An evolutionary gap in primate default mode network organization

The human default mode network (DMN) is engaged at rest and in cognitive states such as self-directed thoughts. Interconnected homologous cortical areas in primates constitute a network considered as the equivalent. Here, based on a cross-species comparison of the DMN between humans and non-hominoid primates (macaques, marmosets, and mouse lemurs), we report major dissimilarities in connectivity profiles. Most importantly, the medial prefrontal cortex (mPFC) of non-hominoid primates is poorly engaged with the posterior cingulate cortex (PCC), though strong correlated activity between the human PCC and the mPFC is a key feature of the human DMN. Instead, a fronto-temporal resting-state network involving the mPFC was detected consistently across non-hominoid primate species. These common functional features shared between non-hominoid primates but not with humans suggest a substantial gap in the organization of the primate\u27s DMN and its associated cognitive functions

A consensus protocol for functional connectivity analysis in the rat brain

Task-free functional connectivity in animal models provides an experimental framework to examine connectivity phenomena under controlled conditions and allows for comparisons with data modalities collected under invasive or terminal procedures. Currently, animal acquisitions are performed with varying protocols and analyses that hamper result comparison and integration. Here we introduce StandardRat, a consensus rat functional magnetic resonance imaging acquisition protocol tested across 20 centers. To develop this protocol with optimized acquisition and processing parameters, we initially aggregated 65 functional imaging datasets acquired from rats across 46 centers. We developed a reproducible pipeline for analyzing rat data acquired with diverse protocols and determined experimental and processing parameters associated with the robust detection of functional connectivity across centers. We show that the standardized protocol enhances biologically plausible functional connectivity patterns relative to previous acquisitions. The protocol and processing pipeline described here is openly shared with the neuroimaging community to promote interoperability and cooperation toward tackling the most important challenges in neuroscience

Mean amplitude of low frequency fluctuations measured by fMRI at 11.7 T in the aging brain of mouse lemur primate

Non-human primates are a critical species for the identification of key biological mechanisms in normal and pathological aging. One of these primates, the mouse lemur, has been widely studied as a model of cerebral aging or Alzheimer's disease. The amplitude of low-frequency fluctuations of blood oxygenation level-dependent (BOLD) can be measured with functional MRI. Within specific frequency bands (e.g. the 0.01-0.1 Hz), these amplitudes were proposed to indirectly reflect neuronal activity as well as glucose metabolism. Here, we first created whole brain maps of the mean amplitude of low frequency fluctuations (mALFF) in young mouse lemurs (mean ± SD: 2.1 ± 0.8 years). Then, we extracted mALFF in old lemurs (mean ± SD: 8.8 ± 1.1 years) to identify age-related changes. A high level of mALFF was detected in the temporal cortex (Brodmann area 20), somatosensory areas (Brodmann area 5), insula (Brodmann areas 13-6) and the parietal cortex (Brodmann area 7) of healthy young mouse lemurs. Aging was associated with alterations of mALFF in somatosensory areas (Brodmann area 5) and the parietal cortex (Brodmann area 7)

An Automated Open-Source Workflow for Standards-Compliant Integration of Small Animal Magnetic Resonance Imaging Data

Large-scale research integration is contingent on seamless access to data in standardized formats. Standards enable researchers to understand external experiment structures, pool results, and apply homogeneous preprocessing and analysis workflows. Particularly, they facilitate these features without the need for numerous potentially confounding compatibility add-ons. In small animal magnetic resonance imaging, an overwhelming proportion of data is acquired via the ParaVision software of the Bruker Corporation. The original data structure is predominantly transparent, but fundamentally incompatible with modern pipelines. Additionally, it sources metadata from free-field operator input, which diverges strongly between laboratories and researchers. In this article we present an open-source workflow which automatically converts and reposits data from the ParaVision structure into the widely supported and openly documented Brain Imaging Data Structure (BIDS). Complementing this workflow we also present operator guidelines for appropriate ParaVision data input, and a programmatic walk-through detailing how preexisting scans with uninterpretable metadata records can easily be made compliant after the acquisition

An Automated Open-Source Workflow for Standards-Compliant Integration of Small Animal Magnetic Resonance Imaging Data

