I have a few questions
In your study you did not mention the time of day that you obtained the pineal glands from the rats and hamsters. Can I presume it was mid dark?
Have you noticed any difference in the amount of labelling in the deep and superficial pineals between day and night?
Why do you think there is a discrepancy between your work and the Mennenga et al observation of melatonin in the nucleus? Why should it ever be in the nucleus of the cell that synthesises it?