[Small granule-containing cells of the central nervous system of the bivalve mollusk Patinopectin yessoensis (Jay)].

In the CNS of the Patinopecten yessoensis (Jay) two types of cells have been revealed. The I type cells are typical unipolar neurons with a developed granular endoplasmic reticulum and Golgi compex, with a nucleus containing small amount of chromatin. They possess elementary peptidergic granules. The II type cells have in their cytoplasm and processes a large amount of electron-opague granules, specific for adrenergic systems. The nucleus is rich in clustered chromatin, the granular endoplasmic reticulum is poorly developed, cytosomes are absent. According to their ultrastructural organization the latter correspond to small granular cells of the mammalian autonomic nervous system.