Cells and Cortical Neurons. J. Biol. Chem. 2000, 275; 18195-18200.
12. Parkinson, F.E., Y.W. Zhang, P.N. Shepel, S.C. Greenway, J. Peeling, J.D. Geiger. Effects of Nitrobenzylthioinosine on Neuronal Injury, Adenosine Levels and Adenosine Receptor Activity in Rat Forebrain Ischemia. J. Neurochem. 2000, 75; 795-802.
13. Mackiewicz, M., E.V. Nikonova, C.C. Bell, R.J. Galante, L. Zhang, J.D. Geiger and A.I. Pack. Activity of Adenosine Deaminase in the Sleep Regulatory Areas of the Rat CNS. Brain Research 2000, 80; 252-255.
14. Mackiewicz, M., J.D. Geiger, A.I. Pack. Simultaneous Assessment of Ecto- and Cytosolic-5'-Nucleotidase Activities in Brain Micropunches. J. Neurosci. Methods. 2000, 104; 9-18
15. Sullivan, P.G/J.D. Geiger, M.P. Mattson, S.W. Scheff. Dietary Supplement Creatine Protects Against Traumatic Brain Injury. Ann. Neurol. 2000, 48; 723-729.
16. Mayne, M., H.J. Yan, J. Fotheringham, C. Power, M.R. Del Bigio, J. Peeling and J.D. Geiger. Adenosine A2A Receptor Activation Reduces Pro-Inflammatory Events and Decreases Cell Death Following Intracerebral Hemorrhage. Ann. Neurol. 2001, 49; 727-735.
17. Glazner, G.W., S. Camoandola, J.D. Geiger and M.P. Mattson. Endoplasmic Reticulum D-myo-Inositol1,4,5-Trisphosphate Sensitive Stores Regulate Nuclear Factor-KappaB Binding Activity in a Calcium Independent Manner. J. Biol. Chem. 2001, 276; 22461-22467.
18. Haughey N.J., A. Nath, M.P. Mattson, J.T. Slevin and J.D. Geiger. HIV-1 Tat Potentiates Glutamate Excitotoxicity and Facilitates Calcium Influx by Phosphorylation of NMDA Receptors. J. Neurochem. 2001, 78; 457-467.
19. Othman, T., C.J.D. Sinclair, N. Haughey, J.D. Geiger and F.E. Parkinson. Ethanol alters glutamate but not adenosine uptake in rat astrocytes: Evidence for protein kinase C involvement. Neurochem. Res. 2002, 27(3); 289-296.
20. Kong, J., C.P. Holden , P.N. Shepel, B.F. Singer, M. Mackiewicz , A.I. Pack and J.D. Geiger. Brain glycogen decreases with increased periods of wakefulness - implications for homeostatic drive to sleep. J. Neuroscience. J. Neurosci. 2002, 22(13); 5581-5587.
21. Bouchard, R., A.R. Weber and J. D. Geiger. Informed Decision Making on Sympathomimetic Use in Sport and Health. Clinical Journal of Sports Medicine. 2002, 12(4); 209-224.
22. Parkinson, F., C. Sinclair, T. Othman, N. Haughey, J.D. Geiger. Differences between rat primary cortical neurons and astrocytes in purine release evoked by ischemic conditions. Neuropharmacol. 2002, 43(5); 836-846.
23. Zhang, Y.W., P.N. Shepel, J. Peeling, J.D. Geiger and F. Parkinson. Effects of Nitrobenzylthioinosine of Adenosine Levels and Neuronal Injury in Rat Forebrain Ischemia. Neurosci. Res. Commun. 2002, 30(2); 83-89.
24. Geiger, J.D. Adverse Events Associated with Supplements Containing Ephedra Alkaloids. Clinical Journal Sport Medicine. 2002, 12(4); 263.
25. Turchan, J., C.B. Pocernich, C.Gairola, A. Chauhan, B. Schifitto, D.A. Butterfield, S. Buch, O. Narayan, A. Sinai, J.D. Geiger, J.R. Berger, H. Elford, and A. Nath. Oxidative Stress in HIV Demented Patients and Protection Ex-vivo with Novel Antioxidants. Neurology 2003, 60(2); 307-314.
26. Dakshinamurti, D., S.K. Sharma and J. D. Geiger . Neuroprotective actions of pyridoxine. Biochim. Biophys. Acta. 2003, 1647 (1-2); 225-229.
27. M. Mackiewicz, E.V. Nikonova, J.E. Zimmerman, R.J. Galante, L. Zhang, J.D. Geiger and A.I. Pack. Enzymes of Adenosine Metabolism in Rat Brain: Diurnal Rhythm and Effect of Sleep Deprivation. J. Neurochem. 2003, 85(2); 348-357.
28. Shepel, N., C.P. Holden, J.D. Geiger. Ryanodine receptor modulation by diadenosine polyphosphates in synaptosomal and microsomal preparations of rat brain. Eur. J. Pharmacol. 2003, 467(1-3); 67-71.
29. Bouchard, R., R. Pattarini and J.D. Geiger. Presence and Functional Significance of Presynaptic Ryanodine Receptors. Prog. in Neurobiol. 2003, 69(6); 391-418.
30. Song, L., A. Nath, J.D. Geiger, A. Moore, and S. Hochman. Human Immunodeficiency Virus Type 1 Tat Protein Directly Activates Neuronal N-Methyl-D-Aspartate Receptors at an Allosteric Zinc-Sensitive Site. J. Neurovirol. 2003, 9(3); 399-403.