Molecular NeuroscienceRat visual cortical neurones express TrkA NGF receptorTropea, Daniela1; Capsoni, Simona2; Covaceuszach, Sonia2; Domenici, Luciano1 3; Cattaneo, Antonino2 CAAuthor Information 1Cognitive Neuroscience Sector 2Biophysics Sector, Neuroscience Program, International School for Advanced Studies (SISSA), Via Beirut 2-4, 34014 Trieste 3Institute of Neurophysiology (CNR), Via Moruzzi 1, 56100 Pisa, Italy CACorresponding Author Received 15 March 2002 accepted 24 April 2002 Neuroreport: July 19, 2002 - Volume 13 - Issue 10 - p 1369-1373 Buy Abstract In this study we report the expression of TrkA receptor within the rat visual cortex during postnatal development and in adulthood, using a specific monoclonal antibody which recognizes the extracellular domain of TrkA receptor. TrkA was not detected by immunohistochemistry at postnatal day 13 (P13), i.e. before eye opening. At P22 TrkA was mostly localised in cortical fibre-like processes. At P39 and P90, TrkA-positive neuronal cell bodies in supragranular and infragranular layers were found. Using double immunohistochemistry, labelled cells were identified as intrinsic cholinergic neurones, and as interneurones expressing calbindin and neuropeptide Y. We conclude that TrkA is expressed in visual cortical neurones during postnatal development and in adulthood and that its pattern of expression is developmentally regulated. © 2002 Lippincott Williams & Wilkins, Inc.