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Early locus coeruleus lesions increase the density of β‐adrenergic receptors in the main olfactory bulb of rats
Author(s) -
Woo Cynthia C.,
Wilson Donald A.,
Sullivan Regina M.,
Leon Michael
Publication year - 1996
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/s0736-5748(96)00041-x
Subject(s) - olfactory bulb , locus coeruleus , adrenergic receptor , endocrinology , medicine , norepinephrine , receptor , olfactory system , adrenergic , biology , chemistry , neuroscience , central nervous system , dopamine
Abstract Norepinephrine is supplied to both deep and superficial layers of the olfactory bulb through dense projections from the locus coeruleus. 16 Beta‐adrenergic receptors are located in nearly all bulb laminae, with high‐density foci of β‐1 and β‐2‐adrenoceptors present in the glomerular layer. 29 Early olfactory experiences that increase norepinephrine levels in the bulb also decrease the density of β‐1‐ and β‐2‐adrenoceptors, as well as the number of high‐density glomerular foci of β‐2‐receptors. 30 Changes in bulb norepinephrine levels, therefore, may affect the density of β‐adrenoceptors in the bulb. In the current study, we test this hypothesis by performing unilateral lesions of the locus coeruleus with 6‐hydroxydopamine on postnatal day 4, and examining the density of β‐1‐ and β‐2‐adrenergic receptors in the main olfactory bulb of the rat using 125 I‐labeled iodopindolol receptor autoradiography on postnatal day 19. Locus coeruleus destruction resulted in a statistically significant increase in the density of adrenergic receptors in the ipsilateral bulb compared to the contralateral bulb. Both β‐1‐ and β‐2‐adrenoceptor subtypes increased in density with this manipulation, although the number of glomerular layer high‐density β‐2 foci was not significantly different between the two bulbs. These results are consistent with the hypothesis that changes in olfactory bulb norepinephrine can regulate the density of β‐adrenergic receptors in the bulb.