Heterogeneous distribution of neurocalcin-immunoreactive nerve terminals in the mouse adrenal medulla.
Neurocalcin is a novel calcium-binding protein found in bovine brain tissue. We investigated immunoreactivity for neurocalcin in the mouse adrenal medulla using light and electron microscopy. The immunoreactivity was present in nerve fibers, nerve terminals, and ganglion cells in the adrenal medulla, but chromaffin cells, sustentacular cells, and Schwann cells were negative in reaction. Nerve bundles containing neurocalcin-immunoreactive fibers passed through the adrenal cortex and extended into the medulla. Immunopositive nerve fibers branched off and projected varicose terminals around the chromaffin cells. These varicose terminals contained small and large-cored vesicles and made synapses with the chromaffin cells. We performed paraformaldehyde-induced fluorescence-histochemical studies for catecholamine combined with immunohistochemical studies for neurocalcin. Neurocalcin-immunoreactive nerve terminals were more abundant at noradrenaline (fluorescent) cell-rich regions than at adrenaline (non-fluorescent) cell-rich regions. These results show that neurocalcin-immunoreactive nerves mainly innervate noradrenaline-containing chromaffin cells in the mouse adrenal medulla and that neurocalcin may regulate synaptic function in the nerve terminals.
Iino
S
S
Department of Anatomy, Nagoya University School of Medicine, Showa-ku, Nagoya 466, Japan. iinosa@tsuru.med.nagoya-u.ac.jp
Kobayashi
S
S
Hidaka
H
H
D000313:Adrenal Medulla / Q000294:innervation*; D000818:Animals; D002135:Calcium-Binding Proteins / Q000032:analysis / Q000276:immunology*; D005404:Fixatives; D005557:Formaldehyde; D005728:Ganglia, Sympathetic / Q000737:chemistry / Q000166:cytology; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D016253:Microscopy, Immunoelectron; D009412:Nerve Fibers / Q000737:chemistry / Q000648:ultrastructure; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000276:immunology*; D051596:Neurocalcin; D009638:Norepinephrine / Q000032:analysis; D011108:Polymers; D017729:Presynaptic Terminals / Q000737:chemistry* / Q000648:ultrastructure; D044169:Receptors, Calcium-Sensing
D002135:Calcium-Binding Proteins; D005404:Fixatives; D009419:Nerve Tissue Proteins; D051596:Neurocalcin; D011108:Polymers; D044169:Receptors, Calcium-Sensing; D005557:Formaldehyde; D009638:Norepinephrine; C003043:paraform