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Opioid modulation of cell proliferation in the ventricular zone of adult zebra finches (Taenopygia guttata)
Author(s) -
Khurshid Nazia,
Hameed L. Shahul,
Mohanasundaram Sivaraj,
Iyengar Soumya
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.09-146746
Subject(s) - gliogenesis , neurogenesis , endogenous opioid , (+) naloxone , endocrinology , enkephalin , medicine , biology , opioid , in situ hybridization , opioid receptor , neuroscience , receptor , microbiology and biotechnology , neural stem cell , stem cell , gene expression , biochemistry , gene
Besides modulating pain, stress, physiological functions, motivation, and reward, the opioid system has been implicated in developmental and adult mammalian neurogenesis and gliogenesis. In adult male songbirds including zebra finches, neurons generated from the ventricular zone (VZ) of the lateral ventricles are incorporated throughout the telencephalon, including the song control nuclei, HVC, and area X. Although the endogenous opioid met‐enkephalin is present in neurons adjacent to the VZ and is upregulated in song control regions during singing, it is not known whether the opioid system can modulate adult neurogenesis/gliogenesis in zebra finches. We used quantitative RT‐PCR and in situ hybridization to demonstrate that µ‐ and δ‐opioid receptors are expressed by the VZ of adult male zebra finches. Treating cultured VZ cells from male birds with the opioid antagonist naloxone led to an increase in cell proliferation measured by 5‐bromo‐2‐deoxyuridine incorporation, whereas administering met‐enkephalin had the opposite effect, compared with saline‐treated cultures. Systemically administering naloxone (2.5 mg/kg body wt) to adult male zebra finches for 4 d also led to a significant increase in cell proliferation in the ventral VZ of these birds, compared with saline‐treated controls. Our results show that cell proliferation is augmented by naloxone in the VZ adjacent to the anterior commissure, suggesting that the endogenous opioids modulate adult neurogenesis/gliogenesis by inhibiting cell proliferation in songbirds.—Khurshid, N., Hameed, L. S., Mohanasundaram, S., Iyengar, S. Opioid modulation of cell proliferation in the ventricular zone of adult zebra finches ( Taenopygia guttata ). FASEB J. 24, 3681–3695 (2010). www.fasebj.org