TY - JOUR T1 - Brain State Dependent Postinhibitory Rebound in Entorhinal Cortex Interneurons JF - The Journal of Neuroscience JO - J. Neurosci. SP - 6501 LP - 6510 DO - 10.1523/JNEUROSCI.5871-11.2012 VL - 32 IS - 19 AU - Mohit H. Adhikari AU - Pascale P. Quilichini AU - Dipanjan Roy AU - Viktor Jirsa AU - Christophe Bernard Y1 - 2012/05/09 UR - http://www.jneurosci.org/content/32/19/6501.abstract N2 - Postinhibitory rebound (PIR) is believed to play an important role in the genesis and maintenance of biological rhythms. While it has been demonstrated during several in vitro studies, in vivo evidence for PIR remains scarce. Here, we report that PIR can be observed in the dorsomedial entorhinal cortex of anesthetized rats, mostly between putatively connected GABAergic interneurons, and that it is more prevalent during the theta (4–6 Hz) oscillation state than the slow (0.5–2 Hz) oscillation state. Functional inhibition was also found to be brain state and postsynaptic cell type dependent but that alone could not explain this brain state dependence of PIR. A theoretical analysis, using two Fitzhugh–Nagumo neurons coupled to an external periodic drive, predicted that the modulation of a faster spiking rate by the slower periodic drive could account for the brain state dependence of PIR. Model predictions were verified experimentally. We conclude that PIR is cell type and brain state dependent and propose that this could impact network synchrony and rhythmogenesis. ER -