Complete axon arborization of a single CA3 pyramidal cell in the rat hippocampus, and its relationship with postsynaptic parvalbumin-containing interneurons.

摘要: The complete axon arborization of a single CA3 pyramidal cell has been reconstructed from 32 (60 microns thick) sections the rat hippocampus following in vivo intracellular injection neurobiotin. same were double-immunostained for parvalbumin--a calcium-binding protein selectively present two types GABAergic interneurons, basket and chandelier cells--in order to map boutons contact with dendrites somata these specific subsets interneurons visualized Golgi-like manner. formed 15,295 boutons, 63.8% which stratum oriens, 15.4% pyramidale 20.8% radiatum. Only 2.1% terminals contacted parvalbumin-positive neurons. Most contacts (84.7%), but double or triple (15.3%) also found. majority terminated on (84.1%) cells, less frequently bodies (15.9%). In estimate proportion representing synapses, 16 light microscopically identified between filled targets examined by correlated electron microscopy. Thirteen them found be asymmetrical remaining three cases synapses labelled profiles could not confirmed. We conclude that physiologically effective excitatory connections cells postsynaptic inhibitory neurons are mediated small number contacts, mostly synapse. This results high degree convergence divergence hippocampal networks.