Ontogenic development of prolactin immunoreactive neurons in the rat lateral hypothalamus.
The present study investigated the ontogenic expression of a prolactin-like substance (oPRL-ir) in rat hypothalamus from embryonic day (E) 17 to postnatal day (P) 29. By immunocytochemistry, the oPRL-ir peptide was only detected from P3. As in adults, labeled neurons were found exclusively in the lateral hypothalamic area. By in situ hybridization, with a cocktail of oligonucleotides complementary to the PRL mRNA, no labeling was observed in the hypothalamus, although dense labeling was obtained over the pituitary. With reverse-transcriptase polymerase chain reaction, a 408 bp band, presumably corresponding to an oPRL mRNA, was detected from PO in the LHA, but also in other brain regions. These results suggest that the oPRL-ir neurons do not contain oPRL. The nature of the oPRL-ir peptide is still unknown, but its late onset of expression may be related to its putative involvement in feeding behavior.
Grillon
S
S
CNRS UPRESA 6025 and FR 51, Laboratoire d'Histologie-Embryologie-Cytogénétique, Institut d'Etudes et de Transfert de Gènes, Faculté de Médecine, Besançon, France.
Colard
C
C
Risold
P Y
PY
Fellmann
D
D
Griffond
B
B
D000818:Animals; D005260:Female; D007031:Hypothalamus / Q000737:chemistry / Q000196:embryology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D011247:Pregnancy; D011388:Prolactin / Q000032:analysis* / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
D012333:RNA, Messenger; D011388:Prolactin