Extra-Visual Functional and Structural Connection Abnormalities in Leber's Hereditary Optic Neuropathy

We assessed abnormalities within the principal brain resting state networks (RSNs) in patients with Leber's hereditary optic neuropathy (LHON) to define whether functional abnormalities in this disease are limited to the visual system or, conversely, tend to be more diffuse. We also defined the structural substrates of fMRI changes using a connectivity-based analysis of diffusion tensor (DT) MRI data. Neuro-ophthalmologic assessment, DT MRI and RS fMRI data were acquired from 13 LHON patients and 13 healthy controls. RS fMRI data were analyzed using independent component analysis and SPM5. A DT MRI connectivity-based parcellation analysis was performed using the primary visual and auditory cortices, bilaterally, as seed regions. Compared to controls, LHON patients had a significant increase of RS fluctuations in the primary visual and auditory cortices, bilaterally. They also showed decreased RS fluctuations in the right lateral occipital cortex and right temporal occipital fusiform cortex. Abnormalities of RS fluctuations were correlated significantly with retinal damage and disease duration. The DT MRI connectivity-based parcellation identified a higher number of clusters in the right auditory cortex in LHON vs. controls. Differences of cluster-centroid profiles were found between the two groups for all the four seeds analyzed. For three of these areas, a correspondence was found between abnormalities of functional and structural connectivities. These results suggest that functional and structural abnormalities extend beyond the visual network in LHON patients. Such abnormalities also involve the auditory network, thus corroborating the notion of a cross-modal plasticity between these sensory modalities in patients with severe visual deficits

Palynology of Iron Age and Gallo-Roman archaeological sediments from Beaurieux Les Grèves, Aisne, France

Pollen and non-pollen palynomorph analyses conducted on archaeological sediments from ditches and pits are used to investigate land-use and vegetation history around the long-lived rural settlement of Beaurieux Les Grèves in the Aisne valley, Picardy, northern France. Samples were examined from successive phases spanning the 8th century bc to the 3rd century ad. Each phase showed evidence of agriculture and human impact on the environment. The earliest occupation was during the early Iron Age, and the area around the site was shown to have been almost completely deforested and mainly pasture. The later Iron Age supported mixed agriculture, probably with pasture around the settlement site and cereal fields further away. In Gallo-Roman times there was mixed farming with considerable cereal cultivation, although the area near the site was mainly pasture or abandoned land. Late Gallo-Roman times saw a reduction in agricultural activity and some regeneration of heath and scrub vegetation. Coprophilous fungal spores are conspicuous and indicate the importance of animal husbandry on and around the site. The data from Beaurieux Les Grèves augment earlier analyses from settlements and natural deposits in the Aisne valley in suggesting almost complete deforestation for agricultural land use within the valley bottom, although some woodland undoubtedly survived on the steeper valley sides and nearby plateaux. It agrees with the pollen evidence from the wider region of north-eastern France that shows clearance of Fagus-dominated woodland for mixed agriculture in late Iron Age and Gallo-Roman times, and increasingly for arable cultivation. This was responsible for effecting a transformation from a partly wooded to a mainly open landscape