It seems that model 5 amplifier is designed specifically for intracellular recording. Typically, differences between intra- and extracellular microelectrode amplifiers include (i) gain (amplification) and (ii) DC versus AC coupling. Presumably, gain of intracellular amplifier would not be sufficient, DC offset at high amplification can result in additional complication. To some extent, this problem could be solved by adding additional commercially available amplifier with AC coupling (or a simple, basically, one chip hand-made circuit).