Intrahousehold empowerment gaps and dietary diversity in China

Objective

This article analyzes the relationship between intrahousehold empowerment gaps and food and nutrition security using quantitative data collected through a household survey organized by the Agricultural Information Institute, Chinese Academy of Agricultural Sciences (CAAS-AII), in 2023.

Methods

Based on empowerment theory, this study measured the relative empowerment of spouses from the Abbreviated Women's Empowerment in Agriculture Index (A-WEAI).

Results

From the micro-level evidence of 468 rural households, this study found that intrahousehold empowerment gaps harm the diversity of household diets. In particular, reducing gender gaps in access to resources, leadership, and income can help diversify household diets. However, data on the impact of shortening the difference in working hours between wives and husbands for the benefit of food safety are yet to be conclusive. Additionally, gender gaps in the group of non-coresident mothers-in-law and non-migrants hurt household food security.

Conclusion

The paper also provides further justification for policies and interventions that aim to improve women's bargaining position in the household.

Production Choices and Food Security: A Review of Studies Based on a Micro-Diversity Perspective

Given the 'subsistence' character of smallholder production, agricultural production diversification is often seen as an effective strategy for smallholders to improve their diets' diversity and nutritional status, yet the existing evidence remains inadequate. The study applies bibliometric data from the "Web of Science" database to synthesize 46 papers from developing countries to explore the relationship between production diversity, dietary diversity, and nutrition in smallholder households. The study identifies the most influential journals, authors, organizations, and countries and reveals research themes related to agricultural production and food security. This data analysis can help researchers target potential collaborators and access influential literature in agricultural production diversity and dietary diversity research. In addition, the results showed that agricultural production diversity potentially influences households' dietary diversity, with mixed results: Agricultural production diversification is the primary way to improve food and nutritional security among smallholder families with low socio-economic status, inaccessible transportation, and poverty; market access and trade have more potential to improve dietary diversity among smallholder households with well-developed markets and higher income levels; the significant measures of agricultural production diversity include Crop Counts, FGPD, SI, and SWDI; the significant measures of dietary diversity include HDDS and IDDS. This paper provides a roadmap for agricultural production and food security researchers by conducting a systematic review of the literature, summarizing some research methods and perspectives applicable to local socio-economic development.

Fiscal policy, green finance, and low carbon transformation nexus: a novel study unleashing the synergistic effects of carbon reduction and pollution in China

Under the simultaneous demands of combating environmental pollution and decreased carbon emissions, it is critical to investigate the combined effect of agricultural contamination reduction and fiscal policy carbon reduction to support and promote green agriculture and low-carbon transformation. Based on provincial panel data of 2007 to 2020 in China, this paper employs the spatial Dubin model to empirically examine the pollution reduction and carbon reduction effects of fiscal policies supporting agriculture, as well as calculating the synergistic effect of pollution reduction and carbon reduction. Our study's findings reveal that non-point source agricultural pollution and agricultural carbon emissions have a tendency of growing and subsequently reducing, such as increasing from 2007 to 2015 and decreasing from 2016 to 2020. Second, results demonstrate that agricultural carbon emissions and agricultural pollution have a positive geographical dependency in each province, and fiscal policies supporting agriculture have high-high and low-low spatial clustering features. Furthermore, fiscal policies that promote agriculture can lower local agricultural carbon emissions and pollution while also having a considerable beneficial spillover impact on neighboring provinces. According to the study findings, the fiscal policy for supporting agriculture has a negative pollution reduction impact and a positive synergistic effect, resulting in a synergistic effect of agricultural pollution reduction and carbon reduction. The outcomes of this study can serve to promote carbon-reduction measures and provide recommendations for future policy development.

