Neuroscience letters
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Neuroscience letters · Apr 2009
Anatibant, a selective non-peptide bradykinin B2 receptor antagonist, reduces intracranial hypertension and histopathological damage after experimental traumatic brain injury.
Bradykinin, the main metabolite of the kallikrein-kinin system and one of the first mediators released during inflammation, is well known to increase the permeability of the blood brain barrier (BBB) by activation of kinin B2 receptors and hence promote brain edema formation following traumatic brain injury (TBI). Anatibant (LF 16-0687), a selective non-peptide bradykinin B2 receptor antagonist, reduces brain edema after experimental TBI, however, so far no data are available if Anatibant reduces also the sequels of brain edema formation, i.e. morphological brain damage. Therefore, we investigated the effect of Anatibant (3.0 mg/kg b.w.) on intracranial pressure (ICP) and contusion volume after experimental TBI. ⋯ ICP was measured 3, 6, and 10 h after injury and contusion volume was quantified 24 h after trauma. Our data demonstrate a significant reduction of ICP (16.6+/-1.67 mmHg vs. 24.40+/-3.58 mmHg; n=6; p=0.002) and of contusion volume 24 h after trauma (28.28+/-5.18 mm3 vs. 35.0+/-3.32 mm3 n=7; p=0.003) in treated mice. Therefore we conclude, that inhibition of bradykinin B2 receptors seems to be a promising treatment option, and might therefore be investigated in clinical trails for the treatment of TBI.
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Neuroscience letters · Apr 2009
Electrophysiology reveals semantic priming at a short SOA irrespective of depth of prime processing.
The otherwise robust behavioral semantic priming effect is reduced to the point of being absent when a letter search has to be performed on the prime word. As a result the automaticity of semantic activation has been called into question. It is unclear, however, in how far automatic processes are even measurable in the letter search priming paradigm as the prime task necessitates a long prime-probe stimulus-onset asynchrony (SOA). ⋯ Stimuli were presented at two different SOAs (240 ms vs. 840 ms) and participants performed either a grammatical discrimination (Experiment 1) or a letter search (Experiment 2) on the prime. Irrespective of prime task, the modulation of the N400, the ERP correlate of semantic activation, provided clear-cut evidence of semantic processing at the short SOA. Implications for theories of semantic activation as well as the constraints of the delayed prime task procedure are discussed.