Neuroscience letters
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Neuroscience letters · Nov 2006
Comparative StudySeverity level and injury track determine outcome following a penetrating ballistic-like brain injury in the rat.
Penetrating ballistic brain injury (PBBI) is a high-energy transfer wound causing direct damage to the cerebrum. Outcome is directly related to the ballistic's anatomical path and degree of energy transfer. In this study we evaluated differences in outcome induced by altering the 'projectile' paths and severity levels of a simulated bullet wound using a newly characterized rat model of PBBI. ⋯ A unilateral caudal injury was associated with the highest degree of mortality (up to 100%) and motor dysfunction (64-100% disability). Bilateral hemispheric injuries were also potentially fatal, while the best outcomes were associated with a unilateral frontal injury (no mortality and 14-39% motor disability). These data closely resemble clinical reports of ballistic wounds to the head and further validate the rat PBBI model with the ultimate intent to investigate novel therapeutic approaches for diagnosis and treatment of the neuropathological damage associated with PBBI.
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Neuroscience letters · Nov 2006
Effect of gabaergic, glutamatergic, antipsychotic and antidepressant drugs on pilocarpine-induced seizures and status epilepticus.
This work was designed to study the influence of drugs during seizures and status epilepticus (SE) induced by pilocarpine and mortality in adult rats. Fluoxetine (10 and 20 mg/kg), NMDA (N-methyl-D-aspartate, 10 and 20 mg/kg), amitriptyline (25 and 50 mg/kg), ketamine (0.5 and 1.0 mg/kg), gabapentin (100 and 150 mg/kg) and pimozide (10 and 20 mg/kg) were administered intraperitoneally, 30 min prior to pilocarpine (400mg/kg, s.c.). The animals were observed (24h) to determine: number of peripheral cholinergic signs, tremors, stereotyped movements, seizures, SE, latency to first seizure and number of deaths after pilocarpine treatment. ⋯ Smaller and higher doses of these drugs no protected and increased pilocarpine-induced seizures and/or mortality. Gabapentin and ketamine protected against seizures and reduced the latency to first seizure. Thus, these results suggest that caution should be taken in the selection of pharmacotherapy and dosages for patients with epilepsy because of the possibility of potentiating convulsive process toxicity.
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Neuroscience letters · Sep 2006
Sensory neurons and their supporting cells located in the trigeminal, thoracic and lumbar ganglia differentially express markers of injury following intravenous administration of paclitaxel in the rat.
Paclitaxel-induced peripheral neuropathy is a sensory neuropathy that affects thousands of cancer patients each year as paclitaxel is commonly used to treat breast, non-small cell lung and ovarian cancer. To begin to define the type and location of sensory neurons most impacted by paclitaxel, we examined rat trigeminal ganglion, thoracic and lumbar dorsal root ganglion (DRG) 10 days following intravenous infusion of clinically relevant doses of paclitaxel. To define the population of cells injured by paclitaxel, we examined the expression of activating transcription factor-3 (ATF3), a marker of cell injury; to define the hypertrophy of satellite cells, we quantified the expression of the intermediate filament protein glial fibrillary acidic protein (GFAP); and to define the activation of macrophages, we examined the expression of the lysosomal protein CD68. ⋯ An increase in both GFAP immunofluorescence in satellite cells and the number of activated macrophages occurred in lumbar>thoracic>trigeminal ganglia of paclitaxel-treated rats. This differential expression of cellular markers suggests that the largest sensory cell bodies with the longest axons are the most at risk of being injured by paclitaxel (size and length dependent pathology). These results provide a pathological basis for the anatomical distribution of paclitaxel-induced symptoms in patients receiving therapeutic regimens of paclitaxel.
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Neuroscience letters · Sep 2006
Selective migration and engraftment of bone marrow mesenchymal stem cells in rat lumbar dorsal root ganglia after sciatic nerve constriction.
Bone marrow mesenchymal stem cells (MSCs) preferentially migrate to the injured hemisphere when administered intravenously to rats with traumatic or ischemic brain injuries. In this study, we have investigated the localization of MSCs injected into the lumbar-4 dorsal root ganglion (L4-DRG) of rats with a sciatic nerve single ligature nerve constriction (SLNC). MSCs were isolated by their adherence to plastic, cultured until confluence and labelled with Hoechst. ⋯ In animals with a bilateral lesion, MSCs migrated to both the ipsilateral and contralateral DRGs whereas in animals with a contralateral ligature, MSCs migrated to the contralateral DRGs. These results suggest that MSCs preferentially engraft in DRGs hosting primary sensory neurons affected by a lesion of their peripheral branches. Further studies should be carried out in order to elucidate the molecular mechanisms involved in this migration and homing, in order to evaluate the possible use of MSCs as a new therapeutic strategy for the treatment of peripheral nerve neuropathies.
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Neuroscience letters · Aug 2006
CSF -neurofilament correlates with outcome after aneurysmal subarachnoid hemorrhage.
Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating event. Following the bleeding, a number of pathophysiological changes and clinical factors determine outcome. Not surprisingly, attempts to predict outcome based on a single factor have failed. ⋯ A significant correlation between CSF-NFL and GOSE was detected at follow up after 1 year. CSF-NFL also correlated with WFNS and NIHSS on the day of the lumbar puncture. CSF-NFL is a biochemical marker of brain damage correlating to neurological status and long-term outcome after aneurysmal subarachnoid hemorrhage.