Aged, 80 and over ; Antiparkinson Agents ; pharmacology ; therapeutic use ; Female ; Humans ; Lewy Body Disease ; drug therapy ; psychology ; Memantine ; adverse effects ; pharmacology ; therapeutic use ; United States

OBJECTIVETo evaluate the effects of glial cell line-derived neurotrophic factor (GDNF) and memantine on the long-term prognosis in neonatal rats with ischemia-induced periventricular leukomalacia (PVL).

METHODSThirty-two 5-day-old neonatal rats were randomly divided into 4 groups: sham-operated, PVL, GDNF-treated and memantine-treated. PVL was induced by right carotid artery ligation and hypoxia in the PVL, GDNF-treated and memantine-treated groups. GDNF (100 μg/kg) or memantine (20 mg/kg) was injected in the two treatment groups immediately after PVL inducement. The weight of the rats was measured immediately before and after hypoxia ischemia (HI). Both of Morris water maze test and Rivlin inclined plane test were performed at 26 days old (21 days after HI). The values of the escape latency (EL) and swimming distance, and the maximum inclined plane degree which the rats could stand at least 5 seconds were compared among the four groups.

RESULTSThe lower weight, the prolonged mean values of EL and swimming distance and the reduced maximum inclined plane degree were observed in the PVL group compared to those in the sham-operated, GDNF-treated and memantine-treated groups. There were no significant differences in the weight, the values of EI and swimming distance and the maximum inclined plane degree between the two treatment groups and the sham-operated group.

CONCLUSIONSThe administration of either GDNF or memantine can markedly increase the abilities of spatial discrimination,learning and memory, and motor coordination, promote weight gain, and improve long-term prognosis in rats with PVL.

Animals ; Animals, Newborn ; Body Weight ; Excitatory Amino Acid Antagonists ; therapeutic use ; Glial Cell Line-Derived Neurotrophic Factor ; therapeutic use ; Humans ; Infant, Newborn ; Leukomalacia, Periventricular ; drug therapy ; psychology ; Maze Learning ; drug effects ; Memantine ; therapeutic use ; Motor Activity ; drug effects ; Rats

Animals ; Animals, Newborn ; Drugs, Chinese Herbal ; therapeutic use ; Excitatory Amino Acid Antagonists ; therapeutic use ; Hypoxia-Ischemia, Brain ; metabolism ; prevention & control ; Memantine ; therapeutic use ; Platelet Activating Factor ; analysis ; Rats ; Rats, Sprague-Dawley

OBJECTIVEAnimal trials have demonstrated that memantine has neuroprotective effects on hypoxic-ischemic (HI) brain damage. Whether memantine can improve the long-term prognosis of rats with HI brain damage has not been reported. This study was designed to investigate the long-term effect of memantine therapy on neonatal rats with HI brain damage.

METHODSSixty postnatal 7-day-old newborn rats were randomly assigned into Normal control, HI and Memantine treated groups. Memantine (20 mg/kg) was administered immediately after HI in the Memantine-treated group. All subjects received a 5-day training of Morris water maze test from 23 days old. The escape latency (EL) was recorded at 28 and 35 days old.

RESULTSThe EL values of the Normal control, HI and Memantine-treated groups at 28 days old were 23.1 +/- 21.8, 35.1 +/- 5.3, and 20.6 +/- 3.4 seconds, respectively. There was a significant difference in the EL value between the HI and the Normal control groups (P < 0.05). The EL value of the Normal control, HI and Memantine-treated groups at 35 days old were 19.7 +/- 16.7, 35.6 +/- 32.3, and 16.3 +/- 13.2 seconds, respectively. A prolonged EL induced by HI still existed (P < 0.05 vs Normal controls) but memantine treatment shortened the EL (P < 0.01 vs HI group) at 35 days old.

CONCLUSIONSAdministering memantine immediately after HI can markedly increase the abilities of spatial discrimination, learning and memory and improve the long-term prognosis in rats with HI brain damage.

