Postsynaptic muscarinic m2 receptors at cholinergic and glutamatergic synapses of mouse brainstem motoneurons

In many brain areas, few cholinergic synapses are identified. Acetylcholine is released into the extracellular space and acts through diffuse transmission. Motoneurons, however, are contacted by numerous cholinergic terminals, indicating synaptic cholinergic transmission on them. The muscarinic m2 receptor is the major acetylcholine receptor subtype of motoneurons; therefore, we analyzed the localization of the m2 receptor in correlation with synapses by electron microscopic immunohistochemistry in the mouse trigeminal, facial, and hypoglossal motor nuclei. In all nuclei, m2 receptors were localized at the membrane of motoneuronal perikarya and dendrites. The m2 receptors were concentrated at cholinergic synapses located on the perikarya and most proximal dendrites. However, m2 receptors at cholinergic synapses represented only a minority (<10%) of surface m2 receptors. The m2 receptors were also enriched at glutamatergic synapses in both motoneuronal perikarya and dendrites. A relatively large proportion (20–30%) of plasma membrane–associated m2 receptors were located at glutamatergic synapses. In conclusion, the effect of acetylcholine on motoneuron populations might be mediated through a synaptic as well as diffuse type of transmission. J. Comp. Neurol. 521:2008–2024, 2013. © 2012 Wiley Periodicals, Inc.     

Cerebrovascular hemodynamic changes in multiple sclerosis patients during head-up tilt table test: effect of high-dose intravenous steroid treatment

Demyelination in multiple sclerosis (MS) may cause damage to the vegetative nervous system. Our objective was to examine cerebral autoregulation assessed via blood pressure and cerebral blood flow velocity fluctuations during head-up tilt table testing. We also investigated the effects of high-dose intravenous corticosteroid treatment. Transcranial Doppler registration of middle cerebral artery blood flow velocity and continuous blood pressure and heart rate monitoring were performed at rest and during tilt table testing in 30 MS patients. Ten age-matched healthy subjects were also examined as controls. Correlations between mean arterial blood pressure (MBP) and cerebral blood flow velocity (CBF) fluctuations were averaged, yielding the correlation coefficient index Mx. For a subgroup of 11 patients with acute exacerbations, results were also evaluated before and after methylprednisolone treatment (1 g/day intravenously for 5 days). No significant differences in the autoregulatory indices were seen between patients and controls, or between pre- and post-steroid results. Modeling CBF velocity changes associated with a 1-mmHg increase in MBP, significant differences (p < 0.05) were detected in patients vs. controls, and also after vs. before steroid administration. We conclude that cerebrovascular autoregulation impairments are detectable in early phase MS. Corticosteroid treatment has a significant effect on hemodynamic changes in acute exacerbations.     

The Global Burden of Surgical Management of Osteoporotic Fractures

World Journal of Surgery - Osteoporosis is an epidemic in the developed world. Fracture is a major burden associated with osteoporosis. Surgical management is recommended for particular anatomical...     

Rapid in silico selection of an MCHR1 antagonists’ focused library from multi-million compounds’ repositories: biological evaluation

Target-focused libraries can be rapidly selected by 2D virtual screening methods from multimillion compounds’ databases if structures of active compounds are available. In the present study, a multi-step virtual and in vitro screening cascade is used to select melanin-concentrating hormone receptor-1 antagonists. The 2D similarity search combined with physico-chemical parameter filtering is suitable for selecting candidates from multimillion compounds’ repository. The seeds of the first round of virtual screening were collected from literature commercial databases, whereas the seeds of the second round were the hits the first round of biological testing In vitro screening underlined the efficiency of our approach, as in the second screening round the hit rate (8.6 %) significantly improved compared to the first round (1.9 %), applying a strict requirement for hit selection, and also this cascade-like screening method was appropriate for selecting several compounds reaching efficacies even below 10 nM.     

Mortality and Long-Term Outcome of Neonates with Congenital Heart Disease and Acute Perinatal Stroke: A Population-Based Case-Control Study

Objective: Neonates with congenital heart disease (CHD) and perinatal stroke have high mortality and survivors are at risk for poor long-term neurodevelopmental outcome. The aim of this study was to assess the risk factors and outcome of neonates with both CHD and MRI-confirmed perinatal stroke (Study Group) and compare those to the risk factors and outcome of infants matched for CHD without stroke (Control-1) and of infants matched for MRI-confirmed stroke without CHD (Control-2). Methods: We conducted a population-based case-control study enrolling 28 term neonates with CHD and MRI-confirmed acute perinatal stroke born between 2007–2017 in the Central-Hungarian Region. Each of the control groups included 56 infants. The Bayley Scales of Infant Development-II, the Brunet-Lézine test and the Binet Intelligence scales-V were used for neurodevelopmental follow-up at a median age of 61 months. Results: Mortality was highest in the Study Group (25% compared to 5% and 2%, respectively, p = 0.001). Adverse neurodevelopmental outcome was prevalent in the Study (53%) and Control-2 Groups (52%, p = 0.03). Significantly different parameters among the three groups included Apgar scores, mode of delivery, gestational age at birth, cardiac interventions and twin pregnancy. In a multivariable regression analysis adjusted for clinically relevant parameters, patients in the Study Group had significantly higher odds for mortality compared to patients in the Control-1 Group (OR: 6.5 95% CI: 1.1–39.4). Conclusions: Neonates with perinatal stroke and CHD are at a higher risk for dying compared to neonates with CHD without stroke. In addition, the stroke-associated direct insult to the brain likely plays an important role in the development of neurodevelopmental morbidity in these patients.