Pattern Of Cytochrome Oxidase Activity Research Articles

Organization of Hue Selectivity in Macaque V2 Thin Stripes

V2 has long been recognized to contain functionally distinguishable compartments that are correlated with the stripelike pattern of cytochrome oxidase activity. Early electrophysiological studies suggested that color, direction/disparity, and orientation selectivity were largely segregated in the thin, thick, and interstripes, respectively. Subsequent studies revealed a greater degree of homogeneity in the distribution of response properties across stripes, yet color-selective cells were still found to be most prevalent in the thin stripes. Optical recording studies have demonstrated that thin stripes contain both color-preferring and luminance-preferring modules. These thin stripe color-preferring modules contain spatially organized hue maps, whereas the luminance-preferring modules contain spatially organized luminance-change maps. In this study, the neuronal basis of these hue maps was determined by characterizing the selectivity of neurons for isoluminant hues in multiple penetrations within previously characterized V2 thin stripe hue maps. The results indicate that neurons within the superficial layers of V2 thin stripe hue maps are organized into columns whose aggregated hue selectivity is closely related to the hue selectivity of the optically defined hue maps. These data suggest that thin stripes contain hue maps not simply because of their moderate percentage of hue-selective neurons, but because of the columnar and tangential organization of hue selectivity.

Some aspects of the modular organization of the primary visual cortex of the cat: Patterns of cytochrome oxidase activity

The distribution of the enzyme cytochrome oxidase (CO) in continuous series of parasagittal sections from field 17 and frontal sections of the dorsal nucleus of the lateral geniculate body (LGB) from normal kittens and adult cats was studied. In all cats apart from neonates, layer IV showed regularly alternating areas with above-background levels of CO activity ("spots"). There was a significant increase in the contrast of the "spots" from days 13 to 21, which was followed by a significant decrease from days 48 to 93. These changes coincided with ontogenetic changes in the level of visual system plasticity. There were no differences in CO activity between layers A and A1 of the dorsal nucleus of the LGB. It is suggested that the non-uniform distribution of the level of functional activity of neurons in field 17 reflects the formation of columnar cortical structures during the critical period of postnatal ontogenesis.

Complete flatmounting of the macaque cerebral cortex.

The elaborate folding of the brain surface has posed a practical impediment to investigators engaged in mapping the areas of the cerebral cortex. This obstacle has been overcome partially by the development of methods to erase the sulci and gyri by physically flattening the cortex prior to sectioning. In this study, we have prepared a step-by-step atlas of the flatmounting process for the entire cerebral cortex in the macaque monkey. The cortex was dissected from the white matter, unfolded, and flattened in a single piece of tissue by making three relieving cuts. The flatmount was sectioned at 60-75 microm and processed for cytochrome oxidase (CO) or myelin. From animal to animal there was nearly a twofold variation in the surface area of individual cortical regions, and of the whole cortex. In each specimen, a close correlation was found between V1 surface area (mean = 1343 mm2), V2 surface area (mean = 1012 mm2), hippocampal area (mean = 181 mm2), and total cerebral cortex area (mean = 10,430 mm2). The complete pattern of CO stripes in area V2 was labeled clearly in several cases; the number of cycles of thick-pale-thin-pale stripes ranged from 26 to 34. Characteristic patterns of strong CO activity were encountered in areas V3, MT, auditory and somatosensory cortex. In some animals we made injections of a retrograde tracer, gold-conjugated cholera toxin B subunit, into area V2 to identify all sources of cortical input. In addition to previously described inputs, we identified three new regions in the occipitotemporal region that project to V2. Flatmounting the cerebral cortex is a simple, efficient method that can be used routinely for mapping areas and connections in the macaque brain, the most widely used primate model of the human brain.

A metabolic map of cytochrome oxidase in the rat brain: histochemical, densitometric and biochemical studies.

