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The development of spontaneous electrical activity in spinal cord cultures
Author(s) -
Westbrook G.L.,
Brenneman D.E.
Publication year - 1985
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/0736-5748(85)90082-6
Subject(s) - citation , associate editor , library science , medicine , psychology , computer science
Opiates produce stereospecific depressant effects on sensory-evoked dorsal-horn synaptic network responses in mouse cord-DRG explants (Crain et al, '77,'78). Binding assays show that high levels of opiate receptors develop in these cultures, espec@lly in the DRG neurites (Hiller et al. '78). Opioids also selectively decrease the Ca component of the action potential (AP) of dissociated chick and mouse embryo DRG somas in culture (Mudge et al, '79; Werz and Macdonald, 'BZ), but not of adult mouse DRG neurons in situ (Williams and Zieglgansberger '81). To clarify this difference we compared the distribution of opioid-sensitive neurons in fetal mouse DRG explants cultured alone or attached to spinal cord, for 3-5 wks in vitro. Intracellular recgdings demonstrated that the fraction of DRG somas which showed shortening of the Ca component of the AP during application of opioid peptides was significantly smaller in DRGs attached to cord vs. isolated DRG explants: 50 vs. BO%(Chalazonitis and Crain, '83). Furthermore, wit=n 1-2 wks after trnsecting ce dorsal roots in cord-DRG explants (after 2-3 wks in vitro), the fraction of opioid-sensitive somas in these decentralized DRGs increased again to >80%. These analyses suggest that DRGspinal cord interactions may regulate the level oE functional opiate receptors on the somas of DRG neurons. (Supported by research grant DA-02031 from NIDA)