Forty Years after Poverty Reduction in China: The Role of Women's Empowerment in Enhancing Food Security and Diet Diversity

This study analyzed the role of women's empowerment in diversifying the diet of households through their own production. Developed from empowerment and food security theories, this study constructed measures from the household dietary diversity score (HDDS) and Women's Empowerment Index (WEI). The study focused on poverty-stricken regions in China and conducted a thematic questionnaire-based household survey on gender and food consumption in 2021. Based on micro-level evidence from 1199 rural households, this research found a low score of women's empowerment and an average WEI of 0.689; the status of diet diversity, measured by the HDDS, varied by income and social class; and the average rate was low. Agricultural production diversity and women's empowerment are positively associated with diet diversity. There is strong evidence that women's employment mitigates the side effects of decreasing production diversity on households' diet security. As a result, women's empowerment can potentially mitigate the adverse consequences of low agricultural diversification in household diet quality in less developed areas. This study provides evidence for repurposing food and agricultural policies toward healthy diets and gender-responsive agrifood systems.

The Income Elasticities of Food, Calories, and Nutrients in China: A Meta-Analysis

Estimating food- and nutrient-income elasticities is important for making food and nutrition policies to combat malnutrition. There are many studies that have estimated the relationship between income growth and food/nutrient demand in China, but the results are highly heterogeneous. We conducted a meta-analysis in China to systematically review the elasticity of food, calories, and other nutrients to income. We considered a meta-sample using a collection of 64 primary studies covering 1537 food-income elasticities, 153 nutrient-income elasticities, and 147 calorie-income elasticity estimates. There are significant differences in the size of the income elasticities across food and nutrient groups. We found that food- and calorie-income elasticity appear to decline as per capita income increases, except for vitamin and aquatic products. We also found a publication bias for food and calories, and in particular, the study attributes may be important, as they can influence estimates. Given the limited study on nutrient-income elasticity, understanding the impact of income changes on nutrient intake is an important direction worthy of further research.

[Advances on optic disc morphological features and peripapillary structure changes in high myopia]

High myopia is an important cause of low vision and blindness in the world, most of which are characterized by the prolongation of the axial length, accompanied by various degenerative changes of fundus posterior pole, especially in the optic disc area and peripapillary structures, such as optic disc tilt, optic cup and rim changes, chorioretinal atrophy, posterior staphyloma and intrachoroidal cavitation, and so on. This article reviews the optic disc morphological features and peripapillary structure changes of high myopia, in order to reveal the pathogenesis of high myopia and provide new ideas for finding more effective prevention and treatment methods.

Lipid accumulation product is a reliable indicator for identifying metabolic syndrome: the China Multi-Ethnic Cohort (CMEC) Study

BACKGROUND

Previous studies have shown that lipid accumulation product (LAP) was associated with the risk of cardiometabolic disease. It is not clear whether LAP could be used as a marker to identify metabolic syndrome (MetS) among Chinese ethnic groups.

AIM

To assess the reliability of LAP as a maker to identify MetS among Dong adults.

DESIGN

Population-based cross-sectional study.

METHOD

We included 6494 Dong individuals (1403 patients) aged 30-79 years from southwest China. MetS was established by Chinese Diabetes Society. Logistic regression model was utilized to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Receiver operating characteristic (ROC) curve was utilized to calculate area under the ROC curve (AUC) and 95% CIs to obtain the identification ability for MetS.

RESULTS

The risk of MetS was increased with per 5 units increase of LAP (OR 1.37 [95% CI, 1.34-1.39]). Similar results were found in subgroup analyses and sensitivity analyses. Clustered metabolic risk associated with per 5 units increase of LAP was observed for people with 1 (OR 1.59 [95% CI, 1.53-1.65]), 2 (2.15 [2.06-2.24]), 3 (2.59 [2.48-2.71]), 4 (2.81 [2.69-2.95]) and 5 (3.03 [2.87-3.21]) MetS components. LAP presented higher AUC (0.915 [95% CI, 0.907-0.923]) than other included obesity indices (P < 0.05).

CONCLUSION

These data support evidence that LAP was related to the risk of MetS, had a high AUC and could be a reliable index for identifying MetS patients among Dong adults in Chinese.