To examine brain patterns of metabolic and functional activity, the distribution of cytochrome oxidase, a mitochondrial enzyme marker for neuronal functional activity, was mapped throughout the rat brain. Mapping was done qualitatively by enzyme histochemistry of brain sections cut in three planes (coronal, sagittal and horizontal), and quantitatively by optical densitometry of stained sections and by biochemical assays of brain tissue homogenates. Activity of the enzyme was distributed in characteristic patterns and amounts that differed among various neural pathways, brain nuclei, cerebral cortical areas and layers, and neuron types. Gray matter essentially always had higher enzyme activity than did white matter, by a factor of eight- to 12-fold. Among different neural pathways, cytochrome oxidase activity was relatively high in special sensory, somatosensory and motor systems, and was relatively low in associative, limbic, autonomic and visceral regulatory systems (though exceptional areas were present). Among 11 different neuron types, nearly a two-fold range of histochemical staining intensities was observed, with the darkest staining in neurons of the mesencephalic trigeminal nucleus. The observed patterns of cytochrome oxidase activity were mostly similar to the patterns of 2-deoxyglucose uptake seen previously [Schwartz W. J. and Sharp F. R. (1978) J. comp. Neurol. 177, 335-360; Sokoloff L. et al. (1977) J. Neurochem. 28, 897-916] in conscious, "resting" animals, though some differences were found. For example, whereas 2-deoxyglucose uptake was about three-fold higher in gray matter than in white matter [Sokoloff L. et al. (1977) J. Neurochem. 28, 897-916], cytochrome oxidase activity was about eight- to 12-fold higher. This and other discrepancies probably reflect basic technical differences between these two methods. Compared to 2-deoxyglucose, cytochrome oxidase is more specific for oxidative rather than glycolytic metabolism, and more reflective of overall neuronal functional activity occurring over longer time periods lasting hours to weeks, rather than minutes. The anatomical resolution of cytochrome oxidase histochemistry is also finer than that of 2-deoxyglucose autoradiography, extending to the electron microscopic level. The metabolic map of cytochrome oxidase activity reveals patterns of normal brain function, and may be useful as a baseline for comparison in studies of brain disease, development, ageing and plasticity.

Modular organization of human extrastriate visual cortex: evidence from cytochrome oxidase pattern in normal and macular degeneration cases.

The human extrastriate occipital cortex contains several visual areas that are probably analogues of macaque areas V2, V3, VP, V4 and V5. Tracing of callosal connections has led to the anatomical identification of these areas and to the characterization of some of them by cyto- and myeloarchitecture (Clarke and Miklossy, 1990). The pattern of cytochrome oxidase activity in these visual areas is now described in a normal case and in a case of age-related bilateral macular degeneration. In normal cortex, the laminar distribution of cytochrome oxidase activity was similar in V2, V3, VP, V4 and V5; a prominent dark band covered most of layers III and IV, and its upper and lower limits were gradual. In V2, V3, V4 and V5 but not VP, layer II tended to be darker than the infragranular layers. The overall intensity of the staining varied between areas: VP was very light, V2, V3 and V4 were darker, and V5 was very dark. A different, two-band pattern of cytochrome oxidase activity was found in a restricted region of the posterosuperior precuneus. The bilateral age-related macular degeneration had led to a great loss of ganglion cells in the central, but not in the peripheral retinae. The central representation in the lateral geniculate nuclei showed abnormally weak staining for cytochrome oxidase, particularly in the parvocellular layers. In the cortex, the contrast between lightly and darkly stained regions was greater than in the normal case. In particular, V5 was very heavily stained, and in V1 and V2 there were two different types of dark stripes that may represent compartments driven predominantly by the magnocellular system.

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.

The fronto-parietal cortex of the prosimian Galago: Patterns of cytochrome oxidase activity and motor maps

We mapped the motor areas of the prosimian Galago crassicaudatus using intracortical electrical microstimulation and morphological and histochemical (cytochrome oxidase) techniques. Stimulation data showed that on the brain convexity there is an area (area Frontalis posterior, F post.) from which movements could be evoked at low threshold (< 10 μA. This area is somatotopically organized, with the leg represented medially, the arm centrally and the face and mouth laterally. Proximal and distal movements are not segregated. Most of the evoked movements, even at threshold, consist of movements involving two or more joints. F post. is characterized by a three-band cytochrome oxidase activity pattern. It has an agranular structure, but it lacks pyramidal cells that are larger than those observed in other areas. In front of F post. there is an area histochemically similar to it, Frontalis intermedialis (F int.). This area consists of two cytoarchitectonic divisions: an agranular division (F int. pars caudalis) and a disgranular division (F int. pars rostralis). The excitability threshold of F int. is relatively high (10 to 30 μA). Eye, ear and neck movements are elicited from its lateral part, whereas trunk movements associated with limb movements are elicited from its medial part. Caudal to F post., there is another region from which movements can be evoked with currents between 10 to 30 μA. This region has the same medio-lateral somatotopic arrangement of F post. Typically, single joint movements are elicited from it. Proximal and distal movements are not segregated. In spite of its homogeneity in terms of motor response, the posterior excitable region is formed by two anatomically separate areas: anterior somatic area (S ant.) and posterior somatic area (S post.). S ant. has a typical koniocortex structure, whereas S post. resembles the parakoniocortex as defined by Sanides ( J. Hirnforsch., 9 (1967) 225–252). Histochemically both areas are made up of four longitudinal stripes differing for enzymatic activity. The three superfical stripes tend to merge together and are sharply separated from a deeply located, light stripe. This stripe is homogeneous in S ant., whilst its central part shows an increase in activity in S post. The possible homologies between the motor and somatic areas of the galago and monkey as well as their role in movement control are discussed.

