During wakefulness, pyramidal neurons in the intact brain are bombarded by synaptic
input that causes tonic depolarization, increased membrane conductance (i.e. shunting), and
noisy fluctuations in membrane potential; by comparison, pyramidal neurons in acute slices
typically experience little background input.
Such differences in operating conditions can compromise extrapolation of in vitro data to explain
neuronal operation in vivo.
in slice experiments, we show that
CA1 hippocampal pyramidal cells switch from integrators to resonators, i.e. from class 1 to class
The switch is explained by increased outward current contributed by the M-type
potassium current IM
Thus, even so-called “intrinsic” properties may differ qualitatively between in vitro and in vivo conditions.
Prescott SA, Ratte S, De Koninck Y, Sejnowski TJ (2008) Pyramidal neurons switch from integrators in vitro to resonators under in vivo-like conditions. J Neurophysiol [PubMed]