Subcellular localization of SK channels in rodent brain

SK channels, a group of small-conductance calcium-activated potassium channels (SK1, SK and SK3), are quite unexplored in mammals, both with respect to their pharmacological properties and ultra-structural localization in the central nervous system. Sequence directed antisera against all channel isoforms have been raised and characterized at the Institute for Biochemical Pharmacology, University of Innsbruck. Quite recently, we established the immunohistochemical distribution profile for SK channels in the rodent CNS. Functional studies on the implication of gene expression could have been carried out only for the SK3 channel so far. SK3 overexpression induced abnormal respiratory responses to hypoxia and compromised parturition (Science 289: 1942-1946, 2000). This proposal aims to establish the localization of SK channels at the ultra-structural level to provide a neuroanatomical basis for the understanding of SK channel function. Therefore, well characterized antibodies will be subjected to electron-microscopic detection methods established at the Institute for Basic Medical Sciences, University of Oslo. (I) The cell-type specific expression of SK channels will be investigated using confocal immunofluorescence and pre-embedding electron microscopy. (II) Post-embedding immunogold labeling techniques will be performed to study their ultra-structural localization and coupling to other ion channels (e.g. voltage-gated calcium channels).