Is Zinc a Neuromodulator?
Alan R. Kay1* and
Katalin Tóth2
1Department of Biology, 336 BB, University of Iowa, Iowa City, IA 52242, USA.
2Centre de Recherche and Department of Psychiatry, Université Laval Robert Giffard, 2601 chemin de la Canardière, F6550, Québec, QC G1J 2G3, Canada.
Abstract:
The vesicles of certain glutamatergic terminals in the mammalian forebrain are replete with ionic zinc. It is believed that during synaptic transmission zinc is released, binds to receptors on the pre- or postsynaptic membranes, and hence acts as a neuromodulator. Although exogenous zinc modulates a wide variety of channels, whether synaptic zinc transits across the synaptic cleft and alters the response of channels has been difficult to establish. We will review the evidence for zinc as a neuromodulator and propose diagnostic criteria for establishing whether it is indeed one. Moreover, we will delineate alternative ways in which zinc might act at synapses.
*Corresponding author. E-mail, alan-kay{at}uiowa.edu
