Cytochrome Oxidase and Functional Coding in Primate Striate Cortex: A Hypothesis

In 1978, Margaret Wong-Riley stained sections of squirrel monkey striate cortex for the activity of the mitochondrial enzyme, cytochrome oxidase, and noticed a periodic distribution of “puffs” of increased enzyme activity in layers 2 and 3 (letter to D. Hubel cited in Livingstone and Hubel [1984]). Her discovery anticipated a whole series of anatomical and physiological findings from many laboratories that correlated with the distribution of this enzyme in the striate cortex of primates, yet there has never been a satisfactory explanation as to why the distribution of this enzyme, crucial for aerobic energy metabolism, would be related to the functional organization of visual cortex (Martin 1988). The puffs have also been called blobs, spots, dots, and patches, with the term blob used most frequently.