title: Problems of understanding the substructure of synapses.
mesh_terms: D000818:Animals; D008870:Microtubules / Q000648:ultrastructure; D008959:Models, Neurological; D011896:Rana temporaria; D051381:Rats; D013569:Synapses / Q000648:ultrastructure*; D013572:Synaptic Vesicles / Q000378:metabolism / Q000648:ultrastructure