[Application of dual-channel contrast-enhanced ultrasound in classification of hilar cholangiocarcinoma and diagnosis of etiology of low biliary obstruction]

Objective: To investigate the clinical value of dual-channel contrast-enhanced ultrasound (DCUS) in the classification of hilar cholangiocarcinoma and the diagnosis of the etiology of low obstructive jaundice. Methods: The data of 114 patients with obstructive jaundice examined by the Department of Ultrasound of Lanzhou University Second Hospital from October 2018 to February 2020 were retrospectively collected. There were 60 males and 54 females, aged 37~84 (63±10) years. All patients underwent preoperative transvenous contrast-enhanced ultrasound (CEUS), intraoperative puncture needles, postoperative ultrasound-guided percutaneous transhepatic cholangiocarcinography (UG-PTC) and three-dimensional ultrasound cholangiography (3D-USC) through an external drainage tube, known as DCUS. The classification of hilar cholangiocarcinoma and the nature of low biliary tract obstruction were determined according to the characteristics of DCUS images. All patients who have received DCUS underwent magnetic resonance cholangiopancreatography (MRCP) and X-ray cholangiography. X-ray cholangiography was used as the gold standard for classification of hilar cholangiocarcinoma, and the accuracy of US, CEUS and DCUs was analyzed. Low obstructive jaundice was characterized by surgical pathology as the gold standard, and the diagnostic efficacy of conventional ultrasound (US), CEUS and DCUs was analyzed. At the same time, the receiver operating characteristic (ROC) curve was used to compare the efficacy of MRI+MRCP and DCUS in determination of the nature of low biliary obstruction. Results: The coincidence rates of US, CEUS, and DCUS in the classification of hilar cholangiocarcinoma and X-ray cholangiography were: 75.6% (34/45), 82.2% (37/45), and 93.3% (42/45), respectively. The coincidence rates of US, CEUS, and DCUS in the determination of the nature of low biliary obstruction and surgical pathology were 56.5% (39/69), 82.6% (57/69), and 85.5% (59/69), respectively. Compared with conventional ultrasound, CEUS had no statistically significant difference in the diagnosis of hilar cholangiocarcinoma (P=0.438), and DCUS had statistically significant difference in the diagnosis of hilar cholangiocarcinoma (P=0.039).ROC curve analysis suggested that the cut-off value of MRI+MRCP grade and DCUS grade for diagnosing benign and malignant low biliary obstruction were both 2.5; the area under the curve (AUC) were 0.897 and 0.906, respectively (both P<0.01); sensitivity were 77.5% and 93.1%, respectively; and the specificity were 87.5% and 82.8%, respectively. Conclusion: The value of DCUS in the classification of hilar cholangiocarcinoma and the qualitative diagnosis of low biliary tract obstruction was comparable to that of X-ray cholangiography and MRCP. DCUS had important clinical application value in the classification of hilar cholangiocarcinoma and the etiological diagnosis of low obstructive jaundice.

Fall armyworm invasion heightens pesticide expenditure among Chinese smallholder farmers

Invasive species are a prominent feature of global change. Aside from their direct impacts on biodiversity and ecosystem functioning, invasive crop pests routinely trigger environmentally-disruptive actions e.g., unguided applications of synthetic pesticides. Since 2016, the polyphagous fall armyworm (FAW, Spodoptera frugiperda J.E. Smith) has rapidly spread across Africa and Asia, impacting millions of hectares of agricultural crops. Upon its invasion of Yunnan (China) in late 2018, S. frugiperda attained outbreak population levels and inflicted important feeding damage in smallholder-managed maize crops. In this study, we show how local maize growers rely primarily on pesticides for FAW management and employ these products at 3-fold higher application frequencies as compared to 2018. Local reliance upon high-risk compounds (i.e., pyrethroids, organophosphates) decreased over time, with a respective 100% and 62% farmers using these compounds in 2018 versus 27% and 5% in 2020. Conversely, 71% and 95% farmers used new, selective compounds such as emamectin benzoate and chlorfenapyr by 2020. The full cost of pesticide-based crop protection increased from US $81 per hectare and season in 2018 to $276 in 2020. In farmer-managed fields, FAW infestation levels averaged 8.3 larvae per 100 plants and thus remained below economic injury levels (EILs) as established in other countries. Farmers' use of two or more pesticide sprays per season likely was not economically justified. Our work demonstrates how the FAW invasion has altered pest management regimes in Yunnan's maize crop, deepening farmers' pesticide dependency, and potentially exacerbating its burden on household budgets. Sustainable pest management schemes urgently need to be devised for smallholder maize systems in China and across the FAW invaded range.

