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Camp Krogsgaard posted an update 10 days ago
The architecture of brain networks has been extensively studied in multiple species. However, exactly how the brain network reconfigures when a local region, particularly a hub region, stops functioning remains elusive. By combining chemogenetics and resting-state functional magnetic resonance imaging (rsfMRI) in an awake rodent model, we investigated the causal impact of acutely inactivating a hub region (i.e. the dorsal anterior cingulate cortex) on brain network properties. We found that suppressing neural activity in a hub could have a ripple effect that went beyond the hub-related connections and propagated to other neural connections across multiple brain systems. In addition, hub dysfunction affected the topological architecture of the whole-brain network in terms of the network resilience and segregation. Selectively inhibiting excitatory neurons in the hub further changed network integration. None of these changes were observed in sham rats or when a non-hub region (i.e. the primary visual cortex) was perturbed. This study has established a system that allows for mechanistically dissecting the relationship between local regions and brain network properties. M344 ic50 Our data provide direct evidence supporting the hypothesis that acute dysfunction of a brain hub can cause large-scale network changes. These results also provide a comprehensive framework documenting the differential impact of hub versus non-hub nodes on network dynamics.Accurate detection and quantification of unruptured intracranial aneurysms (UIAs) is important for rupture risk assessment and to allow an informed treatment decision to be made. Currently, 2D manual measures used to assess UIAs on Time-of-Flight magnetic resonance angiographies (TOF-MRAs) lack 3D information and there is substantial inter-observer variability for both aneurysm detection and assessment of aneurysm size and growth. 3D measures could be helpful to improve aneurysm detection and quantification but are time-consuming and would therefore benefit from a reliable automatic UIA detection and segmentation method. The Aneurysm Detection and segMentation (ADAM) challenge was organised in which methods for automatic UIA detection and segmentation were developed and submitted to be evaluated on a diverse clinical TOF-MRA dataset. A training set (113 cases with a total of 129 UIAs) was released, each case including a TOF-MRA, a structural MR image (T1, T2 or FLAIR), annotation of any present UIA(s) and theethod, after selection of true UIAs, was similar to interobserver performance. The ADAM challenge remains open for future submissions and improved submissions, with a live leaderboard to provide benchmarking for method developments at https//adam.isi.uu.nl/.
Metabotropic glutamate receptor subtype 5 (mGluR5) is integral to the brain glutamatergic system and cognitive function. This study investigated whether aging is associated with decreased brain mGluR5 availability.
Cognitively normal participants (n=45), aged 18 to 84 years, underwent FPEB positron emission tomography scans to quantify brain mGluR5. Distribution volume (V
) was computed using a venous or arterial input function and equilibrium modeling from 90 to 120min. In the primary analysis, the association between age and V
in the hippocampus and association cortex was evaluated using a linear mixed model. Exploratory analyses assessed the association between age and V
in multiple brain regions. The contribution of gray matter tissue alterations and partial volume effects to associations with age was also examined.
In the primary analysis, older age was associated with lower FPEB binding to mGluR5 (P=0.026), whereas this association was not significant after gray matter masking or partial volume correction to account for age-related tissue loss. Post hoc analyses revealed an age-related decline in mGluR5 availability in the hippocampus of 4.5% per decade (P=0.007) and a non-significant trend in the association cortex (P=0.085). An exploratory analysis of multiple brain regions revealed broader inverse associations of age with mGluR5 availability, but not after partial volume correction.
Reductions in mGluR5 availability with age appear to be largely mediated by tissue loss. Quantification of FPEB binding to mGluR5 may expand our understanding of age-related molecular changes and the relationship with brain tissue loss.
Reductions in mGluR5 availability with age appear to be largely mediated by tissue loss. Quantification of FPEB binding to mGluR5 may expand our understanding of age-related molecular changes and the relationship with brain tissue loss.
X-linked hypophosphataemia (XLH) is conventionally managed with oral phosphate and active vitamin D analogues.
To evaluate long term treatment response by assessing biochemical disease activity , radiological rickets severity score (RSS), growth and morbidity in patients with XLH on conventional therapy and assess the correlation between serum ALP and RSS.
XLH patients from 3 UK tertiary centres with ≥3 radiographs one year apart were included. Data was collected retrospectively. The RSS was assessed from routine hand and knee radiographs and ALP z scores were calculated using age-specific reference data.
Thirty-eight (male=12) patients met the inclusion criteria. The mean±SD knee, wrist and total RSS at baseline (median age 1.2years) were 2.0±1.2, 1.9±1.2 and 3.6±1.3 respectively; and at the most recent clinic visit (median age 9.0years, range 3.3-18.9) were 1.6±1.0, 1.0±1.0 and 2.5±1.5 respectively. The mean±SD serum ALP z scores at baseline and the most recent visit were 4.2±2.3 and 4.0±3.3. Median height SDS at baseline and most recent visit were -1.2 and -2.1 (p=0.05). Dental abscess, craniosynostosis, limb deformity requiring orthopaedic intervention and nephrocalcinosis were present in 31.5%, 7.9%, 31.6% and 42.1% of the cohort respectively. There was no statistically significant (p>0.05) correlation between ALP z scores and knee (r=0.07) or total (r=0.12) RSS.
Conventional therapy was not effective in significantly improving biochemical and radiological features of disease. The lack of association between serum ALP and rickets severity on radiographs limits the value of ALP as the sole indicator of rickets activity in patients receiving conventional therapy.
Conventional therapy was not effective in significantly improving biochemical and radiological features of disease. The lack of association between serum ALP and rickets severity on radiographs limits the value of ALP as the sole indicator of rickets activity in patients receiving conventional therapy.
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Start with a huge, uncovered box, or even a kiddie pool, and fill with a thick layer (about 6 inches) of unscented clay or fine sand-like particulate clumping/scoopable litter. For Ollie, you may need to play around with the substrate types to make it more natural. Try using soil or peat.