title: [Features of the ultrastructural organization of the neuropile of the 1st layer of the cerebral cortex in the cat].
abstract: The ultrastructure of layer 1 in the middle ectosylvian gyrus (field 22) of the cerebral cortex was investigated in cat. It is shown that the basic part of the superficial neuropile under the subpial astrocytic layer is occupied by nerve fibres, their terminals, final branches and spines of dendrites and by the surrounding astrocyte processes. More than 90% of presynaptic terminals contain round synaptic vesicles. Axo-spine and axo-dendritic asymmetrical synapses are the predominant interneuronal contacts. Presynaptic terminals with flattened and pleomorphic synaptic vesicles participate in the formation of all symmetric contacts, composing 6% of the total number of synapses. Large polymorphic protrusions are described which contain vacuoles and invaginate in varicose enlargements of the terminal branches of apical dendrites of pyramidal neurons. These so-called "multivacuolar sacs" are appendages of presynaptic terminals. The identification of synaptic function in relation to the shape of synaptic vesicles is considered.
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000648:ultrastructure; D001369:Axons / Q000648:ultrastructure; D002415:Cats; D002540:Cerebral Cortex / Q000648:ultrastructure*; D003712:Dendrites / Q000648:ultrastructure; D008854:Microscopy, Electron; D013569:Synapses / Q000648:ultrastructure; D013572:Synaptic Vesicles / Q000648:ultrastructure; D014617:Vacuoles / Q000648:ultrastructure
vernacular_title: Osobennosti ul'trastrukturnoĭ organizatsii neĭropilia pervogo sloia kory bol'shikh polushariĭ koshki.