ECoG effects of peripheral deafferentation of prepyriform and visual cortices in rats

Freely-behaving Wistar albino male rats were prepared for chronic recording of the electrocorticographic (ECoG) activity of neo- and paleocortical areas and of the electromyogram of dorsal neck muscles. The effects of the uni- or bilateral removal of the main olfactory bulbs and adjacent structures on the prepyriform cortex (PPC) ECoG, and the possible ECoG modifications in the area 17 after bilateral eye enucleation were studied. In spite of the fact that the PPC general cycling pattern along the sleep-wakefulness cycle (SWC) was not appreciably affected by the olfactory deafferentation, this experimental maneuver did cause very marked alterations in the PPC ECoG during all of the observed SWC phases. On the other hand, no appreciable ECoG modifications could be detected in area 17 after the visual deafferentation. A comparison of these results with pertinent literature for cats and monkeys allows the formulation of some working hypotheses that deserve experimental testing in the future.