[Morphofunctional types of synapses in the neurosecretory cells of the carp preoptic nucleus].

The ultrastructure of synaptic endings of the neurosecretory cells of the nucleus preopticus was examined in adult Cyprinus carpio L. Two of synpatic endings occur: type I--small agranular vesicles and large granular vesicles, type II--only agranular vesicles. The functioning of the nucleus preopticus neurosecretory cells in Cyprinus carpio L is presumably controlled by the synpatic endings of the adrenergic (synaptic endings of type I) as well as of the cholinergic (synaptic endings of type II) origin. By visual and morphometric methods different kinds of synpatic endings are distinguished among both the types of synapses according to their particular functional states. A quantitative analysis of the correlation of these kinds of synpatic endings allows a suggestion in respect to the state of the synaptic apparatus on the perikaria of neurosecretory cells.