Ontogeny of tyrosine hydroxylase-positive but dopamine beta-hydroxylase-negative neuron-like cells in the pineal gland of golden hamsters.

The ontogeny of tyrosine hydroxylase (TH)-positive but dopamine beta-hydroxylase (DBH)-negative neuron-like cells in the pineal gland of golden hamsters was investigated by double immunostaining. These cells first appeared on the 6th postnatal day and thereafter increased in number. On the other hand, TH- and DBH-positive nerve fibers, probably originating from the superior cervical ganglion, were already present in the pineal gland at birth.