Amblyopia induced by anisometropia without shrinkage of ocular dominance columns in human striate cortex.

Amblyopia can be induced by opacity of the ocular media (e.g., cataract), misalignment of the ocular axes (strabismus), or unequal refractive error in the eyes (anisometropia). Experiments in monkeys have shown that early monocular eyelid suture, a model of amblyopia caused by cataract, results in shrinkage of the eye's ocular dominance columns in striate cortex. This reduction of the geniculocortical projection from the deprived eye has been thought to explain in part the mechanism of amblyopia. We labeled the ocular dominance columns in monkeys with amblyopia by using cytochrome oxidase histochemistry. In animals rendered amblyopic by early unilateral eyelid suture, no pattern of cytochrome oxidase activity appeared in layer IVc. Outside layer IVc, alternating rows of light and dark patches were present; the pale patches fit in register with the shrunken ocular dominance columns of the deprived eye, which were labeled by autoradiography. Subsequent removal of one eye caused a striking cytochrome oxidase pattern to emerge in layer IVc that correlated precisely with the shrunken (deprived eye) and expanded (normal eye) ocular dominance columns. This correlation was shown by injecting one eye with [3H]proline. It has remained unsettled whether other forms of amblyopia are accompanied by shrinkage of ocular dominance columns. To address this issue, in an analogous clinical case, we examined the pattern of cytochrome oxidase activity in a human subject with a history of anisometropic amblyopia who suffered a lesion of one optic nerve shortly before death. The ocular dominance columns were normal in width, indicating that some forms of amblyopia occur without shrinkage of ocular dominance columns.

Effects of cortical and thalamic lesions upon primary afferent terminations, distributions of projection neurons, and the cytochrome oxidase pattern in the trigeminal brainstem complex

Early postnatal lesions of the primary somatosensory cortex alter the vibrissa-related cytochrome oxidase (CO) pattern in nucleus principalis (PrV) of the rat's trigeminal (V) brainstem complex (Erzurumlu and Ebner, '88: Dev. Brain Res. 44:302-308). At present, the reason for this change is not clear. It may be that the corticotrigeminal projection is necessary for the maintenance of vibrissa-related patterns in PrV. However, it is also possible that the loss of the normal pattern of CO activity reflects a change in the organization of brainstem cells resulting from transneuronal retrograde degeneration. In order to address this question, we made lesions of either the primary somatosensory cortex (S-I) or ventrobasal thalamus (VB) in newborn rats and directly assayed distribution of V primary afferents by transganglionic transport of horseradish peroxidase and V-thalamic neurons by retrograde transport of either fluorogold or true blue. Neonatal cortical and thalamic lesions produced no qualitative change in the distribution of primary afferent terminals in either PrV or V subnucleus interpolaris (SpI) beyond that which could be attributed to shrinkage of the brainstem resulting from retrograde degeneration. Most importantly, the "patchy" pattern of terminations observed in normal rats remained apparent in the brain-damaged animals. The normal distribution of V-thalamic neurons in PrV was disrupted by both cortical and thalamic lesions. These cells are normally patterned in a way that matches the distribution of primary afferent terminals and thus that of the mystacial vibrissae. This was not the case in the neonatally brain-damaged rats. Taken together, these results are consistent with the conclusion that neonatal cortical and thalamic lesions disrupt the normal CO pattern in PrV primarily because of their effects upon the patterning of brainstem cells. The present findings demonstrate further that clustering of primary afferents does not require a normal complement of postsynaptic neurons.