Large-scale research integration is contingent on seamless access to data in standardized formats. Standards enable researchers to understand external experiment structures, pool results, and apply homogeneous preprocessing and analysis workflows. Particularly, they facilitate these features without the need for numerous potentially confounding compatibility add-ons. In small animal magnetic resonance imaging, an overwhelming proportion of data is acquired via the ParaVision software of the Bruker Corporation. The original data structure is predominantly transparent, but fundamentally incompatible with modern pipelines. Additionally, it sources metadata from free-field operator input, which diverges strongly between laboratories and researchers. In this article we present an open-source workflow which automatically converts and reposits data from the ParaVision structure into the widely supported and openly documented Brain Imaging Data Structure (BIDS). Complementing this workflow we also present operator guidelines for appropriate ParaVision data input, and a programmatic walk-through detailing how preexisting scans with uninterpretable metadata records can easily be made compliant after the acquisition.ISSN:1662-519

Lobar hepatocellular carcinoma with ipsilateral portal vein tumor thrombosis treated with yttrium-90 glass microsphere radioembolization: preliminary results.

International audiencePortal vein tumor thrombosis (PVTT) is a common complication of hepatocellular carcinoma (HCC) and has a negative impact on prognosis. This characteristic feature led to the rationale of the present trial designed to assess the efficacy and the safety of yttrium-90 glass-microsphere treatment for advanced-stage lobar HCC with ipsilateral PVTT. 18 patients with unresectable lobar HCC and ipsilateral PVTT were treated in our institution with (90)Y-microS radioembolization. Patients were evaluated every 3 to 6 months for response, survival, and toxicity. Mean follow-up was 13.0 months (2.2-50.6). Outcomes were: complete response (n = 2), partial response (n = 13), stable disease (n = 1), and progressive disease (n = 2) giving a disease control rate of 88.9%. Four patients were downstaged. Treating lobar hepatocellular carcinoma with ipsilateral portal vein thrombosis with yttrium-90 glass-microsphere radioembolization is safe and efficacious. Further clinical trials are warranted to confirm these results and to compare (90)Y-microS with sorafenib, taking into account not only survival but also the possibility of secondary surgery for putative curative intention after downstaging

Congenital scoliosis: A frontal plane evaluation of 251 operated patients 14 years old or older at follow-up

SummaryIntroductionCongenital scoliosis, carrying an incidence between 0.5 and 1 per 1000 births, raise the problem of their evolutive potential.HypothesisSome predictive factors for the evolution of scoliotic curvature due to congenital vertebral malformation (CVM) can be found.Material and methodsThis was a retrospective multicenter study of 251 patients, at least 14 years old when evaluated at end of follow-up, with CVM and spinal deformity predominating in the frontal plane.Results38.8% of patients showed associated neurologic, visceral or orthopedic abnormalities. CVM was single in 60.6%, double in 20.3%, triple in 6.4% and multiple in 12.7% of cases. 34.1% of CVMs were thoracic. Congenital scoliosis curvature was single in 88.8% of patients, double in 10% and triple in 1.2%. Mean curvature angle was 31.7° at diagnosis (range, 0–105°) and 41.3° preoperatively (range, 10–105°). Sixty-one patients showed associated kyphosis. Mean change in postoperative curvature angle over follow-up was 1.6° (range, −20° to 38°) in the 73 patients managed by arthrodesis, −0.4° (−24° to 30°) in the 64 managed by epiphysiodesis, and 0.4° (−18° to 35°) in the 49 managed by hemivertebral (HV) resection. Results were found to correlate significantly with age at surgery for patients managed by epiphysiodesis, but not for those managed by HV resection or arthrodesis.DiscussionMore than 30% of congenital scolioses involve associated intraspinal abnormality. All CVM patients should therefore undergo medullary and spinal MRI to assess the CVM in all three planes, and the medullary canal and its content. The evolution of scoliotic curvature induced by CVM is hard to predict. Several factors are to be taken into account: CVM type, number and location, and patient age. Curvature progression may be slow or very fast. It accelerates during the peak of puberty, stabilizing with bone maturity. Surgery is mandatory in evolutive scoliosis. Four procedures may be recommended, according to type of CVM and especially to patient age: arthrodesis, convex epiphysiodesis, HV resection or rib distraction. Surgery seeks to correct the spinal deformity induced by the CVM and prevent compensatory curvature and neurologic complications, while conserving sagittal and frontal spinal balance and sparing as many levels as possible. In case of HV involvement, the procedure of choice is CVM resection, which provides 87.5% good results in this indication; the procedure is relatively safe, conservative of spinal levels, and without age limit.Level of evidenceLevel IV. Retrospective study