Socioeconomic and Geographic Pattern of Food Consumption and Dietary Diversity among Children Aged 6-23 Months Old in Ghana

Dietary inadequacy is a major challenge among young children in Ghana. Nutritional policies are required for optimum child nutrition and development. This study explored food consumption and dietary diversity by socioeconomic status and geographical location among children aged 6–23 months in Ghana. We used the latest national representative, cross-sectional data from the Ghana Demographic and Health Survey (GDHS-2014). A total of 887 children aged 6–23 months were used in the final analysis. The survey collected data on children’s food consumption through their mothers in the 24 h recall method. Multiple logistic regression models were used to assess the relationship between socioeconomic status and geographical location with food consumption and adequate dietary diversity after adjusting for control variables. The study revealed an association between specific food item consumption, food groups, and dietary diversity by socioeconomic and geographic characteristics. However, dairy consumption increased faster than other nutritional foods when socioeconomic status increased. Furthermore, the study revealed that children’s chances of consuming particular food items and food groups differed across Ghana’s 10 regions. The average probabilities of consuming adequate dietary diversity between the Greater Accra region and Ashanti region were 43% vs. 8% (p < 0.001). Consumption of grains, root, and tubers were relatively higher but low for Vitamin A-rich fruits and vegetables and legumes and nuts for children aged 6–23 months in Ghana. Overall, the mean dietary diversity score was low (3.39; 95% CI: 3.30–3.49) out of eight food groups, and the prevalence of adequate dietary diversity was 22% only. There is a need for policy interventions to ensure appropriate dietary practices to promote healthy growth of children.

Social-Psychological Factors in Food Consumption of Rural Residents: The Role of Perceived Need and Habit within the Theory of Planned Behavior

To address the problem of malnutrition in poor rural areas of China, this study aims to examine the effects of social-psychological factors in food consumption of rural residents in poor counties of Southwest China. In addition, it investigates the role of perceived need and habit within the theory of planned behavior (TPB) in predicting food consumption. A survey with random sampling was conducted on rural residents (n = 424), and the theoretical frameworks of both the standard and extended TPB were applied for comparison purposes. Structural equation modeling was applied to test the relationships among constructs. Consumption of five food items was studied, respectively: meat, eggs, dairy, fish, and fruits. Results showed that incorporation of perceived need and habit substantially increased the explanatory power of the TPB, but these factors only had significant direct effects on intention rather than behavior. Perceived need and habit are stronger predictors of intention than any other TPB construct for consumption of all food items except for meat. We found indirect effects of the constructs in the extended TPB model on consumption to be different across food items. Practical implications to improve consumption of different food items were proposed accordingly.

MicroRNA expression profiling identifies miR-328 regulates cancer stem cell-like SP cells in colorectal cancer

Background:

Side population (SP) cells and their relationship to stem cell-like properties have been insufficiently studied in colorectal cancer (CRC). MicroRNAs (miRNAs) have attracted much attention but their roles in the maintenance of SP phenotype remain unclear.

Methods:

The SPs from CRC cell lines and primary cell cultures were analysed for stem cell-like properties. MiRNA microarray analysis identified miR-328 as a potential stemness miRNA of SP phenotype. The level of miR-328 expression in clinical samples and its correlation with SP fraction were determined. Gain-of-function and loss-of-function studies were performed to examine its roles in cancer stem-like SP cells. Furthermore, bioinformatics prediction and experimental validation were used to identify miR-328 target genes.

Results:

The SP cells sorted from CRC possess cancer stem cell (CSC)-like properties, including self-renewal, differentiation, resistance to chemotherapy, invasive and strong tumour formation ability. MiR-328 expression was significantly reduced in SP cells compared with Non-SP cells (P<0.05). Moreover, miR-328 expression was downregulated in CRC (n=33, P<0.05) and low miR-328 expression tend to correlate with high SP fraction (n=15, r=0.6559, P<0.05, Pearson's correlation). Functional studies indicated that miR-328 expression affects the number of SP cells. In addition, miR-328 overexpression reversed drug resistance and inhibited cell invasion of SP cells. Furthermore, luciferase reporter assay demonstrated that miR-328 directly targets ABCG2 and MMP16 and affects the levels of mRNA and protein expression in SP cells.

