Aplysia and Learning

Professor Eric Kandel discusses the attributes that make Aplysia, a type of sea slug, an ideal model for studying learning and memory.

I went to Aplysia because I thought it would be a very good model for learning for three reasons. One is, it has a nervous system made up of relatively few cells. Your brain has a million, million nerve cells, Aplysia has twenty thousand nerve cells, number one. Number two, these cells are collected in clusters called ganglia; there are ten of them. Each one has about two hundred nerve cells. Three, the cells are the largest nerve cells in the animal kingdom. You can see them with your naked eye. And they are not only large, they are distinctive, so you can recognize each cell as an individual and return to different cells in every animal of the species, and those prove to be extremely good advantages for studying any behavior and seeing how behavior is modified by learning and memory.