Activity correlates of cytochrome oxidase-defined compartments in granular and supragranular layers of primary visual cortex of the macaque monkey. Vis Neurosci 1995;12(4):629-39
Date
07/01/1995Pubmed ID
8527365DOI
10.1017/s0952523800008920Scopus ID
2-s2.0-0029328594 (requires institutional sign-in at Scopus site) 49 CitationsAbstract
To determine if changes in metabolic capacity revealed by cytochrome oxidase (CO) histochemistry are related to sustained changes in energy-utilizing neuronal activity, we assayed CO levels and recorded multiunit firing rates along nearly tangential penetrations of V1 in seven adult macaque monkeys before and after single, monocular injections of TTX. Within as little as 14 h, TTX blockade began to reduce CO staining in zones of layer 4C that received dominant input from the injected eye. Since simple monocular occlusion has only minor effects on cortical CO levels (Trusk et al., 1990), the changes in activity that were specifically associated with CO depletion were isolated by comparing spike rates during monocular TTX blockade and during monocular occlusion. Five second samples of multiunit spike rate were obtained after 2-min adaptation to each of four adapting fields: black, gray, white, and textured. Results were similar for these four conditions. In layer 4C, ocular dominance zones with input from the TTX eye had ongoing spike rates that were 48% of the rates in zones with input from a normal but occluded eye. In six animals, it was possible to record activity at a single site before, during, and after the onset of TTX blockade. Background activity at these interpuff sites decreased as much as 3-fold in less than 1 h but stabilized within 3-4 h to an average of 53% of pre-TTX rates. These data support the interpretation that energy utilization linked to sustained spike rates partially regulates CO levels under normal conditions, at least in layer 4. Furthermore, changes in neuronal activity induced by retinal TTX preceded the detectable reduction in CO activity in V1 suggesting that the adjustment of CO levels was in response to the altered activity.
Author List
Deyoe EA, Trusk TC, Wong-Riley MTAuthor
Edgar A. DeYoe PhD Adjunct Professor in the Radiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Action PotentialsAnimals
Dominance, Cerebral
Electron Transport Complex IV
Histocytochemistry
Macaca mulatta
Microelectrodes
Neurons
Retina
Tetrodotoxin
Vision, Monocular
Visual Cortex
Visual Pathways
Visual Perception