Conclusion:

These findings indicate that CRC contain cancer stem-like SP cells. MiR-328 has an important role in maintaining cancer stem-like SP phenotype that may be a potential target for effective CRC therapy.

Effects of Rapamycin on Breast Cancer Cell Migration through the Cross-Talk of MAPK Pathway

Phase I/II clinical studies with rapamycin analogs in breast and other cancers have demonstrated favorable responses. However, little is known on the effects of the mTOR inhibitor on breast cancer cell metastasis, which is a major cause of morbidity and death. We developed a highly sensitive 3-dimensional (3D) proliferation/invasion assay using quantitative bioluminescence (BL) imaging and applied this assay to evaluate the effects of rapamycin on the triple negative breast cancer cell line MDA-MB231. Without cytotoxicity of rapamycin on this cell line, rapamycin at 10nM inhibited the cell migration/invasion, but not at 1nM and 100nM, which was confirmed by the time-lapse single cell tracking analysis. The quantification of cytoskeleton changes showed most potent effects of 10nM rapamycin on the MDA-MB231 cells, with the formation and rearrangement of specialized cell membrane structures and actin fiber implicated in cell motility. Then, the Panorama Cell Signaling Antibody Microarray, enabling the global comparative analysis of cell signal proteins simultaneously, was exploited to analyze the effects of rapamycin on the cellular signaling network of the MDA-MB231 breast cancer cell line. 100nM rapamycin activated the MAPK pathway obviously, through the attenuated negative feedback of activated S6K1 to PI3K-Raf, which increased the expressions of activated Jun N-terminus kinase (JNK), Erk1/2, MEK-1, Raf-pS621, and MAPK-activated protein kinase 2 (MAPKAPK2) in the cells exposed to 100nM rapamycin. MEK inhibitor U0126 or PD98059 could restore the anti-migration effects of 100nM rapamycin on the MDA-MB231 cells. Furthermore, the combination of MEK inhibitors and rapamycin performed synergism on inhibiting the cell proliferation and migration/invasion. Accordingly, rapamycin at a certain dose suppresses MDA-MB231 cell migration/invasion, and the co-targeting of mTOR and MAPK pathways enhances the inhibition on cell proliferation and migration/invasion, underscoring the potential therapeutic utility of rapamycin, and rapamycin combining with MAPK inhibitors in triple negative breast cancer progression, and the results highlight the cross-talk homeostasis of mTOR and MAPK pathways in cancer treatment.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5080.

[Morphological and microscopic identification of herba artemisiae scopariae and its adulterants]

Pharmacognostical studies of Herba Artemisiae Scopariae and its adulterants were compared on morphological and microscopic characteristics. The detailed characteristics of powder microscopic identification were described.

Human nuclear respiratory factor 2 alpha subunit cDNA: isolation, subcloning, sequencing, and in situ hybridization of transcripts in normal and monocularly deprived macaque visual system

Nuclear respiratory factor 2 (NRF-2) has been shown to contribute to the transcriptional regulation of a number of subunits of respiratory chain enzymes, including cytochrome c oxidase (CO). Our recent study demonstrated a parallel distribution of the alpha subunit proteins of NRF-2 (NRF-2 alpha) with CO in the monkey striate cortex, and that it can be regulated by neuronal activity. To determine whether this regulation is at the transcriptional level, the present study examined the expression of NRF-2 alpha mRNA in normal and monocularly deprived adult monkeys. A partial NRF-2 alpha cDNA was isolated from a human brain cDNA library. Sequence analysis revealed that it shared 99% identity with the published sequence from human HeLa cells. Riboprobes of NRF-2 alpha was generated and labeled with digoxigenin-11-UTP for in situ hybridization. The expression pattern of NRF-2 alpha mRNA in the normal striate cortex paralleled that of CO activity. It was highly expressed in layers IVC and VI, which contained high levels of CO, and more densely expressed in puffs of layers II and III than in interpuffs. In monkeys monocularly treated with tetrodotoxin for 1 day to 2 weeks, both NRF-2 alpha expression and CO activity were reduced in deprived ocular dominance columns of the visual cortex and in deprived layers of the lateral geniculate nucleus. These data indicate that, in the normal and visually deprived adult monkeys, NRF-2 alpha is regulated by neuronal activity at the transcriptional level.

