Evidence that primary visual cortex is required for image, orientation, and motion discrimination by rats.

TitleEvidence that primary visual cortex is required for image, orientation, and motion discrimination by rats.
Publication TypeJournal Article
Year of Publication2013
AuthorsPetruno SK, Clark RE, Reinagel P
JournalPLoS One
Date Published2013
KeywordsAnimals, Discrimination (Psychology), Discrimination Learning, Male, Motion, Orientation, Photic Stimulation, Psychomotor Performance, Rats, Visual Cortex

The pigmented Long-Evans rat has proven to be an excellent subject for studying visually guided behavior including quantitative visual psychophysics. This observation, together with its experimental accessibility and its close homology to the mouse, has made it an attractive model system in which to dissect the thalamic and cortical circuits underlying visual perception. Given that visually guided behavior in the absence of primary visual cortex has been described in the literature, however, it is an empirical question whether specific visual behaviors will depend on primary visual cortex in the rat. Here we tested the effects of cortical lesions on performance of two-alternative forced-choice visual discriminations by Long-Evans rats. We present data from one highly informative subject that learned several visual tasks and then received a bilateral lesion ablating >90% of primary visual cortex. After the lesion, this subject had a profound and persistent deficit in complex image discrimination, orientation discrimination, and full-field optic flow motion discrimination, compared with both pre-lesion performance and sham-lesion controls. Performance was intact, however, on another visual two-alternative forced-choice task that required approaching a salient visual target. A second highly informative subject learned several visual tasks prior to receiving a lesion ablating >90% of medial extrastriate cortex. This subject showed no impairment on any of the four task categories. Taken together, our data provide evidence that these image, orientation, and motion discrimination tasks require primary visual cortex in the Long-Evans rat, whereas approaching a salient visual target does not.

Alternate JournalPLoS ONE
PubMed ID23441202
PubMed Central IDPMC3575509
Grant ListR01 5R01EY016856 / EY / NEI NIH HHS / United States
IRG Funded