Fiona E. Parkinson
Professor & Head - Department of Pharmacology and Therapeutics
University of Manitoba
753 McDermot Avenue, Chown Building A402, Winnipeg, MB R3E 0T6
tel: (204) 789-3589 fax: (204) 789-3932
email:  fiona.parkinson@med.umanitoba.ca

Research Focus:

Adenosine receptor signalling plays an important role in a wide range of neurological conditions, including epilepsy, stroke, Parkinson’s Disease, and has been suggested to be important in psychiatric conditions such as psychosis and depression.  Two of the world’s most popular drugs, caffeine and ethanol, owe some (ethanol) or all (caffeine) of their effects to altering adenosine receptor activity; this further underlines the importance and relevance of our studies. 

Adenosine is an important inhibitory neuromodulator in the brain.  Its concentration is controlled by purine enzymes as well as by cellular transport processes (nucleoside transporters) that carry adenosine across cell membranes.  ATP is also an important signalling molecule, in addition to its role as an energy molecule.  Both ATP receptors (termed purinergic; P2) and adenosine receptors are located on cell surfaces, so the extracellular concentrations of ATP and adenosine determine their level of activity.  Adenosine can be formed from ATP both inside and outside cells.  Understanding where adenosine comes from (e.g. which cell types, enzymes, transporters), and how it can be produced so rapidly during ischemic events, are major focuses of my research. 

Many drugs, including caffeine and ethanol, act at least in part through effects of adenosine receptor signalling.  Another focus of my research is investigating the mechanisms of action of these drugs, and others, that affect adenosine signalling. 

Using a wide range of techniques, from molecular to behaviour, my laboratory is investigating the cellular sources of neuroactive adenosine and mechanisms by which drugs or diseases enhance adenosine receptor signalling. 

Current funding for this research is from Natural Sciences and Engineering Research Council, the Heart and Stroke Foundation of Manitoba, and the Canadian Institutes of Health Research.

Recent Publications:

Zhang, D., W. Xiong, B.C. Albensi and F.E. Parkinson. 2011. Expression of human equilibrative nucleoside transporter 1 (hENT1) in mouse neurons regulates adenosine levels in physiological and hypoxic-ischemic conditions. J. Neurochem. 118:4-11.

Kost, S., C. Sun, W. Xiong, K. Graham, C.E. Cass, J.D. Young, B.C. Albensi and F.E. Parkinson. 2011. Behavioral effects of elevated expression of human equilibrative nucleoside transporter 1 in mice. Brain Behav. Res.224:44-49.

Nam, H.W., S. McIver, D.J. Hinton, M.M. Thakkar, Y. Sari, F.E. Parkinson, P. Haydon and D.S. Choi. Adenosine and glutamate signaling in neuron-glial interaction: Implication in alcoholism and sleep disorders.  Alcohol. Clin. Exp. Res., in press.

Parkinson, FE, VL Damaraju, K Graham, SYM Yao, SA Baldwin, CE Cass and JD Young. 2011. Transporters of nucleosides and their metabolites in the brain.  Curr. Top. Med. Chem. 11:948-972.

Zamzow, CR, R Bose, and FE Parkinson. 2009. NMDA-evoked adenosine and inosine release from neurons requires calcium. Can. J. Physiol. Pharmacol. 87:850-858.

Parkinson FE, W. Xiong, CR Zamzow, T Chestley, T Mizuno, ML Duckworth. 2009. Transgenic expression of human equilibrative nucleoside transporter 1 mouse neurons.  J. Neurochem. 109:562-572.

Zamzow, CR, W Xiong and FE Parkinson. 2008.  Adenosine produced by neurons is metabolized to hypoxanthine by astrocytes.  J. Neurosci. Res. 86:3447-3455.

Zamzow, CR, W Xiong and FE Parkinson. 2008.  Astrocytes affect the profile of purines released from cultured cortical neurons.  J. Neurosci. Res. 86:2641-2649.

*highlighted names are students