Visual Motion Responses in the Posterior Cingulate Sulcus: A Comparison to V5/MT and MST

Motion processing regions apart from V5+/MT+ are still relatively poorly understood. Here, we used functional magnetic resonance imaging to perform a detailed functional analysis of the recently described cingulate sulcus visual area (CSv) in the dorsal posterior cingulate cortex. We used distinct types of visual motion stimuli to compare CSv with V5/MT and MST, including a visual pursuit paradigm. Both V5/MT and MST preferred 3D flow over 2D planar motion, responded less yet substantially to random motion, had a strong preference for contralateral versus ipsilateral stimulation, and responded nearly equally to contralateral and to full-field stimuli. In contrast, CSv had a pronounced preference to 2D planar motion over 3D flow, did not respond to random motion, had a weak and nonsignificant lateralization that was significantly smaller than that of MST, and strongly preferred full-field over contralateral stimuli. In addition, CSv had a better capability to integrate eye movements with retinal motion compared with V5/MT and MST. CSv thus differs from V5+/MT+ by its unique preference to full-field, coherent, and planar motion cues. These results place CSv in a good position to process visual cues related to self-induced motion, in particular those associated to eye or lateral head movements

Multimodal imaging Gd-nanoparticles functionalized with Pittsburgh compound B or a nanobody for amyloid plaques targeting

International audienceGadolinium-based nanoparticles were functionalized with either the Pittsburgh compound B or a nanobody (B10AP) in order to create multimodal tools for an early diagnosis of amyloidoses.MATERIALS & METHODS:The ability of the functionalized nanoparticles to target amyloid fibrils made of β-amyloid peptide, amylin or Val30Met-mutated transthyretin formed in vitro or from pathological tissues was investigated by a range of spectroscopic and biophysics techniques including fluorescence microscopy.RESULTS:Nanoparticles functionalized by both probes efficiently interacted with the three types of amyloid fibrils, with KD values in 10 micromolar and 10 nanomolar range for, respectively, Pittsburgh compound B and B10AP nanoparticles. Moreover, they allowed the detection of amyloid deposits on pathological tissues.CONCLUSION:Such functionalized nanoparticles could represent promising flexible and multimodal imaging tools for the early diagnostic of amyloid diseases, in other words, Alzheimer's disease, Type 2 diabetes mellitus and the familial amyloidotic polyneuropathy

Gd-nanoparticles functionalization with specific peptides for ß-amyloid plaques targeting.

AmylDi

Synthesis and characterization of multimodal Gd-Nanoparticles vectorized for Amyloidosis diagnosis, and their affinity evaluation using Biacore.

International audienceAmyloidosis is a systemic disorder in which proteins form insoluble aggregates (or fibrils) in extracellular tissues. Depending of the protein nature and its deposition area, this accumulation could lead to different pathologies. In this project, we focus on three kind of amyloidosis forms: i) Amyloid Aβ, ii) Islet Amyloid PolyPeptide IAPP, iii) Transthyretin TTR, which are respectively responsible of Alzheimer Disease, type II diabetes and finely cardiomyopathy and polyneuropathy. We are investigating two different strategies to target the fibrils: i) Camelid heavy chain antibody fragment (or Nanobody)[1], ii) Peptides derived from the protein responsible of the aggregate

Synthesis and characterization of multimodal Gd-Nanoparticles vectorized for Amyloidosis diagnosis, and their affinity evaluation using Biacore.

International audienceAmyloidosis is a systemic disorder in which proteins form insoluble aggregates (or fibrils) in extracellular tissues. Depending of the protein nature and its deposition area, this accumulation could lead to different pathologies. In this project, we focus on three kind of amyloidosis forms: i) Amyloid Aβ, ii) Islet Amyloid PolyPeptide IAPP, iii) Transthyretin TTR, which are respectively responsible of Alzheimer Disease, type II diabetes and finely cardiomyopathy and polyneuropathy. We are investigating two different strategies to target the fibrils: i) Camelid heavy chain antibody fragment (or Nanobody)[1], ii) Peptides derived from the protein responsible of the aggregate

Gd-nanoparticles functionalization with specific peptides for ß-amyloid plaques targeting

Amyloidoses are characterized by the extracellular deposition of insoluble fibrillar proteinaceous aggregates highly organized into cross-β structure and referred to as amyloid fibrils. Nowadays, the diagnosis of these diseases remains tedious and involves multiple examinations while an early and accurate protein typing is crucial for the patients' treatment. Routinely used neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) using Pittsburgh compound B, [11C]PIB, provide structural information and allow to assess the amyloid burden, respectively, but cannot discriminate between different amyloid deposits. Therefore, the availability of efficient multimodal imaging nanoparticles targeting specific amyloid fibrils would provide a minimally-invasive imaging tool useful for amyloidoses typing and early diagnosis. In the present study, we have functionalized gadolinium-based MRI nanoparticles (AGuIX) with peptides highly specific for Aβ amyloid fibrils, LPFFD and KLVFF. The capacity of such nanoparticles grafted with peptide to discriminate among different amyloid proteins, was tested with Aβ(1–42) fibrils and with mutated-(V30M) transthyretin (TTR) fibrils