Transient prenatal expression of NPY‐Y1 receptor in trigeminal axons innervating the mystacial vibrissae

Abstract

Using immunohistochemistry in combination with confocal laser scanning microscopy, we studied the ontogeny of neuropeptide Y-Y1 receptor (Y1-R) expression in the trigeminal system of the rat. The study was limited to the nerve fibers innervating the mystacial pad and the trigeminal ganglia. In the trigeminal ganglia, Y1-R-immunoreactive (IR) neurons were first observed at E16.5. At this same stage some nerve fibers in the trigeminal ganglia also exhibited Y1-R-like immunoreactivity (LI). Strongly Y1-R-IR nerve fibers innervating the follicles of the mystacial vibrissae were first observed at E18. After double labeling, the Y1-R-LI was found to be colocalized with the neuronal marker protein gene product 9.5. At P1 only weak labeling for the Y1-R was found around the vibrissae follicles, whereas the neurons in the trigeminal ganglia were intensely labeled. The same was true for the adult rat, but at this stage no Y1-R labeling at all was observed in nerve fibers around the vibrissal follicles. These results strongly support an axonal localization of the Y1-R at this developmental stage. The transient expression of the Y1-R during prenatal mystacial pad development suggests a role for the Y1-R in the functional development of the vibrissae.

Distribution of neuropeptide Y Y1 receptors in rodent peripheral tissues

“…Interestingly, in all three studies Y1R‐LI was observed in fibers, suggesting a presynaptic localization. Although Y1Rs have been considered to be primarily postsynaptic, as originally proposed by Wahlestedt and his colleagues (1986), there is now evidence for a presynaptic localization (Peaire et al, 1997; Pickel et al, 1998; St‐Pierre et al, 2000; Kopp et al, 2002; Ubink et al, 2001; Brumovsky et al, 2002). The fact that a few enteroendocrine cells were positive for the Y1R suggests that secretion of a peptide hormone and/or biogenic amine (Polak and Bloom, 1988; Sundler and Hâkanson, 1988) in single instances may be regulated by NPY.…”

“…Localization of Y1R and Y2R was studied at the histochemical level with ligand binding techniques and autoradiography, in addition to the functional/pharmacologic analysis (Pheng and Regoli, 2000; see references above). More recently, immunohistochemical studies with Y1R antibodies have so far described the distribution of the Y1R in sensory neurons (Zhang et al, 1994b, 1999; Ubink et al, 2001; Brumovsky et al, 2002), in cerebral blood vessels (Bao et al, 1997), in small arteries and arterioles in the genital tract (Kopp et al, 1997), and in blood vessels and a few enteroendocrine cells and neurons and axons in the intestine (Jackerott and Larsson, 1997; Peaire et al, 1997). In the present study, Y1R‐LI was found not only in smooth muscle cells of blood vessels but also in capillary walls, in a reticulum in the mouse spleen, and in some epithelial and endocrine cells, as will be discussed below.…”

Expression of UDP‐N‐acetyl‐α‐D‐galactosamine–polypeptide galNAc N‐acetylgalactosaminyl transferase‐3 in relation to differentiation and prognosis in patients with colorectal carcinoma

“…An affinity‐purified rabbit polyclonal antibody directed against a C‐terminus fragment (amino acids 370‐382) of the rat Y1 receptor (Ab 96106) was produced by the Antibody/RIA Core of the CURE/Digestive Diseases Research Center and generously provided by H. Wong and J.H. Walsh of the University of California, Los Angeles (Zhang et al, 1994; Bao et al, 1997; Ubink et al, 2001). Specificity of immunostaining was evaluated by preadsorbing the antibody with 10 −6 M synthetic Y1 370‐382 .…”

Localization of neuropeptide Y1 receptor immunoreactivity in the rat retina and the synaptic connectivity of Y1 immunoreactive cells

“…Walsh of the University of California, Los Angeles (Zhang et al, 1994;Bao et al, 1997;Ubink et al, 2001). Specificity of immunostaining was evaluated by preadsorbing the antibody with 10 -6 M synthetic Y1 [370][371][372][373][374][375][376][377][378][379][380][381][382] .…”

“…Specificity of immunostaining was evaluated by preadsorbing the antibody with 10 -6 M synthetic Y1 [370][371][372][373][374][375][376][377][378][379][380][381][382] . Specificity of immunostaining of this Y1 antibody was also evaluated by using Y1 receptor-deficient mice (Ubink et al, 2001). Sections from Y1-deficient mice did not show any specific Y1 immunoreactivity.…”