myelin-basic-protein and Constriction--Pathologic

Gabapentin (GBP) is an anti-convulsive drug often used as analgesic to control neuropathic pain. This study aimed at evaluating oral GBP treatment (30, 60, 120 mg/kg, 60 min prior to chronic constriction of the sciatic nerve (CCSN) along 15-day treatment post-injury, 12 h/12 h) by monitoring spontaneous and induced-pain behaviors in Wistar rats on 5th and 15th days post-injury during early neuropathic events. CCSN animals receiving saline were used as controls. Another aim of this study was to evaluate GBP effects on myelin basic protein (MBP) on the 5th and 15th days post-injury and nerve morphology by transmission electron microscopy to address nerve regeneration. On the 5th and 15th days, GBP (60 mg/kg) reduced neuropathic pain behaviors (scratching and biting) in the ipsilateral paw and alleviated mechanical allodynia in comparison with the neuropathic saline group. GBP significantly increased climbing and rearing behaviors in CCSN and CCSN-free animals suggesting increased motor activity rather than sedation. We found three-fold significant increase in MBP expression by western blots on the 15th day when compared to controls. In addition, GPB (60 mg/kg) improved nerve axonal, fiber and myelin area 15 days post-surgery. In conclusion, GBP alleviated mechanical and thermal allodynia and spontaneous pain-related behaviors and improved later nerve morphology. Our findings suggest that GBP improve nerve remyelination after chronic constriction of the sciatic nerve.

Topics: Amines; Animals; Anticonvulsants; Constriction, Pathologic; Cyclohexanecarboxylic Acids; Gabapentin; gamma-Aminobutyric Acid; Male; Myelin Basic Protein; Nerve Regeneration; Neuralgia; Rats, Wistar; Sciatic Nerve

Neuropathological and immunohistochemical studies were done on the brain-stem of neonates who had congenital hydrocephalus with aqueductal stenosis or Arnold-Chiari malformation (ACM). The infants with aqueductal stenosis showed heterogeneity in their clinicopathological findings while the infants with ACM were relatively similar in neuropathological findings. There were prominent astrogliosis, decreased immunoreactivity with antisera to tyrosine hydroxylase and myelin basic protein in the periaqueductal area, and an increased reactivity with antiserum to substance P in the tegmentum of most patients with aqueductal stenosis and other malformations. In ACM, there was little gliosis in the tegmentum and periaqueductal area and minimal immunoreactivity of tyrosine hydroxylase, myelin basic protein and substance P. In both groups of cases, the cells in the periaqueductal region differ in neurotransmitter/neuromodulator immunoreactivity and degree of myelination reflecting a difference possibly in their maldevelopment.

Topics: Arnold-Chiari Malformation; Brain Stem; Cerebral Aqueduct; Constriction, Pathologic; Glial Fibrillary Acidic Protein; Humans; Hydrocephalus; Immunohistochemistry; Infant, Newborn; Myelin Basic Protein; Substance P; Tyrosine 3-Monooxygenase