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The glial water channel aquaporin-4 (AQP4) has been hypothesized to modulate water and potassium fluxes associated with neuronal activity. In this study, we examined the seizure phenotype of AQP4 -/- mice using in vivo electrical stimulation and electroencephalographic (EEG) recording. AQP4 -/- mice were found to have dramatically prolonged(More)
Aquaporin-4 (AQP4) is a water-selective transport protein expressed in glial cells throughout the central nervous system. AQP4 deletion in mice produces alterations in several neuroexcitation phenomena, including hearing, vision, epilepsy, and cortical spreading depression. Here, we report defective olfaction and electroolfactogram responses in AQP4-null(More)
Diffusion in brain extracellular space (ECS) is important for nonsynaptic intercellular communication, extracellular ionic buffering, and delivery of drugs and metabolites. We measured macromolecular diffusion in normally light-inaccessible regions of mouse brain by microfiberoptic epifluorescence photobleaching, in which a fiberoptic with a micron-size tip(More)
Aquaporin-4 (AQP4) is a water transport protein expressed in glial cell plasma membranes, including glial cell foot processes lining the blood-brain barrier. AQP4 deletion in mice reduces cytotoxic brain edema produced by different pathologies. To determine whether AQP4 is rate-limiting for brain water accumulation and whether altered AQP4 expression, as(More)
OBJECTIVE Bypass surgery for brain aneurysms is evolving from extracranial-intracranial (EC-IC) to intracranial-intracranial (IC-IC) bypasses that reanastomose parent arteries, revascularize efferent branches with in situ donor arteries or reimplantation, and reconstruct bifurcated anatomy with grafts that are entirely intracranial. We compared results with(More)
The effect of acute brief seizures on neocortical c-fos expression was investigated in rats injected with 5 mg/kg 4-aminopyridine. Electroencephalography in freely moving animals with implanted neocortical electrodes detected an average of 2.67 tonic-clonic convulsions within 1 h following the 4-AP treatment. Tissue samples of the somatosensory neocortex(More)
We examined the effects of non-competitive NMDA glutamate receptor antagonists on seizures elicited by 4-aminopyridine (4-AP), and in particular, on the expression of the transcription factor c-fos induced by these seizures. Induction of c-fos mRNA due to 4-AP-elicited seizures was ascertained by reverse transcription polymerase chain reaction in samples of(More)
Cerebral edema contributes significantly to morbidity and mortality after brain injury and stroke. Aquaporin-4 (AQP4), a water channel expressed in astrocytes, plays a key role in brain water homeostasis. Genetic variants in other aquaporin family members have been associated with disease phenotypes. However, in human AQP4, only one non-synonymous(More)
BACKGROUND The eyebrow craniotomy is a less invasive alternative approach for accessing anterior skull base lesions, compared to traditional and more extensive exposures. We give a stepwise description of this minimally invasive technique with discussion on the indications, limitations and key aspects of perioperative management. METHODS Positioning of(More)
The regulation of water balance in the brain is crucial. A disruption in this equilibrium causes an increase in brain water content that significantly contributes to the pathophysiology of traumatic brain injury, hydrocephalus, and a variety of neurological disorders. The discovery of the aquaporin (AQP) family of membrane water channels has provided(More)