Fig. 3. The appearance of activated caspase-3-stained neurons in layer II (A and B ) and layer V (C ) of the primary visual cortex of an isoflurane-exposed brain. Layer II profiles have the shape and arborization pattern characteristic of γ-aminobutyric acid-ergic inhibitory interneurons. Layer V profiles are predominantly small pyramidal neurons (presumably glutamatergic) of a type that are thought to project to visual neurons in the contralateral hemisphere.32The large activated caspase-3-positive multipolar neuron in C was seen occasionally in layer V and more frequently in the superficial portion of layer VI. This cell has the appearance of a Martinotti cell, which has been described as γ-aminobutyric acid-ergic33and is thought to mediate inhibition.