Hypothalamic galanin‐immunoreactive neurons projecting to the posterior lobe of the rat pituitary: A combined retrograde tracing and immunohistochemical study
J. Comp. Neurol.. 1990-09-22; 299(4): 405-420
DOI: 10.1002/cne.902990403
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1. J Comp Neurol. 1990 Sep 22;299(4):405-20.
Hypothalamic galanin-immunoreactive neurons projecting to the posterior lobe of
the rat pituitary: a combined retrograde tracing and immunohistochemical study.
Arai R(1), Onteniente B, Trembleau A, Landry M, Calas A.
Author information:
(1)Département de Cytologie, CNRS UA 1199, Université Pierre et Marie Curie,
Paris, France.
To identify the galanin-immunoreactive neurons projecting to the posterior lobe
of the pituitary in the rat hypothalamus, a retrograde tracer (complex of wheat
germ agglutinin-enzymatically inactive horseradish peroxidase-colloidal gold) was
injected into the posterior lobe of the pituitary. Sections of the hypothalamus
were treated with a combination of silver enhancement of retrogradely transported
tracer and immunohistochemistry of galanin. Of the total number of hypothalamic
cells doubly labeled with retrograde tracing and galanin-immunostaining, 56-60%
were found in the supraoptic nucleus, 18-23% in the retrochiasmatic nucleus,
8-10% in the lateral magnocellular portion of the paraventricular nucleus. The
ratio of (number of doubly labeled cells/number of galanin-immunoreactive cells)
in each of the above regions was similar to the ratio of (number of retrogradely
labeled cells/number of Nissl-stained cells) in the supraoptic nucleus. Of all
retrogradely labeled cells in the hypothalamus, 51-56% also contained galaninlike
immunoreactivity.IN CONCLUSION: (1) galanin-immunoreactive fibers in the
posterior lobe of the pituitary originate mainly in the supraoptic nucleus,
retrochiasmatic nucleus, and lateral magnocellular portion of the paraventricular
nucleus, (2) most of galanin-immunoreactive cells in these regions project to the
posterior lobe of the pituitary, and (3) about half the neurons constituting the
hypothalamo-neurohypophyseal system contain galaninlike immunoreactivity.
DOI: 10.1002/cne.902990403
PMID: 1700801 [Indexed for MEDLINE]