Postnatal development of NK1, NK2, and NK3 neurokinin receptors expression in the rat retina

Hiroko Oyamada, Koichi Takatsuji, Emiko Senba, Patrick W. Mantyh, Masaya Tohyama

Research output: Contribution to journalArticlepeer-review

25 Scopus citations


The biological effects of tachykinins are mediated by three distinct receptors, the neurokinin 1 receptor (NK1-R), NK2-R, and NK3-R. There is no information available concerning the development of these receptors in the retina. In the present study, we investigated the localization of tachykinin receptors, using antisera directed against NK1-R, NK2-R, and NK3-R in the adult and developing rat retinas. Numerous NK1-R immunoreactive (NK1-R IR) cells were already observed in the proximal part of the neuroblastic layer in the retina at postnatal day 5 (P5). The distribution and intensity of NK1-R IR cells and processes in the inner nuclear layer (INL) and inner plexiform layer (IPL) at P10 were similar to those of adult retina. Most NK1-R IR cells located in the proximal part of INL, which were morphologically amacrine cells. In the contrast to the early expression of NK1-R IR cells, no NK3-R IR structures existed in the neuronal elements of the retina until P10. NK3-R IR processes were first detected in the outer plexiform layer (OPL) at P10. At P15, NK3-R IR somata were slightly stained in the distal and middle parts of the INL, and NK3-R IR processes were present in the OPL and the upper part of the IPL. During P15-P30, the number of NK3-R IR somata located in the INL remarkably increased. These NK3-R IR cells were morphologically bipolar and amacrine cells. This study provides differential cellular distribution of NK1-R IR cells and NK3-R IR cells in the INL of the rat retina. Our findings suggest that NK1-R and NK3-R are involved in different visual circuits and retinal maturation, and NK3-R may play previously unknown important roles in the visual processes of the rat. Copyright (C) 1999 Elsevier Science B.V.

Original languageEnglish (US)
Pages (from-to)59-70
Number of pages12
JournalDevelopmental Brain Research
Issue number1
StatePublished - Oct 20 1999


  • Amacrine cell
  • Bipolar cell
  • Development
  • Immunocytochemistry
  • Rat
  • Retina
  • Substance P
  • Tachykinin receptor

ASJC Scopus subject areas

  • Developmental Neuroscience
  • Developmental Biology


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