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Depth of olfactory sulcus and olfactory function.

The aim of this study was to identify whether the depth of the olfactory sulcus relates to olfactory function in healthy subjects. Forty-four healthy, male volunteers (age range 22-45 years, mean age 28.3 years) were included in this study. Olfactory function was measured for phenyl ethyl alcohol odor thresholds, odor discrimination, and odor identification. Magnetic resonance imaging of the olfactory sulcus was performed immediately following olfactometry. Based on previous investigations the depth of the olfactory sulcus was measured in the plane of the posterior tangent through the eyeballs. Olfactory function correlated significantly with left-sided depth of the olfactory sulcus (r(44)=0.33, P=0.03); no such correlation was seen for the right side. In addition, olfactory sulcus depth was found to be significantly deeper on the right compared to the left side (t=5.61, P<0.001). The present results suggest that there is small, but significant relation between morphological brain structures and measures of olfactory function. Further, lateralization of olfactory sulcus depth may correlate to functional lateralization in the olfactory system. Thus, it may be carefully speculated that sensory input in the olfactory system results in cortical growth in the area of the olfactory sulcus, at least at some developmental stage.

Adult↗

Cortical language lateralization in right handed normal subjects using functional magnetic resonance imaging.

In 95% of right handed individuals the left hemisphere is dominant for speech and language function. The evidence for this is accumulated primarily from clinical populations. We investigated cortical topography of language function and lateralization in a sample of the right handed population using functional magnetic resonance imaging and two lexical-semantic paradigms. Activated cortical language networks were assessed topographically and quantitatively by using a lateralization index. As a group, we observed left hemispheric language dominance. Individually, the lateralization index varied continuously from left hemisphere dominant to bilateral representation. In males, language primarily lateralized to left, and in females, approximately half had left lateralization and the other half had bilateral representation. Our data indicate that a previous view of female bilateral hemispheric dominance for language (McGlone, 1980. Sex differences in human brain asymmetry: a critical survey. Behav Brain Sci 3:215-263; Shaywitz et al., 1995. Sex differences in the functional organization of the brain for language. Nature 373:607-609) simplifies the complexity of cortical language distribution in this population. Analysis of the distribution of the lateralization index in our study allowed us to make this difference in females apparent.

Adult↗

Endocrine function in amyotrophic lateral sclerosis. A review.

Endocrine and metabolic disturbances found in patients with ALS are reviewed. Pancreatic function, carbohydrate tolerance, calcium metabolism, testicular and ovarian thyroid and pituitary function are discussed. It is difficult to interpret these various metabolic dysfunctions as being either an epiphenomenon of ALS or possibly a clue to etiology of the disease. The data are reviewed and interpreted with these constraints.

Amyotrophic Lateral Sclerosis↗

Onset of neural function in the lateral line.

The development of the nervous system includes the formation of specific neuronal connections. Some insight into the mechanisms by which these connections are made may be obtained by determining the order in which the elements of a developing system begin to function and examining any changes that may occur in the system shortly after it begins functioning. I have investigated the lateral line of the South African clawed frog, Xenopus laevis and I have classified the afferent system into three elements. First, the transduction mechanism, which includes all components that couple the water vibrations to the release of transmitter from the hair cell. Second, the afferent synapse, at which there is transmitter release and subsequent postsynaptic conductance changes. And third, the afferent axon. I report here experiments suggesting that these elements become functional in the following order: first, the axon can conduct action potentials; second, transmission is established; third, the transduction mechanism can modulate transmitter release. This same sequence has been reported in a system related to the lateral line, the auditory pathway of mammals.

Afferent Pathways↗

Developmental instability and schizotypy.

INTRODUCTION: It has been suggested that evidence of developmental disturbance of cognition and lateralisation in schizophrenia can be best understood from the perspective of developmental stability (DS), an indicator of the extent to which an individual develops according to a specified ontogenic programme in the presence of environmental noise. Higher levels of fluctuating asymmetry (FA; the difference between right and left side of a quantitative morphological trait such as dermatoglyphics) are thought to reflect less DS. We examined this issue for dimensions of schizotypy. METHODS: Associations between FA, measures of laterality and cognitive function on the one hand, and negative and positive dimensions of schizotypy on the other, were examined in a sample of 260 healthy adolescents aged 11.9-15.6years. FA was measured as a-b ridge count right-left differences. Neuropsychological measures yielded a general cognitive ability score and a frontal function score. Laterality was assessed with the Annett scale. RESULTS: Measures of psychosis proneness were normally distributed. Negative schizotypy was associated with more FA and lower general cognitive ability in a dose-response fashion. The association with FA was more apparent in boys. No associations existed with laterality or frontal function. CONCLUSION: The negative dimension of schizotypy may be associated with early developmental instability, resembling the pattern seen in the negative symptom dimension of schizophrenia. Measures of fluctuating asymmetry may be more sensitive with regard to the schizotypy phenotype than measures of laterality.

