Transient prenatal expression of NPY-Y1 receptor in trigeminal axons innervating the mystacial vibrissae.
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.
Ubink
R
R
Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden. Ruud.Ubink@neuro.ki.se
Kopp
J
J
Wong
H
H
Walsh
J H
JH
Pedrazzini
T
T
Hökfelt
T
T
D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000378:metabolism*; D018859:Hair Follicle / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D051381:Rats; D017207:Rats, Sprague-Dawley; D017476:Receptors, Neuropeptide Y / Q000378:metabolism*; D013869:Thiolester Hydrolases / Q000378:metabolism; D014276:Trigeminal Nerve / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism* / Q000648:ultrastructure; D043222:Ubiquitin Thiolesterase; D014738:Vibrissae / Q000196:embryology / Q000254:growth & development* / Q000294:innervation*
D017476:Receptors, Neuropeptide Y; C097212:neuropeptide Y-Y1 receptor; D013869:Thiolester Hydrolases; D043222:Ubiquitin Thiolesterase