Electron-microscopic immunocytochemistry of neuropeptide Y immunoreactive innervation of vasopressin neurons in the paraventricular nucleus of the rat hypothalamus.
The neuropeptide Y (NPY) immunoreactive synaptic input to neurons containing neurophysin II (NP II), the carrier protein of vasopressin (VP), was observed in the paraventricular nucleus (PVN) of the rat hypothalamus by double-labeling immunocytochemistry combining the preembedding peroxidase-antiperoxidase (PAP) method with the postembedding immunogold staining method at the electron-microscopic level. NPY-like immunoreactivities were detected by the PAP method in the dense granular vesicles (70-100 nm in diameter) in the immunoreactive presynaptic axon terminals. NP II-like immunoreactive large neurosecretory granules labeled with gold particles were found in the neurons receiving synaptic input of the NPY-like immunoreactive terminals. This suggests that NPY may be a neurotransmitter or neuromodulator and that NPY neurons may, through synaptic contacts, regulate the secretion of VP neurons.
Iwai
C
C
Department of Anatomy, Showa University School of Medicine, Tokyo, Japan.
Ochiai
H
H
Nakai
Y
Y
D000818:Animals; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008854:Microscopy, Electron / Q000379:methods; D009474:Neurons / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D009478:Neuropeptide Y / Q000276:immunology / Q000378:metabolism*; D009481:Neurophysins / Q000276:immunology / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D014667:Vasopressins / Q000378:metabolism*
D009478:Neuropeptide Y; D009481:Neurophysins; D014667:Vasopressins