Nacre extract prevents scopolamine-induced memory deficits in rodents

Objective: To investigate whether the extract from the nacreous layer of pearl oysters (nacre extract) improves impairments in memory caused by scopolamine administration in rodents. Methods: Nacre extract was prepared from the inner shell layer of pearl oyster. Effects of nacre extract on scopolamine-induced memory impairment were estimated using novel object recognition test, Y-maze test, and Barnes maze test. Effect of nacre extract on mRNA expressions which are genes associated with memory in the hippocampus was investigated using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis. Results: Administration of nacre extract led to the protection against scopolamine-induced impairments in object recognition, short-term memory, and spatial memory. Treatment with nacre extract reversed the mRNA expression of brain-derived neurotrophic factor (BDNF) and Homer protein homolog 1 (Homer-la) in the hippocampus, which decreased with the treatment of scopolamine. Conclusions: These results suggest that nacre extract has attenuating effects on memory impairments induced by scopolamine through the increase in mRNA expression of BDNF and Homer-1a.

Calcium carbonate supplementation causes memory impairment in mice

Objective: To investigate the influence of calcium carbonate supplementation on cognitive function in mice. Methods: Mice were fed diets containing 1.0% calcium carbonate for 8 weeks, following which they were evaluated for memory function using object recognition, Y-maze, and Barnes maze tests. Next, the expression levels of cAMP response element binding protein (CREB) and phosphorylated CREB, which is involved in the memory process were investigated in both the hippocampus and cerebral cortex using western blotting methods. Results: Mice fed on a diet containing calcium carbonate showed memory impairments in object recognition, Y-maze, and Barnes maze tests with respect to the mice that were on a control diet. Further, mice that were fed a diet containing calcium carbonate and a nimodipine (an L-type calcium channel antagonist), reversed calcium carbonate-induced memory impairments, thus suggesting that excessive entry of calcium in cells may cause memory impairments. A study using western blot revealed that expression of CREB and phosphorylated CREB in hippocampus and cerebral cortex was significantly lower in the calcium carbonate-fed mice than in the control-diet-fed mice. Conclusions: These results suggest that a calcium carbonate diet may cause memory impairment by decreasing CREB expression. This is the first report of calcium carbonate supplementation causing memory impairment. This simple animal model may be useful as a novel cognitive impairment model for drug development.

Nacre extract prevents scopolamine-induced memory deficits in rodents

Objective:To investigate whether the extract from the nacreous layer of pearl oysters (nacre extract) improves impairments in memory caused by scopolamine administration in rodents.Methods:Nacre extract was prepared from the inner shell layer of pearl oyster. Effects of nacre extract on scopolamine-induced memory impairment were estimated using novel object recognition test, Y-maze test, and Barnes maze test. Effect of nacre extract on mRNA expressions which are genes associated with memory in the hippocampus was investigated using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) analysis.Results:Administration of nacre extract led to the protection against scopolamine-induced impairments in object recognition, short-term memory, and spatial memory. Treatment with nacre extract reversed the mRNA expression of brain-derived neurotrophic factor (BDNF) and Homer protein homolog 1 (Homer-la) in the hippocampus, which decreased with the treatment of scopolamine.Conclusions:These results suggest that nacre extract has attenuating effects on memory impairments induced by scopolamine through the increase in mRNA expression of BDNF and Homer-1a.

Calcium carbonate supplementation causes memory impairment in mice

Objective:To investigate the influence of calcium carbonate supplementation on cognitive function in mice.Methods:Mice were fed diets containing 1.0% calcium carbonate for 8 weeks, following which they were evaluated for memory function using object recognition, Y-maze, and Barnes maze tests. Next, the expression levels of cAMP response element binding protein (CREB) and phosphorylated CREB, which is involved in the memory process were investigated in both the hippocampus and cerebral cortex using western blotting methods.Results:Mice fed on a diet containing calcium carbonate showed memory impairments in object recognition, Y-maze, and Barnes maze tests with respect to the mice that were on a control diet. Further, mice that were fed a diet containing calcium carbonate and a nimodipine (an L-type calcium channel antagonist), reversed calcium carbonate-induced memory impairments, thus suggesting that excessive entry of calcium in cells may cause memory impairments. A study using western blot revealed that expression of CREB and phosphorylated CREB in hippocampus and cerebral cortex was significantly lower in the calcium carbonate-fed mice than in the control-diet-fed mice.Conclusions:These results suggest that a calcium carbonate diet may cause memory impairment by decreasing CREB expression. This is the first report of calcium carbonate supplementation causing memory impairment. This simple animal model may be useful as a novel cognitive impairment model for drug development.

Effects of scallop shell extract on scopolamine-induced memory impairment and MK801-induced locomotor activity

OBJECTIVE@#To evaluate the neuroprotective effects of the organic components of scallop shells (scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo (a,d) cyclohepten-5,10-imine (MK801).@*METHODS@#Effect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test, the Morris water maze test, and the open field test.@*RESULTS@#Scallop shell extract significantly reduced scopolamine-induced short-term memory impairment and partially reduced scopolamine-induced spatial memory impairment in the Morris water maze test. Scallop shell extract suppressed scopolamine-induced elevation of acetylcholine esterase activity in the cerebral cortex. Treatment with scallop shell extract reversed the increase in locomotor activity induced by scopolamine. Scallop shell extract also suppressed the increase in locomotor activity induced by MK801.@*CONCLUSIONS@#Our results provide initial evidence that scallop shell extract reduces scopolamine-induced memory impairment and suppresses MK-801-induced hyperlocomotion.

Effects of scallop shell extract on scopolamine-induced memory impairment and MK801-induced locomotor activity

Objective To evaluate the neuroprotective effects of the organic components of scallop shells (scallop shell extract) on memory impairment and locomotor activity induced by scopolamine or 5-methyl-10,11-dihydro-5H-dibenzo (a,d) cyclohepten-5,10-imine (MK801). Methods Effect of the scallop shell extract on memory impairment and locomotor activity was investigated using the Y-maze test, the Morris water maze test, and the open field test. Results Scallop shell extract significantly reduced scopolamine-induced short-term memory impairment and partially reduced scopolamine-induced spatial memory impairment in the Morris water maze test. Scallop shell extract suppressed scopolamine-induced elevation of acetylcholine esterase activity in the cerebral cortex. Treatment with scallop shell extract reversed the increase in locomotor activity induced by scopolamine. Scallop shell extract also suppressed the increase in locomotor activity induced by MK801. Conclusions Our results provide initial evidence that scallop shell extract reduces scopolamine-induced memory impairment and suppresses MK-801-induced hyperlocomotion.