Hippocampus Thomas Henry Huxley and Richard Owen, satirised as the Great Hippocampus Question. The term hippocampus minor fell from use in anatomy textbooks, and was officially removed in the Nomina Anatomica of 1895. Today, the structure is just called the hippocampus, with the term "Cornu Ammonis" surviving in the names of the hippocampal subfields CA1-CA4. The term "limbic system" was introduced in 1952 by Paul MacLean to describe the set of structures that line the edge of the cortex (Latin "limbus" meaning "border"): These include the hippocampus, cingulate cortex, olfactory cortex, and amygdala. Paul MacLean later suggested that the limbic structures
Epigenetics in learning and memory G9a/GLP in the EC, but not in the hippocampus, results in the enhancement of long-term memory formation. In addition, G9a/GLP inhibition in the entorhinal cortex altered histone H3 lysine 9 dimethylation in the Cornu Ammonis area 1 of the hippocampus, suggesting the importance of this complex in mediating connectivity between these two brain regions. Therefore, the G9a/GLP complex plays an important role in histone methylation and long term memory formation in the hippocampus and the EC. Histone methylation marks are also correlated with other epigenetic modifications, such as histone deacetylation and DNA methylation, in the context of learning and memory.