Previous double-stainings in the cat visual cortex [E. Van der Gucht, S. Clerens, K. Cromphout, F. Vandesande, L. Arckens, Differential expression of c-fos in subtypes of GABAergic cells following sensory stimulation in the cat primary visual cortex, Eur. J. Neurosci. 16 (2002) 1620-1626] showed that a minority of Fos-immunoreactive nuclei was located in distinct subclasses of inhibitory neurons following sensory stimulation. This report describes double-stainings between Fos and phosphate-activated glutaminase (PAG) or Fos and neurofilament protein (SM1-32) revealing that, following a short-term visual experience, Fos is also expressed in neurochemically distinct subpopulations of non-GABAergic, pyramidal neurons in supra- and infragranular layers of cat area 17. (c) 2004 Elsevier B.V. All rights reserved.