GABRB3 mutation as a cause of Ohtahara syndrome: A case report

Ohtahara syndrome (OS) is a rare early infantile epileptic encephalopathy that is characterized by an abnormal electroencephalogram (EEG) and intractable seizures. The patient of this reported case is a 4-month-old male infant delivered by cesarean section with an uneventful antenatal and neonatal period. At 2 months of age, he developed seizures that were refractory to anticonvulsants. Prolonged video EEG showed a characteristic suppression-burst pattern. We report an infant OS associated with heterozygous mutation in the GABRB3 gene.

Oscillations of pause-burst neurons in the STN correlate with the severity of motor signs in Parkinson's disease

Background. Oscillatory activity in the subthalamic nucleus (STN) in Parkinson's disease (PD) is under extensive study. While rhythmic features of local field potentials are implicated in the manifestation of PD motor signs, less is known about single unit activity (SUA). SUA parameters inside the STN show significant heterogeneity, and various firing patterns may contribute unequally to PD pathophysiology. Objectives. We searched for correlations between SUA parameters and PD motor signs, taking neuronal activity patterns into account. Methods. 829 spike trains for STN SUA were recorded during 25 DBS surgeries. We have isolated three firing patterns (tonic, irregular burst and pause-burst) and, using mixed linear models, examined several ISI parameters and burst descriptors (for the last two patterns) for their correlation with the UPDRS 3 score and bradykinesia and rigidity scores on the contralateral body side. Results. The predominance of pause-burst as opposed to tonic activity was associated with an increase in UPDRS 3 score. Oscillation scores in the alpha range correlated with bradykinesia and rigidity scores, and oscillation scores in the beta range correlated with bradykinesia score only for pause-burst neurons, while other patterns showed no correlation with PD motor signs. There was also significant negative correlation between bradykinesia score and theta oscillations for pause-burst pattern. Conclusions. Pause-burst pattern and rhythmic neurons oscillating in the alpha range may affect motor processing in the basal ganglia more prominently than other activity patterns, probably reflecting progressive switching from tonic to burst to rhythmic activity in the parkinsonian state.

Rapid Initial Morphospace Expansion and Delayed Morphological Disparity Peak in the First 100 Million Years of the Archosauromorph Evolutionary Radiation

Adaptive radiations have played a major role in generating modern and deep-time biodiversity. The Triassic radiation of the Archosauromorpha was one of the most spectacular vertebrate radiations, giving rise to many highly ecomorphologically varied lineages—including the dinosaurs, pterosaurs, and stem-crocodylians—that dominated the larger-bodied land fauna for the following 150 Ma, and ultimately gave rise to today’s > 10,000 species of birds and crocodylians. This radiation provides an outstanding testbed for hypotheses relating to adaptive radiations more broadly. Recent studies have started to characterize the tempo and mode of the archosauromorph early adaptive radiation, indicating very high initial rates of evolution, non-competitive niche-filling processes, and previously unrecognized morphological disparity even among non-crown taxa. However, these analyses rested primarily either on discrete characters or on geometric morphometrics of the cranium only, or even failed to fully include phylogenetic information. Here we expand previous 2D geometric morphometric cranial datasets to include new taxa and reconstructions, and create an analogous dataset of the pelvis, thereby allowing comparison of anatomical regions and the transition from “sprawling” to “upright” posture to be examined. We estimated morphological disparity and evolutionary rates through time. All sampled clades showed a delayed disparity peak for sum of variances and average nearest neighbor distances in both the cranium and pelvis, with disparity likely not saturated by the end of the studied time span (Late Jurassic); this contrasts with smaller radiations, but lends weight to similar results for large, ecomorphologically-varied groups. We find lower variations in pelvic than cranial disparity among Triassic-Jurassic archosaurs, which may be related to greater morphofunctional constraints on the pelvis. Contrasting with some previous work, but also confirming some previous findings during adaptive radiations, we find relatively widespread evidence of correlation between sampled diversity and disparity, especially at the largest phylogenetic scales and using average displacement rather than sum of variances as disparity metric; this also demonstrates the importance of comparing disparity metrics, and the importance of phylogenetic scale. Stem and crown archosauromorphs show a morphological diversification of both the cranium and pelvis with higher initial rates (Permian–Middle Triassic and at the base of major clades) followed by lower rates once diversification into niches has occurred (Late Triassic–Jurassic), indicating an “early burst” pattern sensu lato. Our results provide a more detailed and comprehensive picture of the early archosauromorph radiation and have significant bearing on the understanding of deep-time adaptive radiations more broadly, indicating widespread patterns of delayed disparity peaks, initial correlation of diversity and disparity, and evolutionary early bursts.