Animals ; Animals, Newborn ; Avoidance Learning ; drug effects ; Brain ; metabolism ; Excitatory Amino Acid Antagonists ; therapeutic use ; Female ; HSP70 Heat-Shock Proteins ; genetics ; Hypoxia-Ischemia, Brain ; drug therapy ; metabolism ; psychology ; Male ; Maze Learning ; drug effects ; Memantine ; therapeutic use ; Rats ; Rats, Sprague-Dawley

Activities of Daily Living ; Alzheimer Disease ; diagnosis ; drug therapy ; psychology ; therapy ; Caregivers ; psychology ; Cholinesterase Inhibitors ; therapeutic use ; Clinical Trials as Topic ; Cognition ; Endpoint Determination ; Humans ; Memantine ; therapeutic use ; Neuropsychological Tests ; Patient-Centered Care ; Quality of Life ; Singapore ; Stress, Psychological ; prevention & control ; Treatment Outcome

OBJECTIVETo evaluate pathologically the effect of the single or combined application of UDP-glucose, GDNF and memantine on the improvement of white matter injury in neonatal rats with periventricular leukomalacia (PVL) under light and electron microscopy.

METHODSA five-day-old neonatal rat model for PVL was established by ligation of the lateral common carotid artery following 120-minute hypoxia. Rats were randomly divided into six groups (30 rats in each group): sham-operated, PVL, UDP-glucose (UDP-glucose 2000 mg/kg intraperitoneally after PVL), GDNF (GDNF 100 μg/kg intracerebrally after PVL), tmemantine (memantine 20 mg/kg intraperitoneally after PVL), and a combination administration of three drugs (UDP-glucose, GDNF and memantine). The rats were sacrificed 7 or 21 days after PVL for assessment of pathological changes in the white matter under both light and electron microscopy. The number and thickness of the myelin sheath in the white matter were measured under electron microscopy, and both of pathological grading and scoring were undertaken under light microscopy.

RESULTSThere was rare and sparse myelinogenesis with a loose arrangement of nerve fibers in the white matter under electron microscopy in the PVL group at 7 and 21 days after PVL. The number and thickness of the myelin sheath in the PVL group were significantly less than in the sham-operated, UDP-glucose, GDNF, memantine and combination administration groups (P<0.01). The results of pathological grading of white matter under light microscopy showed that all rats in the PVL group manifested either mild injury (38%-50%) or severe injury (50%-62%) at 7 and 21 days after PVL. The majority of rats (50%-88%) in the four drug administration groups had normal white matter at 7 and 21 days after PVL. The pathological scores at 7 and 21 days after PVL in the PVL group were the highest, and they were significantly higher than in the other five groups (P<0.05).

CONCLUSIONSThe single or combined application of UDP-glucose, GDNF and memantine may significantly improve pathological changes in the white matter of rats with PVL. The favorable effect is inferred to be closely correlated with the improvement of brain microenvironment and the enhancement of nerve regeneration promoted by the three drugs.

Animals ; Brain Ischemia ; drug therapy ; pathology ; Cerebral Ventricles ; pathology ; ultrastructure ; Female ; Glial Cell Line-Derived Neurotrophic Factor ; administration & dosage ; therapeutic use ; Humans ; Infant, Newborn ; Leukomalacia, Periventricular ; drug therapy ; Male ; Memantine ; administration & dosage ; therapeutic use ; Microscopy, Electron ; Rats ; Rats, Sprague-Dawley ; Uridine Diphosphate Glucose ; administration & dosage ; therapeutic use

The purpose of this study was to evaluate the neuroprotective effect of memantine, a N-methyl-D-aspartate antagonist, in an experimental optic nerve ischemia. Endothelin-1 (ET-1) in a dosage of 0.1 microg/day was delivered to the perineural region of the anterior optic nerve by osmotically driven minipumps for 8 weeks in 10 rabbits. In 5 rabbits, 1 mg/kg memantine was administered concurrently by intramuscular injection once a daily. Morphologic optic nerve head changes were monitored with a confocal scanning laser ophthalmoscope. Multivariate statistical analysis showed a significant change in topometric parameters (cup area, cup depth and rim volume), indicating an increase in optic nerve head cupping and a decrease of neural rim volume in the ET-1 administered eyes (P < 0.0001). In rabbits where memantine was given concurrently with ET-1, no significant change in topometric parameters was observed after ET-1 administration (P = 0.78). The current results suggest that memantine has a neuroprotective effect in optic nerve ischemia. Memantine may potentially be useful in the management of various ischemic disorders of the optic nerve, including glaucoma.
Animal ; Comparative Study ; Endothelin-1/toxicity ; Excitatory Amino Acid Antagonists/*therapeutic use ; Male ; Memantine/*therapeutic use ; Models, Animal ; Neuroprotective Agents/*therapeutic use ; Optic Disk/*drug effects/pathology ; Optic Nerve/*drug effects/pathology ; Optic Neuropathy, Ischemic/chemically induced/pathology/*prevention & control ; Rabbits