Effect of Sympathetic ganglionectomy on the Pineal Gland in Rhesus Monkey

The light microscopic structure and the effect of superior cervical ganglionectomy on the pineal gland of Rhesus monkey was studied in 24 animals. The animals were divided into three groups. Group I normal controls, Group II after unilateral and Group III after bilateral ganglionectomy. The animals in group II were sacrificed 15 days and group III were sacrificed 21 days after the operation. Every seventh slide of serial paraffin sections were stained with H&E stain, Red Holzer’s stain for glial fibers, Weigert’s and Van Gieson’s stain, Weil’s stain for myelin sheath, Peter’s protein silver stain for nerve fibers and Glee’s stain for degenerating nerve fibers . A close relationship between the processes of the pinealocytes and interstitial cells and capillaries was suggestive of an exchange of material between the two types of cells and blood vessels. Two types of acervulei in the control group, type I comprising of concentric whorl around a central heterochromatic nucleus and the type II made up of superimposed droplets were noted in the control group. Degenerating nerve fibers, cell free areas and acervulei of superimposed secretions were seen in group II and III suggesting an autonomic nervous control on the secretions of the gland.