Synaptic relationships between a multipolar stellate cell and a pyramidal neuron in the rat visual cortex. A combined Golgi-electron microscope study.
Two synapsing and impregnated neurons in the rat visual cortex have been examined by a combined Golgi-electron microscope technique in which the Golgi precipitate is replaced by gold particles. One of the neurons is a stellate cell with smooth dendrites and a well impregnated axon, while the other is a layer III pyramidal neuron. Light microscopy showed some boutons from the axonal plexus of the stellate cell closely apposed to the soma and dendrites of the pyramid and it was predicted that synapses were present at these sites. An electron microscopic examination of serial thin sections, in which the profiles of the impregnated neurons are marked by their content of gold particles, showed most of these predicted synapses to exist. Indeed, axon terminals of the stellate cell formed five symmetric synapses with the cell body of the pyramid, one with the apical dendritic shaft and three with basal dendrites. Reasons are given for believing these synapses to be inhibitory. In addition, it was found that one of the axon terminals of the stellate cell synapsed with one of that cell's own dendrites. The significance of this finding is discussed.
D000818:Animals; D001369:Axons / Q000648:ultrastructure; D003712:Dendrites / Q000648:ultrastructure; D008854:Microscopy, Electron; D009474:Neurons / Q000648:ultrastructure*; D009940:Organoids / Q000648:ultrastructure; D051381:Rats; D013194:Staining and Labeling; D013569:Synapses / Q000648:ultrastructure*; D014793:Visual Cortex / Q000648:ultrastructure*