The CPGs for Limbed Locomotion–Facts and Fiction

The neuronal networks that generate locomotion are well understood in swimming animals such as the lamprey, zebrafish and tadpole. The networks controlling locomotion in tetrapods remain, however, still enigmatic with an intricate motor pattern required for the control of the entire limb during the support, lift off, and flexion phase, and most demandingly when the limb makes contact with ground again. It is clear that the inhibition that occurs between bursts in each step cycle is produced by V2b and V1 interneurons, and that a deletion of these interneurons leads to synchronous flexor–extensor bursting. The ability to generate rhythmic bursting is distributed over all segments comprising part of the central pattern generator network (CPG). It is unclear how the rhythmic bursting is generated; however, Shox2, V2a and HB9 interneurons do contribute. To deduce a possible organization of the locomotor CPG, simulations have been elaborated. The motor pattern has been simulated in considerable detail with a network composed of unit burst generators; one for each group of close synergistic muscle groups at each joint. This unit burst generator model can reproduce the complex burst pattern with a constant flexion phase and a shortened extensor phase as the speed increases. Moreover, the unit burst generator model is versatile and can generate both forward and backward locomotion.

Designing Call Auction Institutions to Eliminate Price Bubbles: Is English Dutch the Best?

The bubble-and-burst pattern in asset markets is among the most replicable results in experimental economics. Using controlled laboratory experiments, we compare mispricing in markets organized by standard double auction rules with mispricing in markets organized by two alternative sets of clock auctions. The double Dutch auction, shown to be more efficient than the double auction in past commodity market experiments, does not eliminate bubbles. However, the English Dutch auction yields prices reflective of underlying fundamentals and succeeds in taming bubbles even with inexperienced traders in a declining fundamental value environment with an increasing cash-to-asset ratio. (JEL C91, D44, G12)

Diagnostic and therapeutic experience of child with neonatal epilepsy: from ICU to home (сlinical case)

Ohtahara syndrome is the earliest of age-dependent epileptic encephalopathies, characterized by an early onset at the age of 3 months (most often the first 10 days of life), ‘suppression-burst’ pattern on EEG both in wakefulness and in sleep, resistance to standard AED therapy, a high probability of poor prognosis in the form of severe psychomotor retardation and death in infancy.

The Paradox Behind the Pattern of Rapid Adaptive Radiation: How Can the Speciation Process Sustain Itself Through an Early Burst?

Rapid adaptive radiation poses two distinct questions apart from speciation and adaptation: What happens after one speciation event and how do some lineages continue speciating through a rapid burst? We review major features of rapid radiations and their mismatch with theoretical models and speciation mechanisms. The paradox is that the hallmark rapid burst pattern of adaptive radiation is contradicted by most speciation models, which predict continuously decelerating diversification and niche subdivision. Furthermore, it is unclear if and how speciation-promoting mechanisms such as magic traits, phenotype matching, and physical linkage of coadapted alleles promote rapid bursts of speciation. We review additional mechanisms beyond ecological opportunity to explain rapid radiations: ( a) ancient adaptive alleles and the transporter hypothesis, ( b) sexual signal complexity, ( c) fitness landscape connectivity, ( d) diversity begets diversity, and ( e) plasticity first. We propose new questions and predictions connecting microevolutionary processes to macroevolutionary patterns through the study of rapid radiations.

Subacute Sclerosing Panencephalltis: Clinical and Laboratory Manifestations

We reviewed clinical and laboratory findings of 12 cases of Subacute sclerosing panencephalitis (SSPE) hospitalized at our department from 1985 to 1991. All cases were diagnosed and hospitalized at the 2nd stage. The principal clinical manifestations were mental changes, myoclonus, and frequent falls. Other clinical manifestations were ocular changes, involuntary movements, loss of social contact, and spasticity. Diagnosis was based on suppression-burst pattern in EEG and positive antibody titer to measles in serum and cerebrospinal fluid. CT scan was not diagnotic, since it was either normal or showed only non-specific cortical atrophy. Eleven patients (91, 7%) recalled a history of measles in the past. Age of onset of SSPE varied among cases and was difficult to specify precisely due to its subtle nature. None of the cases had been vaccinated against measles. SSPE is a rare disease, but is almost always fatal with prolonged suffering of the patient. Based on our experience with SSPE patients, we recommend to broaden the immunization programme against measles.