Fig. 4.
Oxytocin hnRNA expression in the supraoptic nucleus of morphine-dependent and morphine-withdrawn rats. Hypothalamic sections containing the SON were pretreated and hybridized for oxytocin hnRNA (with a 3H-labeled cDNA probe complementary to 210 bases of intron 1). The sections were exposed to gel emulsion for 50 d. Autoradiographs are of oxytocin hnRNA labeling in supraoptic nucleus neurons in morphine-dependent (A) and morphine-withdrawn (B) rats. Note foci of labeling over the neuronal nuclei (arrows). Scale bars, 20 μm.