FIGURE 3.

Schematic illustration of an implanted part of the perforated polyimide platform and the orientation of 40 μm thick horizontal cryostat slices along with paraformaldehyde fixed cortical tissue around it. (A) A number of cortical slices were prepared from the platform tip (T), perforated (P) and solid (S) parts. Consecutive confocal microscope optical sections were grabbed from the immunolabeled slices at intervals of 1 μm to prepare maximal projection images of the sectioned platform and the tissue surrounding it. (B) The integrated immuno-fluorescent intensity within the electrode (central yellow rectangle) and within nine, 25 μm wide centripetal shells around it were measured and processed to establish the normalized fluorescent intensity level (NFI) of a given cell type at a given distance around the electrode. The image in (B) depicts neuron cell bodies and neurites labeled by NeuN and NF, respectively.