RT Journal Article
SR Electronic
T1 Distribution of high-conductance Ca(2+)-activated K+ channels in rat brain: targeting to axons and nerve terminals
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 955
OP 963
DO 10.1523/JNEUROSCI.16-03-00955.1996
VO 16
IS 3
A1 HG Knaus
A1 C Schwarzer
A1 RO Koch
A1 A Eberhart
A1 GJ Kaczorowski
A1 H Glossmann
A1 F Wunder
A1 O Pongs
A1 ML Garcia
A1 G Sperk
YR 1996
UL http://www.jneurosci.org/content/16/3/955.abstract
AB Tissue expression and distribution of the high-conductance Ca(2+)- activated K+ channel Slo was investigated in rat brain by immunocytochemistry, in situ hybridization, and radioligand binding using the novel high-affinity (Kd 22 pM) ligand [3H]iberiotoxin-D19C ([3H]IbTX-D19C), which is an analog of the selective maxi-K peptidyl blocker IbTX. A sequence-directed antibody directed against Slo revealed the expression of a 125 kDa polypeptide in rat brain by Western blotting and precipitated the specifically bound [3H]IbTX-D19C in solubilized brain membranes. Slo immunoreactivity was highly concentrated in terminal areas of prominent fiber tracts: the substantia nigra pars reticulata, globus pallidus, olfactory system, interpeduncular nucleus, hippocampal formation including mossy fibers and perforant path terminals, medial forebrain bundle and pyramidal tract, as well as cerebellar Purkinje cells. In situ hybridization indicated high levels of Slo mRNA in the neocortex, olfactory system, habenula, striatum, granule and pyramidal cell layer of the hippocampus, and Purkinje cells. The distribution of Slo protein was confirmed in microdissected brain areas by Western blotting and radioligand-binding studies. The latter studies also established the pharmacological profile of neuronal Slo channels. The expression pattern of Slo is consistent with its targeting into a presynaptic compartment, which implies an important role in neural transmission.