Connexin channels provide a target to manipulate brain endothelial calcium dynamics and blood-brain barrier permeability.

The cytoplasmic Ca(2+) concentration ([Ca(2+)](i)) is an important factor determining the functional state of blood-brain barrier (BBB) endothelial cells but little is known on the effect of dynamic [Ca(2+)](i) changes on BBB function. We applied different agonists that trigger [Ca(2+)](i) oscillations and determined the involvement of connexin channels and subsequent effects on endothelial permeability in immortalized and primary brain endothelial cells. The inflammatory peptide bradykinin (BK) triggered [Ca(2+)](i) oscillations and increased endothelial permeability.

Influence of an increased intracranial pressure on cerebral and systemic haemodynamics during endoscopic neurosurgery: an animal model.

Background: During endoscopic neurosurgery, direct mechanical stimulation of the brain by the endoscope and increased intracranial pressure (ICP) caused by the continuous rinsing can induce potentially lethal haemodynamic reflexes, brain ischaemia, and excessive fluid resorption.

Methods: In a newly presented rat model of endoscopic neurosurgery, stereotactic access to the cerebrospinal fluid was secured and the ICP was increased by controlled infusion until complete suppression of the cerebral perfusion pressure (CPP). The haematocrit (Hct) level was determined before and after the procedure.