Pineal Complex of Rats: Effects of Superficial Pinealectomy on the Deep Pineal

Abstract

Previous studies have shown that in rodents the pineal complex may consist of two parts, i.e. the small deep pineal and the large superficial pineal. As commonly used techniques of pinealectomy remove the superficial pineal only, it was decided to examine what effect this operation has on the deep pineal in male Sprague-Dawley rats. 3 and 6 weeks after superficial pinealectomy, the deep pineal exhibited a clear decrease in volume, due to an atrophy of the intrinsic pinealocytes. An atrophy was still noticeable after 6 or 12 months. It is concluded that after superficial pinealectomy the deep pineal is not an important factor with respect to melatonin formation, in particular, as there are extrapineal sites of melatonin formation.

Neuromodulation of the Pineal Gland via Electrical Stimulation of Its Sympathetic Innervation Pathway

“…However, since usual pinealectomy removes only the superficial portion of the gland, leaving the deep pineal intact, one cannot discount the possibility that circulating melatonin levels may be due to contribution from the deep portion of the gland. Yet, atrophy of the deep pineal is apparent following superficial pinealectomy in rats (Heidbuchel and Vollrath, 1983), which most likely results in impaired function, although this has not been confirmed. This is not surprising since the sympathetic fibres that innervate the gland first supply the superficial pineal before coursing down the stalk and supplying innervation to the deep pineal.…”

Caracterização do eixo imune-pineal: mecanismo de ação do controle da função pineal pela citocina pró-inflamatória TNF

“…Em humanos, a pineal desenvolve-se a partir de uma evaginação do teto do terceiro ventrículo (Oksche, 1965) que inicia-se no segundo mês de gestação e sua localização é mantida na vida adulta. Em roedores, a pineal migra dorso-caudalmente durante a ontogênese e se localiza centralmente no topo do cérebro entre os hemisférios cerebrais e o cerebelo (Vollrath, 1981;Heidbüchel & Vollrath, 1983;Møller & Baeres, 2002).…”