Santini E, Quirk GJ, Porter JT. Fear conditioning and extinction differentially modify the intrinsic excitability of infralimbic neurons. J Neurosci. 2008 Apr 9;28(15):4028-36. Impact Factor (as of 2005): 7.510.
 

Mueller D, Porter JT, Quirk GJ. Noradrenergic signaling in infralimbic cortex increases cell excitability and strengthens memory for fear extinction. J Neurosci. Jan 9, 2008;28(2):369-375. Impact Factor (as of 2005): 7.510.