Regulation of cytochrome oxidase protein levels by functional activity in the macaque monkey visual system

The activity of cytochrome oxidase (CO), a mitochondrial enzyme of oxidative energy metabolism, is regulated by nerve cell functional activity. The mechanism of CO activity regulation was studied using histochemical and immunohistochemical methods to show the distributions of CO activity and protein, respectively, in the macaque monkey visual system under normal and experimental conditions. In normal animals, patterns of CO activity were found to reflect underlying patterns of CO protein distribution; for example, puffs of high CO activity in cortical area 17 contained high levels of CO protein. Experimental animals were injected monocularly with TTX for 3-4 weeks; this treatment blocks retinal impulses in the injected eye and results in decreased CO activity in lateral geniculate laminae and striate cortical columns normally driven by the treated eye. The experimentally induced decreases in CO activity were also found to reflect underlying parallel decreases in CO protein levels. These results suggest that CO activity is regulated mainly at the level of the local amount rather than the turnover number of the enzyme and imply that the rates of CO synthesis and/or degradation are regulated by neural functional activity.

Transient patterns of GAP‐43 expression during the formation of barrels in the rat somatosensory cortex

The development of the rat barrel field cortex was investigated with an antibody to the axonal membrane-specific phosphoprotein GAP-43 in order to examine the developmental pattern of afferent projections, and with cytochrome oxidase histochemistry and Nissl stains to reveal the morphogenesis of cortical barrels. On the first two days after birth, GAP-43 immunostaining in the cortical plate was light and diffuse, then became intense in the presumptive layer IV of the parietal cortex on PND3 (day of birth = PND0). Immunoreactive densities were visible as small, focal patches within the centers of prospective barrels. These densities increased in size and intensity over the next few days and then diminished abruptly. On PND7, the distribution of GAP-43 was coextensive with barrels, as defined by cytochrome oxidase histochemistry and Nissl staining. GAP-43 virtually disappeared from the barrels after PND7. From the second postnatal week, GAP-43 immunostaining was evident in the septa between barrels and in the dysgranular regions of SI cortex. This pattern of GAP-43 distribution was complementary to the pattern of cytochrome oxidase activity, and persisted into maturity. In an attempt to identify possible source(s) of GAP-43 positive afferents in the developing barrels, we examined the effects of altering the sensory periphery on the distribution of GAP-43 immunostaining in the cortex. Rat pups had row C whiskers cauterized on PND0 and were sacrificed on PND3 or PND5. Whereas immunopositive densities corresponding to intact whiskers developed in a normal, punctate pattern, cortical representation of the lesioned whiskers formed a continuous band of labeling that was evident as early as PND3. We argue that the disjunctive expression of GAP-43 in the barrel field reflects the pattern of distribution of afferents (most likely from the ventro-basal thalamic nucleus) to the barrel field cortex, and that this pattern may be instructive in the formation of barrels as cytoarchitectonic units. The rapid alteration in patterns of immunostaining following whisker lesions lends further support to the conclusion that the "barrel template" is conveyed to the neocortex by incoming afferents. The possible significance of the transient expression of GAP-43 in the maturing barrel field is discussed.

Maintenance of discrete somatosensory maps in subcortical relay nuclei is dependent on an intact sensory cortex

Lesions of the rat barrelfield cortex drastically alter the discrete representations of the somatosensory periphery in the central nervous system. We have found that lesions placed in the parietal cortex, after the formation of barrels (postnatal day 5), can irreversibly abolish vibrissae- and extremity-related patterns of cytochrome oxidase activity in the principal sensory nucleus of the trigeminal nerve and in the dorsal column nuclei. Furthermore, abnormal patterns of enzymatic activity occur in the remaining primary somatosensory cortex and the ventrobasal nucleus of the thalamus. We conclude that cortical barrels are essential in maintenance of periphery-related discrete morphological organization in the rodent somatosensory system.

Changes of cytochrome oxidase activity in the rat subcortical visual centers after unilateral eye enucleation

Histochemical densitometric measurements of cytochrome oxidase (CO) activity in the dorsal and ventral lateral geniculate nuclei (LGNd and LGNv) and the superficial gray stratum of the superior colliculus (SC) were done between 2 and 12 weeks after unilateral enucleation in the adult albino rat. This deafferentation resulted in a transient, slight but statistically significant decrease in CO activity in the contralateral LGNd and LGNv. Whereas in the contralateral SC, a marked reduction in CO activity was observed, and this persisted over the postoperative periods studied. The regional difference in the recovery pattern of CO activity were discussed from the aspect of synaptic reorganization.

