Cytochrome Oxidase Activity In Areas Research Articles

Distribution of cytochrome oxidase and parvalbumin in the primary visual cortex of the adult and neonate monkey, Callithrix jacchus

The anatomical distributions of the mitochondrial enzyme cytochrome oxidase (CO) and of the calcium binding protein parvalbumin (PV) were studied in the striate cortex of adult and neonate New World monkeys (Callithrix jacchus). In the adult marmoset, both proteins were found in laminar arrangements similar to those described for the macaque monkey, with prominent bands of PV-like immunoreactive (PV-LI) puncta in layers IV and IIIb, and fairly evenly distributed PV-LI nonpyramidal neurons. Furthermore, the pattern of CO activity in area 17 of the neonate marmoset was almost identical to the CO pattern described in neonate macaque and squirrel monkeys. It came, therefore, as a surprise to find that the adult pattern of PV-like immunoreactivity (PV-LI) in the marmoset striate cortex arises from a neonatal pattern strikingly different from that seen in any developmental stage of the macaque, or in any other mammal studied so far. In the deep layers IV through VI of the neonate marmoset, a large number of PV-LI neurons was stained in bandlike patterns, their number in layers IV and V exceeding the number of PV-LI neurons present in these layers of the adult marmoset area 17. Staining of layers IV and VI was restricted to area 17 and involved nonpyramidal cells and their processes. The stained band of layer V, in contrast, continued throughout most of the neocortex. In area 17, an estimated 10 to 20% of the stained cells in layer V exhibited pyramidal shapes. The findings show that the expression of PV by visual cortical cells occurs before birth and suggest that the comparatively early onset of PV expression is not dependent on the onset of textured vision. The exuberant number of stained cells in some layers, and particularly the staining of pyramidal cells, in the neonate marmoset, suggest that a considerable number of cells possesses the stainability for PV-LI only transiently, i.e., in the marmoset, these cells have a specific demand for parvalbumin during this phase of their development.

Organization of cytochrome oxidase staining in the visual cortex of nocturnal primates (Galago crassicaudatus and Galago senegalensis): I. Adult Patterns

The distribution and differential staining patterns of cytochrome oxidase (CO) activity in visual cortical areas have provided useful anatomical markers for the modular organization of area 17 (striate cortex) and area 18 in primates. In macaque and squirrel monkeys, previous studies have shown that the majority of cells that lie in areas of high CO activity are color selective, are nonoriented, and project to adjacent zones of high CO activity in area 17 and to stripes of high CO activity in area 18. By contrast, most cells in zones with weak CO activity in area 17 have relatively narrow orientation tuning and are not color selective (Livingstone and Hubel: J. Neurosci. 4:309-356, 2830-2835, '84; 7:3371-3377, '87). The periodic organization of CO activity in area 17, the "blobs," and the stripe-like organization in area 18 thus seem to define visual cortical processing modules and/or channels in primates. We have investigated the organization of CO activity in areas 17 and 18 in two species of nocturnal prosimian primates [Galago crassicaudatus (GCC) and Galago senegalensis (GSS)] in order to evaluate CO staining patterns in primates that have been reported to possess almost exclusively rod retinae and no color vision. In area 17 of both species, our results show that, as in diurnal and nocturnal simian primates, the darkest CO staining occurs in layers III and IV, with clear periodicity in layer III (i.e., CO blobs) and homogeneous staining in layer IV beta, the cortical recipient sublayer of the geniculate parvocellular layers. In GCC, individual blobs in layer III appear to be larger and less frequent than has been reported for the macaque monkey. Unlike simian primates, both galago species exhibit clear CO periodicities within layer IV alpha, the cortical recipient sublayer of the magnocellular geniculate layers. In addition, faint CO periodicities are apparent in layer VI and scattered large darkly CO stained pyramidal cells are visible throughout layer V. Quantitative analysis suggests that CO periodicities are more frequent in GSS than in GCC, suggesting that there may be evolutionary pressure to maintain the same number of CO modules within the smaller striate cortex of the lesser galago, although this is not the trend found across distantly related species. CO activity in area 18 is less well-developed than reported in other primates. In fact, we could not reliably identify discontinuities in CO staining in area 18 of GSS.(ABSTRACT TRUNCATED AT 400 WORDS)

Patterns of cytochrome oxidase activity in areas 17, 18 and 19 of the visual cortex of cats and kittens.

The laminar pattern of cytochrome oxidase activity was studied in visual cortical areas 17, 18 and 19 in adult cats and kittens, following electrophysiological determination of the boundaries of these areas in all but the youngest animals. The patterns of cytochrome oxidase staining and the cytoarchitectonic appearances of areas 17, 18 and 19 were compared. At all ages activity was especially high in the region of layers IV and VI in areas 17 and 18, and was low in all laminae in area 19. The results suggest that the degree of cytochrome oxidase activity in these regions of the visual cortex may be related to the strength and type of projection that they receive from the lateral geniculate nucleus. The cytochrome oxidase technique is a useful means of defining the 18/19 border, and may help locate the boundary between areas 17 and 18, in both adult cats and kittens.