Adolescent↗

Normal thyroid function in 32 patients with amyotrophic lateral sclerosis.

Thyroid function tests were evaluated in 32 patients with amyotrophic lateral sclerosis (ALS) with radioimmunoassay of triiodothyronine, thyroxine, thyroid-stimulating hormone, and free thyroxine. The presence of antithyroid antibody activities were also tested. All patients were found to have normal thyroid values except one, who had low triiodothyronine and all patients had negative for antithyroid antibody activities. The data suggest that ALS could not be related to a thyroid disorder.

Adult↗

[Evaluation of ventilatory functions in amyotrophic lateral sclerosis].

As the clinical signs of amyotrophic of lateral sclerosis (ALS) are late and not specific, spirometric measurements, study of respiratory strength muscles and analysis of night respiratory parameters are used to evaluate ventilatory functions. The prognostic value of vital capacity is well established, but with a poor sensitivity to detect the initial form of ALS. Gazometric parameters remain normal for a long time. Hypercapnia is late and due to a major reduction in the force of the inspiratory muscles. Level of diurnal venous bicarbonate could detect nighttime hypoventilation. Noninvasive techniques (Pimax, Pemax, snifftest) are available to explore the strength of respiratory muscles. Sleep is characterized by a long period of hypoventilation, essentially during REM-sleep. There are no guidelines concerning the appropriate mode, type and rhythm of explorations of diurnal and nocturnal respiratory functions.

Amyotrophic Lateral Sclerosis↗

Paw preference, rotation, and dopamine function in Collins HI and LO mouse strains.

Mice have paw preferences that are consistent upon repeated measurement. The Collins HI and LO strains are two populations of mice that have been selectively bred to differ markedly in the degree of paw preference. They represent a unique genetic model of functional cerebral lateralization. Rotation (or circling) behavior in normal unlesioned animals reflects an endogenous lateralization of the functioning brain dopamine (DA) systems. In the present study, rotational behavior and lateralized brain DA neurochemistry were assessed in the Collins HI and LO strain mice. Confirming Collins findings, HI strain mice exhibited stronger paw preferences than LO strain mice. HI strain mice also showed stronger percent directional preferences during nocturnal tests of spontaneous rotation. Neurochemical differences were also apparent between the strains. DA and its metabolites were measured in the medial prefrontal cortex (PFC), nucleus accumbens (NAS), and striatum. Degrees of rotational and paw preference in HI, but not LO, mice were correlated with PFC asymmetries in DA and the DA metabolite dihydroxyphenyl acetic acid (DOPAC), respectively. Hemisphere, paw preference, turning preference, and strain interacted in a complex way to determine measures of DA utilization in the NAS and striatum. Even though the directions of paw preference and rotation were not correlated, HI and LO mice of differing paw and rotational directional preferences showed differences in DA neurochemistry in the NAS and striatum.

Animals↗

Insulin resistance, dietary fat intake and blood pressure predict left ventricular diastolic function 20 years later.

BACKGROUND AND AIMS: Our knowledge on the development of left ventricular diastolic dysfunction is scarce. Thus, we aimed to investigate the relationship between left ventricular diastolic function and a wide variety of cardiovascular risk factors, including dietary factors using both cross-sectional and longitudinal data with 20 years follow-up. METHOD AND RESULTS: A population-based cohort of 505 50-year-old men was examined with determinations of blood pressure, insulin, glucose and fatty acid composition of serum cholesterol esters. A reinvestigation 20 years later also included hyperinsulinaemic euglycaemic clamp, 7-day diet record and Doppler echocardiography with determination of left ventricular diastolic function (early (E) and late (A) peak mitral velocities and left atrial diameter). Blood pressure both at age 50 and 70 was negatively correlated to the E/A ratio (r=-0.15, p<0.001 and r=-0.23, p<0.001) at age 70. Insulin resistance at age 50 and 70 were negatively correlated to the A-wave and left atrial diameter at follow-up. A fatty acid profile indicating a diet high in saturated fats at age 50 was correlated to an increased left atrial diameter 20 years later and the dietary intake of fat was negatively correlated to the E/A ratio (r=-0.09, p<0.05) at age 70. All findings were independent of myocardial infarction and cardiovascular medication. CONCLUSION: Apart from blood pressure, insulin resistance and dietary fat intake predicted left ventricular diastolic function after 20 years. These findings suggest that both hemodynamic and metabolic factors may play a role for left ventricular diastolic function and disclose new possibilities for prevention of left ventricular diastolic dysfunction.

Aged↗