TY - JOUR T1 - Rapid Loss of Dendritic HCN Channel Expression in Hippocampal Pyramidal Neurons following Status Epilepticus JF - The Journal of Neuroscience JO - J. Neurosci. SP - 14291 LP - 14295 DO - 10.1523/JNEUROSCI.1148-11.2011 VL - 31 IS - 40 AU - Sangwook Jung AU - Lindsay N. Warner AU - Julika Pitsch AU - Albert J. Becker AU - Nicholas P. Poolos Y1 - 2011/10/05 UR - http://www.jneurosci.org/content/31/40/14291.abstract N2 - Epilepsy is associated with loss of expression and function of hyperpolarization-activated, cyclic nucleotide-gated (HCN) ion channels. Previously, we showed that loss of HCN channel-mediated current (Ih) occurred in the dendrites of CA1 hippocampal pyramidal neurons after pilocarpine-induced status epilepticus (SE), accompanied by loss of HCN1 channel protein expression. However, the precise onset and mechanistic basis of HCN1 channel loss post-SE was unclear, particularly whether it preceded the onset of spontaneous recurrent seizures and could contribute to epileptogenesis or development of the epileptic state. Here, we found that loss of Ih and HCN1 channel expression began within an hour after SE and involved sequential processes of dendritic HCN1 channel internalization, delayed loss of protein expression, and later downregulation of mRNA expression. We also found that an in vitro SE model reproduced the rapid loss of dendritic Ih, demonstrating that this phenomenon was not specific to in vivo SE. Together, these results show that HCN1 channelopathy begins rapidly and persists after SE, involves both transcriptional and nontranscriptional mechanisms, and may be an early contributor to epileptogenesis. ER -