Portal de Periódicos da CAPES

Neurosecretory cells in the cerebral ganglion of adult tunicates: Fine structure and distribution of phosphatases

1972; Academic Press; Volume: 40; Issue: 5-6 Linguagem: Inglês

10.1016/s0022-5320(72)80037-6

1878-2345

Nancy J. Lane,

Marine Invertebrate Physiology and Ecology

The adult tunicates Ciona, Styela, and Botryllus possess a single cerebral ganglion which consists of a cortex of nerve cells surrounding a central neuropile; no glial investment of the neurons is apparent. The ganglia contain a number of neurosecretory cells which have prominent Golgi complexes, seemingly involved in the elaboration of neurosecretory granules by terminal budding. Various types of dense bodies are also present and, as these display reaction product after incubation for acid phosphatase, they are considered to represent lysosomes—unlike vertebrate lysosomes, some of them also contain thiamine pyrophosphatase activity. Certain saccules and vesicles of the Golgi complex manifest both acid phosphatase and thiamine pyrophosphatase activities as well. However, although the Golgi membrane around the immature neurosecretory granules may show phosphatase activity, the granules themselves do not. Some cisternae of the endoplasmic reticulum also contain reaction product for thiamine pyrophosphatase. The fine structural and cytochemical features of these ascidian cells are considered with respect to the intermediate phylogenetic position of these organisms.