Developmental mapping of small-conductance calcium-activated potassium channel expression in the rat nervous system.
Bottom Line: The three SK channel subunits display different developmental expression gradients in distinct CNS regions, with time points of expression and up- or downregulation that can be associated with a range of diverse developmental events.Their early expression in embryonic development suggests an involvement of SK channels in the regulation of developmental processes.Additionally, this study shows how the postnatal ontogenetic patterns lead to the adult expression map for each SK channel subunit and how their coexpression in the same regions or neurons varies throughout development.
Affiliation: Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, 37075, Göttingen, Germany.Show MeSH
Mentions: The results of the Northern analysis raised the question of whether the developmental changes in the SK expression levels reflect changes in their distribution patterns before birth. To address this question, we performed a detailed in situ hybridization analysis and mapped the distributions of SK1, SK2, and SK3 mRNAs in the rat embryonic nervous system. An overview of the prenatal distribution of the SK channel subunits was obtained by examination of X-ray film images (Figs. 2, 3), and, for cellular resolution, emulsion-coated sections were analyzed (Figs. 4, 8, 9, 11, 3, Tables3). Overview pictures of whole embryos (E11–E17; Fig. 2) and embryonic heads (E19–E21; Fig. 3) were obtained after hybridization with radioactively labeled oligonucleotides specific for each of the three SK channel subunits. Criteria for strong vs. weak labeling of brain structures were the number of silver grains accumulated above cell somata relative to the strongest hybridization signal for each given oligonucleotide (see also Fig. 3J–L).
Affiliation: Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, 37075, Göttingen, Germany.