Electrical Impedance Spectroscopy Impedimetric measurements were performed as former de- scribed [16]. Briefly, five days old spheroids were transferred to a self-developed microcavity array (MCA) with pyramidal cavities (edge length 200 mm) comprising of one electrode on each of the four cavity walls. The MCA was equilibrated with phosphate buffered saline (Invitrogen) and positioned in a self-developed, automated measurement system based on the high precision impedance analyzer Agilent 4294A (Agilent Technologies). Impedance spectra were recorded in a frequency interval ranging from 5 kHz to 5 MHz applying an alternating voltage of 100 mV. The self-developed software IMAT v1.8g (Impedance Measure- ment and Automation Tool) and IDAT v.3.6 (Impedance Data Analyzing Tool) were used for instrument controlling, data recording and processing. Cellular contribution to the impedance magnitude was extracted by automated calculation of the relative impedance (|Z|with spheroid2|Z|without spheroid)/|Z|without spheroid 6 100%). For every measurement on a spheroid, six spectra were automatically acquired (each electrode measured against each other) and averaged by the software resulting in reproducible and positioning independent cell signal. Furthermore, the maximum contribution (peak) was determined by the IDAT v3.6 software. For statistical analysis the relative impedance maxima were normalized to the experimental start (0 h). Statistical Analysis Statistical analysis was done using Prism 5 (GraphPad Software). All values are presented as means 6 standard error of mean (s.e.m.) unless described differently. For all presented graphs, complete values (means and s.e.m. or s.d.) are listed in tables in the References 1. Rodgers AB (2008) ALZHEIMER’S DISEASE Unraveling the Mystery. In: Aging NIoHNIo, editor. Silver Spring. 79. 2. 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