Visual activity in areas V3a and V3 during reversible inactivation of area V1 in the macaque monkey.

1. Behavioral studies in the monkey and clinical studies in humans show that some visuomotor functions are spared in case of a V1 lesion. This residual vision appears to be subserved at least partially by visual activity in extrastriate cortex. Earlier studies have demonstrated that neurons in area V2 lose their visual responses when V1 is reversibly inactivated. On the other hand, Rodman and collaborators have recently shown that neurons in the middle temporal area (area MT) remain visually responsive when V1 is lesioned or inactivated. The purpose of the present study was to determine whether area MT is unique among extrastriate cortical areas in containing visually responsive neurons in the absence of input from area 17. 2. A circular part of the opercular region of area V1 was reversibly inactivated by cooling with a Peltier device. In that condition, 149 sites were recorded in the retinotopically corresponding regions of areas V3 and V3a. 3. About 30% of sites in area V3a still responded to visual stimulation when V1 was inactivated. On the contrary, nearly all sites in area V3 ceased to fire to visual stimulation. Receptive-field properties were assessed with qualitative measures; for most single cells or multiunit sites that responded during V1 inactivation, these properties did not change during cooling. 4. These results suggest that area V3a could take part in spared visuomotor abilities in case of a lesion of V1. Areas V3a and MT are both part of the occipitoparietal pathway, which suggests that the residual vision observed after a lesion of area 17 may depend mostly on this pathway.     

Seroprevalence of Zika Virus in Amphawa District,Thailand, after the 2016 Pandemic

In 2016, Zika virus (ZIKV) infection was declared a public health emergency of international concern because of the neurological consequences in babies born to infected people. Because of the mild and nonspecific symptoms, serological tests are essential in epidemiological studies. However, cross-reactive antibodies between other Flaviviridae members may complicate the interpretation of results of these tests. This study investigated the seroprevalence of ZIKV infection in Samut Songkhram in central Thailand which was affected by the Zika outbreak of 2016. Three hundred and fifty volunteers aged 5–50 years in Amphawa District, Samut Songkhram, were enrolled between April 2017 and April 2018. ZIKV nonstructural protein 1 (NS1) immunoglobulin G enzyme-linked immunosorbent assay (ELISA) was used to screen serum samples collected on the first day of enrollment and after 6 and 12 months. The seroprevalence and seroconversion of ZIKV were assessed. Cases of ZIKV seroconversion were verified as evidence of ZIKV infection by NS1 blockade-of-binding ELISA and plaque reduction neutralization test (PRNT50). ZIKV seroprevalence in Amphawa was 15.1–17.8% with no significant change over the year. The total seroconversion rate throughout the year was 7/100 person-years. The ratio of asymptomatic to symptomatic infections was 4.5:1. The cases in our study confirmed the occurrence of occult ZIKV infections in the community. These undetected infections might promote the spread of ZIKV in vulnerable groups of the community.     

Distribution of Striatin,a newly identified calmodulin-binding protein in the rat brain: An in situ hybridization and immunocytochemical study

Striatin, a 110-kDa protein, is the first member of the tryptophane-aspartate repeat protein family known to bind calmodulin in the presence of Ca²⁺. We examined the distribution of striatin and its mRNA in the rat central nervous system (CNS) by using immunocytochemistry and in situ hybridization, respectively. Striatin immunostaining and mRNA labeling patterns are generally concordant. Regions showing the most intense staining are the dorsal striatum, nucleus accumbens (anterior and shell parts), olfactory tubercle, red nucleus, subthalamic nucleus, cranial nerve motor nuclei, and layer IX of the spinal cord (motoneurons). Low levels of both striatin and its mRNA are detected in the cerebral cortex, thalamus, septum, amygdala, hippocampus, midbrain and cerebellum. Striatin-immunoreactive neuronal processes are found predominantly in the structures containing striatin-positive neurons, suggesting that these labeled processes represent dendritic arborization rather than axonal processes. Except for the medial forebrain bundle, all axonal fiber tracts examined are devoid of striatin immunolabeling. These data show that the somatodendritic localization of striatin, previously described in the striatum, may be a main feature of the subcellular distribution of this protein throughout the CNS. Although widely distributed in neurons throughout the rat CNS, striatin is expressed prominently in the structures belonging to the motor system, suggesting that this protein may play a preponderant role in motor control. J. Comp. Neurol. 397:41–59, 1998. © 1998 Wiley-Liss, Inc.     

Childhood immunization in rural Malawi: time of administration and predictors of non-compliance

A cohort of 760 newborns was followed prospectively for 2 years to ascertain the time of administration of childhood vaccinations in rural Malawi and to study predictors of non-compliance with national vaccination recommendations. At 1 year of age, 99% of the infants were fully vaccinated against tuberculosis, 91% against polio, 90% against diphtheria, pertussis and tetanus and 64% against measles. At 2 years, the corresponding vaccination coverages were 99%, 93%, 93% and 84%. On average, all vaccinations were given 1-3 months later than recommended. Many of the delayed measles vaccinations were given during a separate vertical campaign, during which 25% of previously unvaccinated 21-23-month-old children were identified and immunized. Non-compliance with vaccination recommendations was associated with living in villages with no access to mobile vaccination teams, birth between April and June and birth at home. In this rural Malawian area, most vaccination services were functioning well. To increase measles vaccination coverage, regular outreach activities should be encouraged.     

