Electrophysiological development of embryonic hippocampal neurons from the rat grown on synthetic thin films

We have studied the electrophysiological properties of hippocampal neurons grown on surfaces of organic thin films formed on glass or silicon substrates and on microelectronic device surfaces in culture. Hippocampal neurons were dissociated from embryonic rats and plated on substrates chemically modified with laminin peptide in a chemically defined medium. The electrophysiological properties of the neurons were studied using patch-clamp amplifier technique. We observed that the neurons grown on these substrates develop resting membrane potentials more negative than -33 mV after 3 days in culture and are able to produce action potentials. More interestingly we found that the neurons when grown on the microelectronic surfaces develop similar electrophysiological characteristics as those on the glass surfaces. Passive electrical properties (Cm = 27 +/- 5 pF, Rm > or = 1 G omega) of the neurons studied by impedance spectroscopy did not change considerably during the first week in culture.