Efecto de la masticación sobre la memoria y aprendizaje espacial en ratones adultos y seniles / Effect of chewing on memory and spatial learning in adult and senile mice

Resumen Introducción: La masticación es una actividad periférica que influye positivamente sobre el sistema nervioso central (SNC). Sin embargo, a pesar de los diferentes estudios realizados, aún no está claro cómo la masticación afecta a los procesos cognitivos. Debido a ello se buscó determinar el efecto de la masticación sobre la memoria y aprendizaje espacial en ratones adultos y seniles. Materiales: Se empleó un grupo de 16 ratones adultos y de 16 ratones seniles que fueron aleatorizados en 2 subgrupos de 8 ratones cada uno. Un subgrupo se alimentó con dieta granosa convencional para ratón (subgrupo masticación normal), el otro subgrupo se alimentó con dieta en polvo (subgrupo masticación deficiente). Durante 2 meses se sometió a cada subgrupo a su dieta respectiva. Se evaluó en el laberinto acuático de Morris a los ratones adultos a los 7 meses de edad y a los seniles a los 12 meses de edad, mediante la fase de adquisición y de fase de recuperación de memoria y aprendizaje espacial. Resultados: Los ratones adultos, con masticación normal, mostraron mejor adquisición de memoria y aprendizaje espacial con respecto a los ratones con masticación deficiente en el primer día de evaluación (p = 0,035). Al agrupar a los ratones bajo el mismo tipo de masticación se encontró, en los subgrupos bajo masticación normal, una mejor adquisición de memoria y aprendizaje espacial en el subgrupo adulto sobre el subgrupo senil (p < 0,05). Conclusiones: La masticación normal tuvo un efecto positivo sobre la adquisición de información espacial en los ratones adultos.

Introduction: Chewing is a peripheral activity that positively influences the central nervous system (CNS). However, despite the different studies carried out, it is still not clear how chewing affects cognitive processes. Because of this, was trying to find the effect of chewing on memory and spatial learning in adult and senile mice. Methods: A group of 16 adult and senile mice were randomized into 2 subgroups of 8 mice each group. One subgroup was fed with conventional grainy diet for mice (normal chewing subgroup), the other subgroup was fed dietary powder (deficient chewing subgroup). During 2 months each subgroup was submitted to their respective diet. Adult mice at 7 months of age and senile at 12 months of age were evaluated in the Morris' water maze; through of the acquisition phase and the probe test of memory and spatial learning. Results: Adult mice with normal chewing showed better memory acquisition and spatial learning with respect to mice with deficient chewing on the first day of evaluation (p = 0.035). When grouping the mice in the same type of chewing, in the subgroups under normal chewing, a better acquisition of memory and spatial learning was found in the adult subgroup on than in the senile subgroup (p < 0.05). Conclusions: Normal chewing had a positive effect on the acquisition of spatial information in adult mice.

Effects of Siwu Decoction on Memory and Spatial Learning in Mice with Blood Deficiency and Related Mechanisms / 医药导报

Objective To investigate the effects of Siwu decoction on the learning and memory abilities in mice with blood deficiency and the related mechanism.Methods The mice were randomly divided into five groups:normal control group,model control group,high-,medium-,and low-dose group of Siwu decoction.Blood deficiency mouse model was established by continuously cuttingtailand bleedingin model control group,high-,medium-,and low-dose group of Siwu decoction.The mice in high-,medium-,and low-dose group were intragastrically administrated with Siwu decoction of 2.5,5.0,10.0 g·kg-1 for 14 days,respectively.The erythrocyte counts (RBC),hemoglobin (HGB),red blood cell hematocrit (HCT) were detected before modeling,7 and 14 days after administration.The spatial learning and memory abilities were assessed using the T maze test.The spontaneous activities were assessed using locomotors activity detector.The levels of erythropoietin (EPO) content in serum and acetylcholinesterase (AChE) in hippocampal tissue were detected by enzyme-linked immunousorbent assay.Results 5.0 and 10.0 g·kg-1Siwu decoction could increase RBC,HGB,HCT on the 7th and 14th day,2.5 g.kg-1Siwu decoction could increase RBC,HCT on 14th day,and each dosage of Siwu decoction could significantly increase the spontaneous activities of model mice with blood deficiency on the 7th and 14th day as compared with model control group (P ＜0.05 or P ＜0.01).Compared with model control group,the number of errorsin T Maze test were decreased significantly in high-,medium-,and low-dose groups (P ＜ 0.01).And the Siwu decoction had a tendency to reduce the hippocampal AChE levels,but when compared with the model control group there were no statistical differences (P ＞ 0.05).Conclusion Siwu decoction is benefit formemory and spatial learning in mice with blood deficiency,which may be related with higher serun EPO and lower hippocampal AChE expression.