Neuroscience letters
-
Neuroscience letters · Oct 2007
Can variation in aquaporin 4 gene be associated with different outcomes in traumatic brain edema?
In traumatic brain injury (TBI), cerebral edema and hemorrhage are factors involved in the determination of the clinical presentation and outcome. The aquaporin 4 (AQP4) water channel is abundant in mammalian brain and there is a growing body of evidence suggesting that this protein plays a major role in the control of water flow within the central nervous system. Previous studies examined the influence of genetic variants in cerebral edema of TBI. ⋯ We did not find any variation in exon 4 of the AQP4 gene in our considerable large sample. Despite this negative result, there is a strong biological rationale for the involvement of AQP4 gene in brain edema regulation and, as consequence, in TBI. Therefore, further studies should be performed, including the assessment of the other three exons of the AQP4 gene.
-
Neuroscience letters · Oct 2007
Effect of different patterns of low-frequency stimulation on piriform cortex kindled seizures.
Low-frequency stimulation (LFS) is an antiepileptic and antiepileptogenic electrical stimulation. In this study the effect of changes in some LFS (1Hz, monophasic square wave) parameters (intensity, pulse duration and train duration) on piriform cortex kindled seizures was investigated both in fully kindled rats and during kindling acquisition. In fully kindled animals, application of different patterns of LFS immediately before kindling stimulation had no significant effect on seizure parameters. ⋯ According to obtained results, it may be concluded that in fully kindled rats application of different patterns of LFS before kindling stimulation has no anticonvulsant effect, but it can exert an inhibitory effect when applied during an inter-seizure interval of 7 days. In addition, LFS has antiepileptogenic effect during kindling acquisition. These effects depend on the applied LFS parameters (e.g. intensity, pulse duration and train duration).
-
Neuroscience letters · Oct 2007
Inhibitory effect on cerebral inflammatory agents that accompany traumatic brain injury in a rat model: a potential neuroprotective mechanism of recombinant human erythropoietin (rhEPO).
Erythropoietin (EPO) has recently been shown to have a neuroprotective effect in animal models of traumatic brain injury (TBI). However, the precise mechanisms remain unclear. Cerebral inflammation plays an important role in the pathogenesis of secondary brain injury after TBI. ⋯ Measures of IL-6 showed no change after rhEPO treatment. Administration of rhEPO reduced brain edema, BBB permeability and apoptotic cells in the injured brain. In conclusion, post-TBI rhEPO administration may attenuate inflammatory response in the injured rat brain, and this may be one mechanism by which rhEPO improves outcome following TBI.
-
Neuroscience letters · Oct 2007
Delayed hyperbaric oxygenation is more effective than early prolonged normobaric hyperoxia in experimental focal cerebral ischemia.
Hyperbaric (HBO) and normobaric (NBO) oxygen therapy have been shown to be neuroprotective in focal cerebral ischemia. In previous comparative studies, NBO appeared to be less effective than HBO. However, the experimental protocols did not account for important advantages of NBO in the clinical setting such as earlier initiation and prolonged administration. ⋯ Neurological deficit was significantly smaller in HBO treated animals (Garcia score: 13.3+/-1.2) than in animals treated with air (12.1+/-1.4), but did not differ significantly from NBO (12.4+/-0.9) and NBO+HBO (12.8+/-1.1). In conclusion, HBO is a more effective therapy than NBO in transient experimental ischemia even when accounting for delayed treatment-onset of HBO. The combination of NBO and HBO results in no additional benefit.
-
Neuroscience letters · Sep 2007
Long-range projections of Adelta primary afferents in the Lissauer tract of the rat.
Electrical microstimulation has been used to activate fine myelinated primary afferents running within the Lissauer tract. Stimulation of the tract at the L2/L3 border produced antidromic volleys which were recorded on the dorsal roots of more caudal spinal segments. Antidromic volleys were present in all cases for roots as far caudal as the S2 segment (L3, n=12; L4, n=6; L5, n=6; L6, n=9; S1, n=3; S2, n=6; observations in a total of 15 rats). ⋯ Lesions of the Lissauer tract caudal to the stimulation site abolished the volleys on roots lying caudal to the lesion. Most previous works have suggested that primary afferents project in the Lissauer tract for only one or two spinal segments. The present study shows that some fibres project rostrally for up to seven spinal segments (L2-S2).