Functional properties of granule cells with hilar basal dendrites in the epileptic dentate gyrus

• DOI: 10.1111/epi.13605
• Publication Date: 2016-11-26T06:12:40Z
• Authors: Tony Kelly; Heinz Beck
• Keywords: Granule (geology); Granule cell

Summary Objective The maturation of adult‐born granule cells and their functional integration into the network is thought to play a key role in proper functioning dentate gyrus. In temporal lobe epilepsy, gyrus develop abnormally possess hilar basal dendrite (HBD). Although morphological studies have shown that these HBDs synapses, little known about properties or intrinsic aberrant dendrites. Methods We performed patch‐clamp recordings within cell layer “normotopic” from sham‐control status epilepticus (SE) animals. Normotopic SE animals possessed an HBD (SE + cells) not − cells). Apical dendrites were stimulated using multiphoton uncaging glutamate. Two‐photon Ca 2+ imaging was used measure transients associated with back‐propagating action potentials (bAPs). Results Near‐synchronous synaptic input integrated linearly apical significantly different cells. majority linearly, similar However, 2 11 capable supralinear mediated by dendritic spike. Furthermore, bAP‐evoked relatively well maintained along HBDs, compared This further suggests enhanced electrogenesis HBDs. addition, output epileptic tissue enhanced, both displaying increased high‐frequency (>100 Hz) burst‐firing. Finally, received recurrent excitatory generating APs, especially absence feedback inhibition. Significance Taken together, data suggest excitability combined altered collude promote synchrony