Immunohistochemical demonstration of tyrosine hydroxylase (TH)-positive but dopamine β-hydroxylase (DBH)-negative neuron-like cells in the pineal gland of golden hamsters

Double immunostaining for tyrosine hydroxylase (TH) and dopamine β-hydroxylase (DBH) in the pineal gland revealed many TH-positive but DBH-negative, neuron-like cells in golden hamsters, but not in rats and gerbils. They were scattered in the meshwork of TH- and DBH-positive nerve fibers throughout the parenchyma. Their cell bodies were oval or spindle-shaped (maximum diameter: 15–20 μm). They had sometimes one or two short cell processes. Bilateral superior cervical ganglionectomy diminished strikingly the number of TH- and DBH-positive nerve fibers, but did not affect the number of TH-positive cells.