[Modification of the deep pineal after ablation of the superficial epiphysis in the golden hamster]

Abstract

In various species (among Rodents: Mesocricetus auratus, Cricetus cricetus, Mus musculus, Meriones libycus, M. shawi et M. crassus; among Cheiroptera: Artibeus jamaicensis etc), the pineal complex is formed by two different portions one superficial situated under the cerebral dura and one deep portion situated between the habenular and posterior commissures. Superficial and deep portions are separated by a tractus of fibers and some pineal cells. Superficial epiphysectomy in the Mesocricetus auratus determines an increase in volume of the deep pineal. The nuclear diameter is also enlarged in this case. The functions of both superficial and deep pineal seem to be closely related. Superficial epiphysectomy is not followed by involution or hypoactivity of the deep pineal. Superficial epiphysectomy also determines changes in the subcommissural and subfornical organs.