Related Experiment Video
Updated: Oct 13, 2026

Whole Cell Recording from an Organotypic Slice Preparation of Neocortex
Published on: June 3, 2011
Ontogeny of apical membrane ion conductances and channel expression in cortical collecting duct cells
1Physiologisches Institut, Universität München, Germany.
Abstract:
Ontogeny of apical-basolateral epithelial cell polarity was studied by a comparison of embryonic ureteric bud (UB) and mature cortical collecting duct (CCD) primary cultures. Patch-clamp techniques were applied to identify apical ion channels and to measure specific conductance (in nS/10 pF) of the apical membrane (ga) and of the whole cell (Gw). In UB, Gw (1.3 +/- 0.17; n = 32) and ga (1.4 +/- 0.15; n = 9) were not different, whereas they differed greatly in CCD (Gw: 0.79 +/- 0.07, n = 35; ga: 2.3 +/- 0.38, n = 9). In UB, 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) (100 microM) similarly reduced ga and Gw by 0.66 +/- 0.21 (n = 9) and 0.48 +/- 0.07 (n = 7), respectively, whereas DIDS had no effect in CCD. Amiloride (1 mM) did not alter UB conductance, whereas, in CCD, ga was more reduced than Gw (0.75 +/- 0.18, n = 8, vs. 0.22 +/- 0.10, n = 7). In addition to this Na(+)-selective conductance, a nonselective cation (NSC) conductance was enriched sixfold in the apical membrane of CCD, possibly due to apical 9 +/- 1-pS (n = 7) NSC channels, whereas UB apical NSC conductance was low. Apical 16 +/- 2-pS (n = 6) K+ channels were identified in CCD but not in UB. The comparison of both developmental states suggests a differentiation of the apical membrane during UB to CCD ontogeny.
Related Concept Videos
Non-gated Ion Channels
Compared to the gated ion channels, the non-gated channels, also known as leakage or passive channels, have no gating mechanism.
The Role of Ion Channels in Neuronal Computation
Sometimes a single EPSP is strong enough to induce an action potential in the postsynaptic neuron. However, multiple presynaptic inputs must often create EPSPs around the same time for the postsynaptic neuron to be sufficiently depolarized to fire an action potential.
Electrochemical Gradient and Channel Proteins: An Overview
The electrical gradient: The electrical gradient across cell membranes refers to the difference in electric charge between the inside and outside of a cell. This difference drives the movement of ions towards or away from the cells. For instance, if the inside of the cell is more negatively charged relative to the...
Renal Tubule and Collecting Duct
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...

