title: Concentration of F-actin in synaptic formations of the hippocampus as visualized by staining with fluorescent phalloidin.
abstract: Polymerized actin (F-actin) was localized in the guinea pig hippocampus by fluorescent staining with rhodamine-labeled phalloidin. Phalloidin displayed a preferential affinity for the main synaptic areas where the fluorescence was confined to 0.5-1 micron particles, roughly the size of synaptic structures (dendritic spines and presynaptic terminals). These particles appeared to stud the surface of dendrites. Particularly large and strongly fluorescent particles mainly 1-3 micron in diameter were found in the termination zone of mossy fibres which form the largest synapses of the hippocampus. The apparent high concentration of F-actin in synaptic formations suggests a role for actin in synaptic function.
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D006168:Guinea Pigs; D006624:Hippocampus / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D010590:Phalloidine; D013194:Staining and Labeling / Q000379:methods; D013569:Synapses / Q000378:metabolism
chemical_list: D000199:Actins; D010590:Phalloidine