Histochemical demonstration of vibrissae-representing patchy patterns of cytochrome oxidase activity within the trigeminal sensory nuclei in the cat

Cytochrome oxidase histochemistry revealed patchy patterns of the enzyme activity in transverse sections through the caudal part of the ventral subnucleus of the principal sensory trigeminal nucleus, interpolar spinal trigeminal nucleus, and layer IV of the caudal spinal trigeminal nucleus in the cat. By the transganglionic transport method of horseradish peroxidase, the patterns were indicated to replicate the spatial array of the facial vibrissae.

Cytochrome oxidase activity in the striate cortex and lateral geniculate nucleus of the newborn and adult macaque monkey.

The laminar location of cytochrome oxidase staining has been compared in the lateral geniculate nucleus and area 17 in newborn and adult macaque monkeys. In area 17 of the adult, the distribution of cytochrome oxidase activity confirmed published findings. In the newborn animals, the tissue reacted as strongly for cytochrome oxidase as in the adult but the pattern of labelling was different in two respects. Firstly in layer 1 activity was stronger and occupied a wider portion of this layer. Secondly, cytochrome oxidase staining in layer 4C occupied two separate bands, a small narrow band at the bottom of 4C beta and a wider one occupying the full width of 4C alpha and spilling over into 4B. The pattern of cytochrome oxidase activity did not appear to be influenced by eccentricity in the newborn whereas, in the adult, label in 4C was more intense in cortex subserving central vision. In the lateral geniculate nucleus of the adult, the magnocellular layers and the most dorsal parvocellular layer reacted most strongly for cytochrome oxidase. In the newborn, parvocellular layers were more uniformly labelled and the difference between parvo- and magnocellular layers more pronounced. These results are discussed in relationship to the development of thalamo-cortical projections in the monkey.

Patterns of cytochrome oxidase activity in the frontal agranular cortex of the macaque monkey

The laminar pattern of cytochrome oxidase activity was studied in the agranular frontal cortex (area 4–6 complex) of the macaque monkey. The cortex, stained with this method, showed 6 stripes of different enzymatic activity. On the basis of their characteristics and of the presence of highly active cells, the agranular frontal cortex could be parcellated in 5 areas (F1–F5). F1 very likely corresponds to area FA of von Bonin and Bailey. Rostral to F1 two large regions could be distinguished, one located medial to the spur of the arcuate sulcus and its imaginary caudal extension, the other laterally. The superior region was formed by areas F2 and F3. The first was located on the dorsomedial cortical surface, the other on the mesial surface. F3 possibly corresponds to the supplementary motor area. The inferior region was formed by areas F4 and F5. The rostral area (F5) showed transition characteristics that rendered it somehow similar to the prefrontal areas. It may correspond to the cytoarchitectonic area FCBm. The cytocrome oxidase technique is a useful means of parcellating the agranular frontal cortex and may greatly help in physiological and behavioral experiments.

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.

Projection pattern of functional components of thalamic ventrobasal complex on monkey somatosensory cortex

Projection pattern of functional components of thalamic ventrobasal complex on monkey somatosensory cortex

Cytochrome oxidase deficiency during development of amphibian nucleocytoplasmic hybrids

The activity of mitochondrial cytochrome oxidase was investigated during the embryonic development of nucleocytoplasmic hybrids containing a nuclear genome derived from R. pipiens and a mitochondrial genome derived from R. palustris. Using a quantitative cytochemical approach, we found that the activity of cytochrome oxidase failed to increase during the development of these embryos. Control embryos containing a haploid chromosomal complement, derived from the same species as that from which the maternally inherited mitochondria is derived and hybrid crosses between R. palustris and R. pipiens, showed a significant increase in cytochrome oxidase activity during development. Oxygen uptake data from diploid and haploid R. pipiens embryos were in agreement with the data obtained by the cytochemical method. These results indicate that a normal pattern of cytochrome oxidase activity during embryonic development requires a nuclear genome which contains a haploid chromosomal complement derived from the same species as that from which the mitochondrial genome is derived.