We isolated calcium-labile mitotic spindles from eggs of the sea urchin Lytechinus variegatus, using a low ionic strength, EGTA lysis buffer that contined 5.0 mM EGTA, 0.5 mM MgCl2, 10-50 mM PIPES, pH 6.8, with 1% Nonidet P-40 (detergent) and 20-25% glycerol. Isolated spindles were stored in EGTA buffer with 50% glycerol for 5-6 wk without deterioration. The isolated spindles were composed prim...

Objectives: Among patients with West Syndrome (WS), the underlying brain dysfunction is considered to be the major determinant of cognitive outcome. However, regardless of whether the WS type is symptomatic or cryptogenic, patients with infantile spasms may have a favourable or grim prognosis. The purpose of this study was to utilize electroencephalography (EEG) to guide treatment, and to asses...

Aging and Alzheimer’s disease (AD) are both characterized by memory impairments and sleep changes. We investigated the potential link between these disturbances, focusing on sleep spindles, involved in memory consolidation. Two episodic memory tasks were given to young and old healthy subjects, as well as to AD patients. Post-learning sleep was recorded. Sleep spindles were globally reduced in ...

BACKGROUND AND AIM The role of sleep in the enhancement of motor skills has been studied extensively in adults. We aimed to determine involvement of sleep and characteristics of spindles and slow waves in a motor skill in children. HYPOTHESIS We hypothesized sleep-dependence of skill enhancement and an association of interindividual differences in skill and sleep characteristics. METHODS 30...

A characteristic feature of mitotic spindles is the congression of chromosomes near the spindle equator, a process mediated by dynamic kinetochore microtubules. A major challenge is to understand how precise, submicrometer-scale control of kinetochore micro-tubule dynamics is achieved in the smallest mitotic spindles, where the noisiness of microtubule assembly/disassembly will potentially act ...

Sleep spindles are transients important in evaluation of sleep EEG. Matching Pursuit (MP) is a recently introduced adaptive time-frequency method of signal analysis. Iterative algorithm fits to the local signal structures waveforms from a large an redundant set. 21 channels of an overnight EEG recording were subjected to the MP decomposition. Structures corresponding to sleep spindles were chos...

The time-varying microstructure of sleep EEG spindles may have clinical significance in dementia studies and can be quantified with a number of techniques. In this paper, the sleep spindle is modeled as an AM-FM signal in terms of six parameters, three quantifying the instantaneous envelope (IE) and three quantifying the instantaneous frequency (IF) of the spindle model. An application of such ...

Sleep spindles are the most interesting hallmark of stage 2 sleep EEG. Their accurate identification in a polysomnographic signal is essential for sleep professionals to help them mark Stage 2 sleep. Sleep Spindles are also promising objective indicators for neurodegenerative disorders. Visual spindle scoring however is a tedious workload. In this paper three different approaches are used for t...