neurosecretory vesicle
Specialized organelles in neuroendocrine cells that store and release hormones and neuropeptides.
Full Definition
Neurosecretory vesicles are membrane-bound organelles found in neuroendocrine cells that serve as storage and release sites for hormones, neuropeptides, and neurotransmitters. These vesicles are formed at the trans-Golgi network and undergo maturation as they move toward the cell periphery, concentrating their peptide contents and acquiring the molecular machinery necessary for regulated exocytosis. Two main types exist: large dense-core vesicles (100-300 nm) that store peptide hormones and neuropeptides, and smaller synaptic vesicles (40-60 nm) that contain classical neurotransmitters. Upon appropriate stimulation, these vesicles fuse with the plasma membrane through calcium-dependent exocytosis, releasing their contents into synapses or the circulation. The vesicles contain characteristic proteins like chromogranins, synaptophysin, and various processing enzymes that serve as diagnostic markers for neuroendocrine cells.
Usage
Usage note: Specify vesicle type (dense-core vs. synaptic) when precision is required; dense-core vesicles are more relevant to neuroendocrine function.
In Context
- "Electron microscopy revealed abundant neurosecretory vesicles within the hypothalamic neuron terminals." — Neuroanatomy research paper
- "The tumor cells showed immunoreactivity for synaptophysin, confirming the presence of neurosecretory vesicles." — Histopathology report