NE induces persistent firing in pyramidal neurons of prefrontal cortex via activation of α1 adrenoceptors.

<p>(A) Left: Schematic diagram of a coronal section of rat brain showing the recorded area (dots) in the prefrontal cortex including the rostral anterior cingulate cortex (ACC) and prelimbic cortex (PrL). Adapted from Paxinos and Watson (1998). Right: Typical video image of a brain slice showing the recording site (with a patch electrode) at layer 2/3 of the ACC subdivision of the prefrontal cortex. (B) Sample trace of NE (10 µM)-induced plateau potential and persistent firing following a depolarizing current pulse in a pyramidal neuron. (C) In another group of neurons, NE failed to induce neuronal responses (non-responsive cell, left panel). However, application of carbachol (CCh 10 µM) evoked persistent firing in the same neurons after NE washout (right panel). (D) Quantification of frequency and amplitude of plateau potential of the NE (10 µM, n = 7) and CCh (10 µM, n = 9) effects. (E) NE-evoked persistent firing (NE) is blocked by the selective α1 adrenoceptor antagonist prazosin (2 µM, NE+Praz, n = 6). (F) The selective α1 adrenoceptor agonist phenylephrine (PE, 10 µM, n = 10) also induced NE-like persistent firing in pyramidal neurons of the prefrontal cortex. (G) Quantification of frequency and amplitude of plateau potential of the prazosin and phenylephrine effects shown in E and F. Values are mean ± SEM. *** p<0.001. The dashed line in panel B, C, E and F represents the membrane potential at −60 mV. The short horizontal bar (2 s) underneath the recording trace represents the current pulse stimulation. The description on dashed line and short horizontal bar also applies to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066122#pone-0066122-g002" target="_blank">Figures 2</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066122#pone-0066122-g003" target="_blank">3</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066122#pone-0066122-g005" target="_blank">5</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066122#pone-0066122-g006" target="_blank">6</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066122#pone-0066122-g007" target="_blank">7</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066122#pone-0066122-g008" target="_blank">8</a>.