Electric impedance sensing during the inhibition of cell-cell adhesion

Electric cell impedance sensing (ECIS) was used to monitor the change of in vitro neuron-neuron adhesion in response to the blocking of N-Cam, N-Cadherin and L1. ECIS is a method in which cell morphology and cell mobility can be indirectly measured by changes in intercellular resistance. Antibodies and soluble extracellular domains of the cell adhesion molecules N-Cam, N-Cadherin and L1 were used as blockers of these adhesion molecules on the cell surface. In a 96 hour aggregation assay on a low adhesive substrate, the effect of mentioned blockers on the aggregation was investigated. The N-Cadherin antibody showed effective in aggregation inhibition at concentrations of 3 and 10 micrograms/ml. Up to 96 hours no aggregation occurred. A similar effect was achieved by the N-Cadherin protein, although less distinct. Blocking of N-CAM and L1 revealed no inhibition of aggregation. Results from impedance measurements correspond to those of the aggregation assays. The neuron-neuron adhesion in monolayers was inhibited by blocking of cell adhesion molecules and monitored by ECIS. Impedances of neuron covered electrodes were significantly lower in the presence of N-Cadherin antibody and protein at concentrations of 1, 3 and 10 micrograms/ml, indicating a less profound binding between adjacent neuron.The results from both the aggregation assays and the impedance measurements demonstrate the applicability of CAM blocking for the regulation of culture topography.