Nuclear respiratory factor-2 subunit protein: correlation with cytochrome oxydase and regulation by functional activity in the monkey primary visual cortex

Previous studies have shown that a transcription factor of the Ets family, nuclear respiratory factor 2 (NRF-2), can activate in vitro the gene expression of cytochrome oxidase (CO), a mitochondrial enzyme of oxidative metabolism. The goals of our present study were to determine whether the distribution of NRF-2 alpha subunit proteins correlated with that of CO activity in the macaque monkey visual cortex and whether the level could be perturbed by visual deprivation. We generated polyclonal antibodies specifically against human NRF-2 alpha subunit. In normal monkeys, patterns of NRF-2 alpha distribution resembled closely that of CO activity: 1) NRF-2 alpha immunoreactivity was localized in both nuclei and cytoplasm of neurons, but the levels differed among various laminae; 2) layers IVA, IVC, and VI, which had high CO activity, were labeled more densely by NRF-2 alpha than layers I, IVB, and V, which contained lower levels of both NRF-2 alpha and CO activity; and 3) CO-rich puffs in layers II and III contained a higher level of NRF-2 alpha than CO-poor interpuffs. From 1 day to 7 days after monocular impulse blockade with tetrodotoxin, there was a progressive reduction of NRF-2 alpha in deprived ocular dominance columns, in parallel with decreases in CO activity. These results suggest that local levels of NRF-2 in the monkey visual cortex closely reflect neuronal physiological and metabolic levels revealed by CO activity and that the expression of NRF-2 alpha, like that of CO, is regulated tightly by neural functional activity.

Neurochemical organization of the macaque retina: effect of TTX on levels and gene expression of cytochrome oxidase and nitric oxide synthase and on the immunoreactivity of Na+ K+ ATPase and NMDA receptor subunit I

The present study examined the relationship between an important energy-generating enzyme (cytochrome oxidase; CO), a key energy-consuming enzyme (Na+ K+ ATPase) and neurochemicals associated with excitatory glutamatergic synapses (NMDAR1 and neuronal nitric oxide synthase, nNOS) in the adult macaque retina. Polyclonal antibodies against neuronal nitric oxide synthase and N-methyl-D-aspartate receptor subunit I were generated for immunohistochemical examination and labeled sites not previously reported were found. We have also isolated cDNAs for cytochrome oxidase subunits III (mitochondrial-encoded) and IV (nuclear-encoded), as well as for a fragment of neuronal nitric oxide synthase, from a human cDNA library. The distributions of mRNAs of these genes were analyzed by in situ hybridization. We found that three or more of the markers examined coexisted in a number of sites: (a) In the inner segments of photoreceptors, high energy demand for maintaining the dark current was placed by Na+ K+ ATPase. This was partially met by ATP-generating enzymes such as CO. Neuronal NOS was also present there for the synthesis of NO and the cascading event leading to the generation of cGMP and the gating of channels for visual transduction. (b) Both the outer and inner plexiform layers had detectable amounts of all four markers, although the levels varied among them. This was most likely due to the presence of depolarizing glutamatergic synapses arising from photoreceptors and bipolar cells and such synaptic events were energy-demanding. The involvement of NMDA receptors and nNOS in these synaptic layers is strongly implicated in the present study. (c) All four markers were present in the majority of retinal ganglion cells, with some inherent heterogeneity related to intensity and size. Retinal ganglion cells are known to receive excitatory synapses from glutamatergic bipolar cells and are themselves highly active. The presence of both NMDAR1 and nNOS in these cells were verified in the present study and the energy demands related to these synaptic activities were necessarily high. Thus, active ion transporting functions related to synaptic or non-synaptically induced repolarization from the basis for an interrelationship between the neurochemicals/enzymes studied. Finally, (d) all four markers and the gene expression of CO and nNOS in the macaque retina were regulated by neuronal activity.

