[Show abstract][Hide abstract] ABSTRACT: To investigate the effect of ketamine administration on memory consolidation, p-CREB and c-fos expression in hippocampus of infant rats and the possible mechanism. Ninety-six SD rats of 21 days old were divided into seven groups, Y-maze was used to test the ability of learning and memory for minor rats. p-CREB and c-fos protein expression was tested by immunhistochemistry. The results showed that the memory consolidation rate in normal saline group mice was higher than that in k1a and k7a group (P<0.05). However, normal saline group between k1b and k7b group was not significant difference. The p-CREB and c-fos protein expressing cells of normal saline group were higher than those in passive control group, pseudotraining group, k1a and k7a group (P<0.05). However, there was not significant difference between normal saline group and k1b or k7b group. The c-fos protein expressing cells of pseudotraining group was higher than those in passive control group, however, the p-CREB protein expressing cells was not significant difference. Therefore, administration of ketamine may temporally affect the ability of memory consolidation rate of minor rats through suppressing the expression of p-CREB and c-fos protein in hippocampus.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study is to investigate whether ketamine, a noncompetitive N-methyl-D: -aspartate receptor (NMDAR) antagonist, had an influence on learning and memory in developing mice. Fifty Kunming mice aged 21 days were randomly divided into 5 subgroups (n = 10 for each) to receive intraperitoneal injection of equal volume of saline (S group) or ketamine (25, 50 or 100 mg/kg of body weight/day) for 7 consecutive days, or to be left untreated (C group). A step-down passive avoidance test was performed to evaluate learning and memory in these mice on days 8 and 9. Additionally, the expression of brain-derived neurotrophic factor (BDNF) in the hippocampus was determined. Rats receiving saline or sub-anesthetic dose of ketamine (25 mg/kg) showed significantly decreased abilities of learning and memory and reduced expression of BDNF, compared to the normal controls (P < 0.05). In contrast, comparable abilities of learning and memory and expression of BDNF were found for anesthetic doses of ketamine (50 or 100 mg/kg)-treated rats and controls (P > 0.05). Repetitive mechanical stress impairs learning and memory performance in developing mice, which may be associated with decreased BDNF expression. The stress-induced learning and memory impairment can be prevented by anesthetic doses of ketamine.
[Show abstract][Hide abstract] ABSTRACT: The plasticity of the central nervous system helps form the basis for the neurobiology of learning and memory. Long-term potentiation (LTP) is the main form of synaptic plasticity, reflecting the activity level of the synaptic information storage process, and provides a good model to study the underlying mechanisms of learning and memory. The glutamate receptor-mediated signal pathway plays a key role in the induction and maintenance of LTP, and hence the regulation of learning and memory. The progress in the understanding of the glutamate receptors and related signal transduction systems in learning and memory research are reviewed in this article.
[Show abstract][Hide abstract] ABSTRACT: The extracellular signal-regulated kinase (ERK) pathway is a member of the mitogen-activated protein kinase (MAPK) superfamily, which is an important, highly conserved family of enzymes associated with cell membrane receptors and regulative targets. In the central nervous system, there is almost no mature neuronal proliferation and differentiation, but the regulation of MAPK and its upstream and downstream molecular pathways is still widespread, with the ERK signaling pathway being one of the most actively studied signal transduction pathways. It is activated by a variety of cell growth factors and substances which promote mitotic activity, and transmits extracellular signals from the cell surface to the nucleus, which transmission plays an important role in the process of cell proliferation and differentiation. In recent years, accumulating evidence has shown that the ERK signaling pathway has an important link with the higher functions of learning and memory.
International Journal of Molecular Sciences 01/2010; 11(1):222-32. DOI:10.3390/ijms11010222 · 2.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To study the effects of ketamine on ERK expression in hippocampal neural cell and the ability of learning behavior in minor rats. Seventy-two Sprague-Dawley rats of 21 days old were randomly divided into nine groups. The Y-maze was used to test the ability of learning and spatial localization. At the end of training, all rats were killed and the expression levels of ERK1, ERK2 and p-ERK1/2 were tested by immunohistochemistry. The learning times and total reaction time (TRT) of group K2a, K2b, K2c and K3 have significant differences compared with T group (P < 0.05). Immunohistochemical staining showed that the level of ERK1, ERK2 and p-ERK1/2 in all rats which received light-electricity integrated training increased remarkably relative to the C group (P < 0.01). The expression levels of ERK1, ERK2 and p-ERK1/2 in hippocampal neural cell of group K2a, K2b and K3 significantly decreased when compared with T group (P < 0.05). Therefore, the results demonstrate that administration of over-anesthetic ketamine may impair learning ability of 21 days old rats within 24 h. ERK signal transduction pathway may be involved in the ability of learning and spatial localization. The inhibition of ERK signal transduction pathway may be one of the mechanisms of the impairment of learning and memory ability by ketamine.