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Cortical granule exocytosis is important for the block to polyspermy at fertilization in the eggs of most vertebrates and many invertebrates. Cortical granules are poised at the cell surface and exocytose in response to sperm stimulation. Following exocytosis, the cortical granule contents modify the extracellular environment of the egg, the major result of which is to block additional sperm bi...

The reaction elicited by a neutral stimulus has been commonly cailed ''orienting response" and many of its peculiarities have been analyzed (Pavlov 1951). Sokolov (1963) indicated that this sevonse is non specific regarding quality anld htensity of the stimulus and that its repetition provokles the extinction of the orienting response. Different components of the respolnse have been pointed out...

Optimization of cognitive processing may depend on specific and distinct functions of the cortical cholinergic and noradrenergic systems. This investigation dissociates functions of cortical acetylcholine (ACh) and noradrenaline (NA) in arousal and visual attention by simultaneously measuring ACh and NA efflux in the rat prefrontal cortex during sustained attentional performance. The five-choic...

Background and Purpose—The 3 gene products of the Na /Ca exchanger (NCX), viz, NCX1, NCX2, and NCX3, may play a pivotal role in the pathophysiology of brain ischemia. The aim of this study was to investigate the transductional and posttranslational mechanisms involved in the expression of these isoforms during oxygen and glucose deprivation and their role in endoplasmic reticulum Ca refilling i...

Topographical evaluation of aphasic brain lesions can enhance our knowledge of cognitive physiology and plasticity. This prospective study was conducted on 100 stroke-afflicted patients with aphasia admitted in Valie-Asr Hospital (Khorasan, Iran) in 2003. Topography of infarct lesions was detected by a neurologist based on the map of brain vascular territories in CT-scan. Aphasic lesions catego...

The folding patterns of the brain vary dramatically across species. Moreover, the location of sulcal (valley) and gyral (ridge) folds differ considerably in terms of their size, shape and extent even within a species. A paradigm for cortical pattern formation within or across species has not become apparent. Discussions as to how cortical folding patterns occur have recently emerged in the lite...