Background: Long-term memory is based on synaptic plasticity, a series of biochemical mechanisms include changes in structure and proteins of brain's neurons. In this article, we systematically reviewed the studies that indicate calcium/calmodulin kinase II (CaMKII) is a ubiquitous molecule among different enzymes involved in human long-term memory and the main downstream signaling pathway of long-term memory. Methods: All of the observational, case-control and review studies were considered and evaluated by the search engines PubMed, Cochrane Central Register of Controlled Trials and ScienceDirect Scopus between 1990 and February 2015. We did not carry out meta-analysis. Results: At the first search, it was fined 1015 articles which included "synaptic plasticity" OR "neuronal plasticity" OR "synaptic density" AND memory AND "molecular mechanism" AND "calcium/calmodulin-dependent protein kinase II" OR CaMKII as the keywords. A total of 335 articles were duplicates in the databases and eliminated. A total of 680 title articles were evaluated. Finally, 40 articles were selected as reference. Conclusions: The studies have shown the most important intracellular signal of long-term memory is calcium-dependent signals. Calcium linked calmodulin can activate CaMKII. After receiving information for learning and memory, CaMKII is activated by Glutamate, the most important neurotransmitter for memory-related plasticity. Glutamate activates CaMKII and it plays some important roles in synaptic plasticity modification and long-term memory.

Background: The etiology of attention deficit hyperactivity disorder (ADHD) is not exactly known and its etiology is multifactorial. The usual treatment for these children is based on pharmacotherapy treatment, although the pharmacotherapy has a high effectiveness in ADHD treatment, it often causes different side effects. Existing evidence suggests that children who receive mineral supplement without considering their age and supplement formula may perform better on different behavioral tests compared with those receiving placebo. Methods: In this study, we tried to review the previous evidence regarding the effects of minerals in prevention and management of ADHD. We searched PubMed/Medline, Google Scholar, Ovid, Scopus, and ISI web of science up to June 2013. "iron," "iron supplementation," "magnesium," "magnesium supplementation," "zinc," "zinc supplementation," "attention deficit hyperactivity disorder" were used as the keywords. Totally 11 randomized controlled trials were eligible to be included in the systematic review. Results: Our review showed that we don't have any predominant evidence about using mineral supplementation on children with ADHD. Conclusions: We need more evidence for indicating the effect of zinc, magnesium, and iron supplementation in the treatment of ADHD among children.