In his presentation on octpus consciousness at the Alan Turing Summer Institute on consciousness, David Edelman (son of Nobel Laureate Gerald Edelman) briefly referred to a paper by David Glanzman, showing a figure on synaptic plasticity that was merged from the three figures in David Glanzman's paper. I've reproduced this merged figure below, because I intend to use it in my lectures and I missed a figure like this one so far. It shows the transition towards a modern model of synaptic plasticity, with the topmost panel showing the 'invertebrate' presynaptic plasticity and then the 'vertebrate' postsynaptic plasticity as separate as they wre conceived up until about 1995. The final, lowermost panel shows the combined picture as both in invertebrates and in vertebrates there is sufficient evidence today pointing to both pre- and postsynaptic plasticity in all brains studied in enough detail so far:



This figure is a fusion of Figs. 1-3 from the Current Biology paper by David Glanzman linked to above.