Development and histological characteristics of neurosecretory cells in the cerebral ganglia of Achatina fulica (Bowdich)

Abstract

Study of postembryonic development of neurosecretory cells in the cerebral ganglia of Achatina fulica showed that they first appear in two month-old snails. The cells are located at the periphery of the procerebrum of cerebral ganglion. The number and size of the neurosecretory cells increase with increasing age of snails, reaching a maximum in eight-month-old snails and thereafter remaining constant in nine-to twelve-month-old snails.

Study of the ultrastructure of the cells showed that they each contain a round shaped nucleus with patches of heterochromatin and a conspicuous single large vacuole in the cytoplasm. In addition, electron-dense elementary granules with a mean diameter of 1600 A° are found to be associated with an extensive Golgi complex and rough endoplasmic reticulum.

Key words:

• cerebral ganglia
• Achatina
• neurosecretory cells