Experimental neurology
-
Experimental neurology · Sep 2003
Inhibitory effect of intrathecal glycine on the micturition reflex in normal and spinal cord injury rats.
We examined the influence of lumbosacral glycinergic neurons on the spinobulbospinal and spinal micturition reflexes. Female rats were divided into intact rats, rats with acute injury to the lower thoracic spinal cord (SCI), and rats with chronic SCI. Under urethane anesthesia, isovolumetric cystometry was performed in each group before and after intrathecal (IT) injection of glycine or strychnine into the lumbosacral cord level. ⋯ On amino acid analysis, IT glycine (0.01-100 microg) decreased the glutamate level of the lumbosacral cord in intact rats, but not in chronic SCI rats. The glycine level of the lumbosacral cord was 54% lower in chronic SCI rats when compared with intact rats, while the GlyR alpha1 mRNA level did not change after SCI. These results suggest that glycinergic neurons may have an important inhibitory effect on the spinobulbospinal and spinal micturition reflexes at the level of the lumbosacral cord.
-
Experimental neurology · Sep 2003
Clinical Trial Controlled Clinical TrialSubstance-P-induced protein extravasation is bilaterally increased in complex regional pain syndrome.
Pain, mechanical hyperalgesia, edema, increased skin temperature, and skin reddening are characteristic symptoms of acute complex regional pain syndrome (CRPS). We have recently demonstrated facilitated neurogenic inflammation on the affected limb. To further elucidate the underlying mechanisms, exogenous substance P (SP) in ascending concentrations (10(-9), 10(-8), 10(-7), 10(-6) M) was intradermally applied to the affected and the unaffected limbs, respectively, in two groups of 11 CRPS patients each using the microdialysis technique. ⋯ We conclude that SP-induced plasma protein extravasation is increased in CRPS patients on both the affected and unaffected limbs. The underlying mechanism might be impaired SP inactivation. Thus, our results further support the hypothesis that neurogenic inflammation plays an important role in the initiation of CRPS.
-
Experimental neurology · Sep 2003
Increased expression and localization of the RNA-binding protein HuD and GAP-43 mRNA to cytoplasmic granules in DRG neurons during nerve regeneration.
The neuronal-specific RNA-binding protein, HuD, binds to a U-rich regulatory element of the 3' untranslated region (3' UTR) of the GAP-43 mRNA and delays the onset of its degradation. We have recently shown that overexpression of HuD in embryonic rat cortical cells accelerated the time course of normal neurite outgrowth and resulted in a twofold increase in GAP-43 mRNA levels. Given this evidence, we sought to investigate the involvement of HuD during nerve regeneration. ⋯ Not only were the temporal patterns of expression of HuD protein and GAP-43 mRNA similar, but also they were found to colocalize in the cytoplasm of DRG neurons. Moreover, both molecules were distributed in cytoplasmic granules containing ribosomal RNA. In conclusion, our results suggest that HuD is involved in the upregulation of GAP-43 expression observed at early stages of peripheral nerve regeneration.
-
Experimental neurology · Sep 2003
Multicenter Study Clinical TrialMeasurement of alpha- and beta-secretase cleaved amyloid precursor protein in cerebrospinal fluid from Alzheimer patients.
One of the major histopathological hallmarks of Alzheimer's disease (AD) is redundant senile plaques mainly composed of beta-amyloid (Abeta) aggregates. Alternative cleavage of the amyloid precursor protein (APP), occurring in both normal and AD subjects, results in the generation and secretion of soluble APP (sAPP) and Abeta. We examined the cerebrospinal fluid (CSF) for alpha- and beta-secretase cleaved sAPP (alpha-sAPP and beta-sAPP) in 81 sporadic AD patients, 19 patients with mild cognitive impairment, and 42 healthy controls by using newly developed sandwich enzyme-linked immunosorbent assay methods. ⋯ We also investigated the relationship between the CSF level of alpha/beta-sAPP and Abeta(42) and the apoE epsilon 4 (apoE4) allele. Significantly lower levels of CSF-alpha-sAPP were found in AD patients possessing one or two apoE4 alleles than in those not possessing the apoE4 allele. Neither the levels of CSF-beta-sAPP nor CSF-Abeta(42) differed when comparing ApoE4 allele-positive with allele-negative individuals.