Ih is an important contributor to the subthreshold membrane properties of various mammalian neurons, including interneurons. Here I characterize the properties of Ih in a subpopulation of hippocampal area CA3 interneurons with somata in stratum radiatum and stratum lacunosom moleculare. As shown in previous studies, Ih in these cells has sigmoidal voltage dependence of activation with kinetics characterized by two exponential components for both channel activation and deactivation. Interestingly, the activation and deactivation kinetics were most aptly described by distinct functions of voltage. These results were incorporated into a novel biophysical model of Ih that was applied in single compartment model simulations and dynamic clamp experiments. Finally, I assessed the functional consequences of Ih by examining the effects of this current on subthreshold temporal summation of mossy fiber EPSPs as well as frequency dependent neuronal responses. My results show that Ih decreases temporal summation of mossy fiber EPSPs but does not impart resonance in CA3 interneurons at potentials where Ih is active