Mitochondrial- and nuclear-encoded subunits of cytochrome oxidase in neurons: differences in compartmental distribution, correlation with enzyme activity, and regulation by neuronal activity

Cytochrome oxidase (CO), a mitochondrial energy-generating enzyme, contains both mitochondrial- and nuclear-encoded subunits. In neurons, local levels of CO activity vary among different neuronal compartments, reflecting local demands for energy. The goals of the present study were to determine if compartmental distribution of CO subunit proteins from the two genomes was correlated with local CO activity, and if their expression was regulated proportionately in neurons. The subcellular distributions of mitochondrial-encoded CO III and nuclear-encoded CO Vb proteins were quantitatively analyzed in mouse cerebellar sections subjected to postembedding immunocytochemistry. Local levels of subunit proteins were also compared to local CO activity, as revealed by CO cytochemistry. In order to study the regulation of subunit protein expression, we assessed changes in immunoreactivity of the two CO subunits as well as changes in CO activity in mouse superior colliculus after 1 to 7 days of monocular enucleation. We found that immunoreaction product for both CO III and CO Vb existed almost exclusively in mitochondria, but their compartmental distributions were different. CO III was nonhomogeneously distributed among different neuronal compartments, where its local level was positively correlated with that of CO activity. In contrast, the subcellular distribution of CO Vb was relatively uniform and did not bear a direct relationship with that of CO activity. Moreover, the two subunit proteins were disproportionately regulated by neuronal activity. CO III and CO activity exhibited parallel decreases after the deprivation of afferent input, and their changes were earlier and to a greater degree than that of CO Vb proteins. Thus, the present findings indicate that the local expression and/or distribution of CO subunit proteins from the two genomes may involve different regulatory mechanisms in neurons. Our data also suggest that the activity-dependent regulation of mitochondrial-encoded CO subunits is likely to play a major role in controlling the local levels of CO content and its activity.

Metabolic and neurochemical plasticity of gamma-aminobutyric acid-immunoreactive neurons in the adult macaque striate cortex following monocular impulse blockade: quantitative electron microscopic analysis

The purpose of the present study was to examine the effects of retinal impulse blockade on gamma-aminobutyric acid (GABA)-immunoreactive (GABA-IR) neurons in cytochrome oxidase (CO)-rich puffs of the adult monkey striate cortex. Specifically, we wished to know if changes occurred in their CO activity, GABA immunoreactivity, and synaptic organization. A double-labeling technique, which combined CO histochemistry and postembedding GABA immunocytochemistry on the same ultrathin sections, was used to reveal simultaneously the distribution of the two markers. We quantitatively compared changes in GABA-IR neurons of deprived puffs (DPs) with respect to non-deprived puffs (NPs) 2 weeks after monocular tetrodotoxin treatment. We found that the proportion of darkly CO reactive mitochondria in GABA-IR neurons of DPs drastically decreased to about half of those in NPs. There was a greater reduction of CO levels in GABA-IR axon terminals than in their cell bodies and dendrites. In contrast, most non-GABA-IR neurons displayed no significant change in their CO levels. Morphologically, GABA-IR neurons and axon terminals in DPs showed a significant shrinkage in their mean size. GABA immunoreactivity, as indicated by the density of immunogold particles in GABA-IR neurons, declined in DPs, and a greater decrease was also found in axon terminals than in cell bodies or dendrites. Moreover, the numerical density of GABA-IR axon terminals and synapses in DPs was significantly reduced without changes in that of asymmetric and symmetric synapses. Thus, the present results support the following conclusions: 1) Oxidative metabolism and neurotransmitter expression in GABA-IR neurons are tightly regulated by neuronal activity in adult monkey striate cortex; 2) GABA-IR neurons are much more vulnerable to functional deprivation than non-GABA-IR ones, suggesting that these inhibitory neurons have stringent requirement for sustained excitatory input to maintain their heightened oxidative capacity; and 3) intracortical inhibition mediated by GABA transmission following afferent deprivation may be decreased in deprived puffs, because the oxidative capacity and transmitter level in GABAergic neurons, especially in their axon terminals, are dramatically reduced.

