Increased body mass index is associated with specific regional alterations in brain structure.

BACKGROUND: Although obesity is associated with structural changes in brain grey matter, findings have been inconsistent and the precise nature of these changes is unclear. Inconsistencies may partly be due to the use of different volumetric morphometry methods, and the inclusion of participants with comorbidities that exert independent effects on brain structure. The latter concern is particularly critical when sample sizes are modest. The purpose of the current study was to examine the relationship between cortical grey matter and body mass index (BMI), in healthy participants, excluding confounding comorbidities and using a large sample size. SUBJECTS: A total of 202 self-reported healthy volunteers were studied using surface-based morphometry, which permits the measurement of cortical thickness, surface area and cortical folding, independent of each other. RESULTS: Although increasing BMI was not associated with global cortical changes, a more precise, region-based analysis revealed significant thinning of the cortex in two areas: left lateral occipital cortex (LOC) and right ventromedial prefrontal cortex (vmPFC). An analogous region-based analysis failed to find an association between BMI and regional surface area or folding. Participants' age was also found to be negatively associated with cortical thickness of several brain regions; however, there was no overlap between the age- and BMI-related effects on cortical thinning. CONCLUSIONS: Our data suggest that the key effect of increasing BMI on cortical grey matter is a focal thinning in the left LOC and right vmPFC. Consistent implications of the latter region in reward valuation, and goal control of decision and action suggest a possible shift in these processes with increasing BMI.

Novel approaches for scanning near-field optical microscopy imaging of oligodendrocytes in culture.

Newborn rat oligodendrocyte cultures were investigated by scanning near-field optical microscope (SNOM), a versatile new tool able to map cell membranes in 3D and simultaneously obtain images of the cytoplasm. Topography, error, transmission and reflection signals were acquired to describe cell morphology with nanometer-scale resolution. Oligodendrocytes were studied as a model because their extensive membrane processes (typical of their physiological role in myelination) made them particularly suitable to test the sensitivity of the new method. Furthermore, we combined a classical histochemical method with SNOM, to identify specific intracellular proteins at high definition. In particular, with this technique, cytoskeleton elements of oligodendrocytes, such as microtubules, were observed with tubulin antibodies. Images obtained with SNOM were also compared with those from conventional scanning electron microscopy (SEM) and optical microscopy. Our results showed that SNOM allowed to observe cell nanostructures otherwise undetectable all together with other microscopies. In conclusion, SNOM, combined with rapid and non-invasive methods of specimen preparation, appears to be a powerful tool that can offer new possibilities in the field of neuroscience imaging at nano-scale level.

[Neurosurgical treatment of children with spina bifida associated with congenital spinal lipoma in the lumbosacral region]. / Neurokirursko lijecenje djece sa spinom bifidom udruzenom sa spinalnim kongenitalnim lipomom u lumbosakralnom podrucju.

This paper presents twelve neurosurgically treated children with spina bifida associated with congenital spinal lumbosacral lipoma over a 3-year period. The introduction deals with various types of lipoma, their development, clinical presentation, local findings in children with spinal lipoma, as well as with the significance of neurosurgical treatment. The age span of children with occult spina bifida and spinal lumbosacral lipoma was from 3 months to 2 years, and there were seven girls and five boys. In all the twelve children, a smaller or bigger fatty mass in the lumbosacral area was noticed immediately after birth, gradually increasing in size. Neurologic examination revealed weakness of lower extremities, with somewhat atonic sphincters, in only two of the children. Spinal dysraphism was demonstrated by plain roentgenograms in all the twelve children, while CT-scans, CT-myelography and recently MR-scans, confirmed the diagnosis of spinal lipoma. In all the twelve children the spinal lipoma and the adherences between the lipoma and the low-lying conus or an enlarged filum terminale were removed by the neurosurgical excision. Follow-up of children 6 and more months following the surgery showed improvement of their condition. Spina bifida associated with congenital spinal lumbosacral lipoma is a condition that although benign in histology, can have devastating effects if not surgically corrected early. Children who are asymptomatic at the time of repair will tend to remain asymptomatic. Those who are not repaired early will develop and show subsequent deterioration as time progresses.(ABSTRACT TRUNCATED AT 250 WORDS)