Transient expression of beta-NADPH diaphorase in developing rat dorsal root ganglia neurons.

We report here that during early fetal rat development, most, if not all, dorsal root ganglion (DRG) cells were stained by the beta-NADPH diaphorase histochemical reaction, indicating that they expressed nitric oxide synthase. During late fetal development, most DRG cells lost their diaphorase activity, but a small subset (located in all DRGs, but primarily in mid-thoracic DRGs) remained diaphorase-positive in adult animals. The transient expression of this enzyme suggests that nitric oxide may play a role during development that differs from its function in mature cells.