Differential glutamatergic innervation in cytochrome oxidase-rich and -poor regions of the macaque striate cortex: quantitative EM analysis of neurons and neuropil

One of the hallmarks of the primate striate cortex is the presence of cytochrome oxidase (CO)-rich puffs and CO-poor interpuffs in its supragranular layers. However, the neurochemical basis for their differences in metabolic activity and physiological properties is not well understood. The goals of the present study were to determine whether CO levels in postsynaptic neuronal compartments were correlated with the proportion of excitatory glutamate-immunoreactive (Glu-IR) synapses they received and if Glu-IR terminals and synapses in puffs differed from those in interpuffs. By combining CO histochemistry and postembedding Glu immunocytochemistry on the same ultrathin sections, the simultaneous distribution of the two markers in individual neuronal profiles was quantitatively analyzed. As a comparison, adjacent sections were identically processed for the double labeling of CO and GABA, an inhibitory neurotransmitter. In both puffs and interpuffs, most axon terminals forming asymmetric synapses (84%)--but not symmetric ones, which were GABA-IR--were intensely immunoreactive for Glu. GABA-IR neurons received mainly Glu-IR synapses on their cell bodies, and they had three times as many mitochondria darkly reactive for CO than Glu-rich neurons, which received only GABA-IR axosomatic synapses. In puffs, GABA-IR neurons received a significantly higher ratio of Glu-IR to GABA-IR axosomatic synapses and contained about twice as many darkly CO-reactive mitochondria than those in interpuffs. There were significantly more Glu-IR synapses and a higher ratio of Glu- to GABA-IR synapses in the neuropil of puffs than of interpuffs. Moreover, Glu-IR axon terminals in puffs contained approximately three times more darkly CO-reactive mitochondria than those in interpuffs, suggesting that the former may be synaptically more active. Thus, the present results are consistent with our hypothesis that the levels of oxidative metabolism in postsynaptic neurons and neuropil are positively correlated with the proportion of excitatory synapses they receive. Our findings also suggest that excitatory synaptic activity may be more prominent in puffs than in interpuffs, and that the neurochemical and synaptic differences may constitute one of the bases for physiological and functional diversities between the two regions.

Double labeling of GABA and cytochrome oxidase in the macaque visual cortex: quantitative EM analysis

In the primate striate cortex, cytochrome oxidase (CO)-rich puffs differ from CO-poor interpuffs in their metabolic levels and physiological properties. The neurochemical basis for their metabolic and physiological differences is not well understood. The goal of the present study was to examine the relationship between the distribution of gamma aminobutyric acid (GABA)/non-GABA synapses and CO levels in postsynaptic neuronal profiles and to determine whether or not a difference existed between puffs and interpuffs. By combining CO histochemistry and postembedding GABA immunocytochemistry on the same ultrathin sections, the simultaneous distribution of the two markers in individual neuronal profiles was quantitatively analyzed. In both puffs and interpuffs, GABA-immunoreactive (GABA-IR) neurons were the only cell type that received both non-GABA-IR (presumed excitatory) and GABA-IR (presumed inhibitory) axosomatic synapses, and they had three times as many mitochondria darkly reactive for CO than non-GABA-IR neurons, which received only GABA-IR axosomatic synapses. GABA-IR neurons and terminals in puffs had a larger mean size, about twice as many darkly reactive mitochondria, and a higher ratio of non-GABA-IR to GABA-IR axosomatic synapses than those in interpuffs (2.3:1 vs. 1.6:1; P < 0.01). There were significantly more synapses of both non-GABA-IR and GABA-IR types in the neuropil of puffs than of interpuffs; however, the ratio of non-GABA-IR to GABA-IR synapses was significantly higher in puffs (2.86:1) than in interpuffs (2.08:1; P < 0.01). Our results are consistent with the hypothesis that the level of oxidative metabolism in postsynaptic neurons and neuronal processes is tightly governed by the strength and proportion of excitatory over inhibitory synapses. Thus, the present results suggest that (1) GABA-IR neurons in the macaque striate cortex have a higher level of oxidative metabolism than non-GABA ones because their somata receive direct excitatory synapses and their terminals are more tonically active; (2) the higher proportion of presumed excitatory synapses in puffs imposes a greater energy demand there than in interpuffs; and (3) excitatory synaptic activity may be more prominent in puffs than in interpuffs because puffs receive a greater proportion of excitatory synapses from multiple sources including the lateral geniculate nucleus, which is not known to project to the interpuffs.