Intralaminar thalamic nuclei lesions: widespread impact on dopamine denervation-mediated cellular defects in the rat basal ganglia

Intralaminar thalamic nuclei represent a major site of non-dopaminergic degeneration in Parkinson disease, but the impact of this degeneration on the pathophysiological functioning of basal ganglia remains unknown. To address this issue, we compared the effects of 6-hydroxydopamine-induced lesions of nigral dopamine neurons alone or combined with ibotenate-induced lesions of intralaminar thalamic neurons on markers of neuronal metabolic activity in the rat basal ganglia using in situ hybridization histochemistry. Thalamic lesions prevented most of the dopamine denervation-induced changes (i.e. the increases in mRNA levels of enkephalin and GAD67 in the striatum, of GAD67 in the globus pallidus and entopeduncular nucleus, and of cytochrome oxidase subunit-I in the subthalamic nucleus), but did not affect the downregulation of striatal substance P and upregulation of GAD67 in the substantia nigra pars reticulata. We also provide immunohistochemical evidence that thalamic lesions markedly decreased striatal expression of the vesicular glutamate transporter vGluT2, confirming the association of this transporter with the thalamic projections to the basal ganglia. Altogether, these data reveal a major antagonistic influence of thalamic and dopaminergic afferents onto the basal ganglia and suggest that degeneration of thalamic neurons in Parkinson disease may represent an important factor counteracting expression of the defects associated with the dopamine denervation.     

Visuotopic organization of corticocortical connections in the visual system of the cat.

It has recently been demonstrated that, in contrast with the retinogeniculocortical projection, the corticocortical connections in the cat present a high degree of convergence and divergence. This suggests that some corticocortical connections link nonvisuotopically corresponding regions. Using fine-grain electrophysiological mapping and anatomical tracing, we have set out to test this possibility by placing a small injection of retrograde tracer in area 17 and by comparing the extent of visual field encoded in the region of area 18 containing labeled cells and that represented in the uptake zone. The results demonstrate that the size of the labeled region on the surface of area 18 is independent of eccentricity and that, despite its anisotrophy, this region of labeling encodes a broadly circular region of visual field that is larger than that encoded in the uptake zone of the tracer in area 17. For example, in the representation of lower visual field, a virtual point in area 17 that encodes a visual field region 4 degrees in diameter receives afferents from a region of area 18 encoding a region 11 degrees wide. Examination of the density of labeled cells in the labeled zone in area 18 reveals that the highest density is observed in a region in visuotopic correspondence with the injection site. However, high labeling density is also occasionally found in patches that do not represent the same visual field region as the injection site. Many receptive fields of neurons recorded in the labeled zone in area 18 only partially overlap or fail to overlap the visual field region encoded by the injection site. The results also demonstrate that the extent of visual field encoded in the labeled zone in area 18 is the same as that represented in the region of intrinsic labeling in area 17. It is suggested that cortical afferents coming from several cortical areas and converging on a column of cells in area 17 cover the same extent of visual field and that this cortical network constitutes the structural basis for the modulatory regions of the receptive field as well as the synchronization of neurons in different cortical areas.     

Ear length and kidney function decline after kidney donation

The preservation of kidney function after kidney donation depends on the kidney reserve – the potential of the remaining kidney to boost their function after loss of the other kidney. In Traditional Chinese Medicine, size and shape of the external ears are examined to evaluate the person's kidney health. We hypothesized that ear size might be a practical yet overlooked marker of kidney reserve. Fifty kidney transplantation donors were participated in this study. The length and width of both ears of all participants were measured during one of the post‐donation visits. Pre‐donation serum creatinine and post‐donation serum creatinine as well as other relevant parameters (age, sex, weight, height, etc.) of the participants were extracted from medical records. The estimated GFR was calculated from serum creatinine, age and sex using the CKD‐EPI equation. Ear length negatively associated with %GFR decline after kidney donation. For every 1 cm increase in ear length, it was associated with 5.7% less GFR decline after kidney donation (95% Confidence Interval 0.2 to 11.3, P = 0.04). Ear width, as well as age, sex, body weight, height, body mass index, and pre‐donation eGFR did not significantly associate with the GFR decline. Our findings support the notion of Traditional Chinese Medicine that ear morphology may be associated with kidney health and suggest that ear length might be a useful predictor of kidney function decline after kidney donation.     

Free radicals and inflammation. Protection of phagocytosine leukocytes by superoxide dismutase.

Isolated human polymorphonuclear leukocytes engaged in phagocytosis liberate superoxide radical and hydrogen peroxide into the surrounding medium. These two chemical species react to produce the hydroxyl radical, which attacks the leukocyte and leads to premature death of the cell. The hydroxyl radical may be scavenged by mannitol, or its formation can be prevented by the addition of superoxide dismutase or catalase to the medium, thereby eliminating the premature death of the cells. This phenomenon may partially explain the observed anti-inflammatory activity of superoxide dismutase.