Rat pinealectomy: a modified direct visual approach

Abstract

Purpose: To report a new, direct visual approach for rat pinealectomy. Methods: Eighty adult female rats (Rattus norvegicus albinus EPM-1 strain) were weighted and anesthetized intraperitoneally with 15 mg/kg xylazine and 30 mg/kg ketamine. The animal was fastened to a dissection table, an incision was made in the skin and the subcutaneous tissue, bringing the lambda into view. The skullcap was opened with a dental drill, bringing the cerebral hemispheres and the superior sagittal sinus into view. The pineal gland, located under the venous sinus, was removed in a single piece using tweezers. Next, the bone fragment was returned to its place and the surgical layers were sutured. Results: This new technique is easy to be done, avoids bleedings and removes only the pineal gland without damage to the remaining encephalon. In addition it makes possible the achievement of a sham surgery, allowing the pineal gland to remain intact. Conclusion: The proposed technique intends to facilitate studies aiming to better understanding the complexity and importance of the pineal gland on reproductive and other body systems. Key words: Pineal Gland. Melatonin. Genitalia, Female. Surgery. Rats. RESUMOObjetivo: Apresentar nova técnica para pinealectomia em ratos. Métodos: 80 ratos adultos fêmeas (Rattus norvegicus albinus) foram pesados e em seguida anestesiados por via intraperitoneal com xilazina e cetamina. Em seguida os animais foram fixados em uma prancha de cortiça e feita uma incisão na pele e no tecido subcutâneo, na região superior da cabeça, evidenciando a junção dos ossos parietais e occipital. Na região do lambda, realizou-se uma perfuração circular, na calota craniana, com o auxilio de uma broca (4 mm) acoplada a um micromotor. Nesse orifício, após a dissecação da dura-mater visibiliza-se a confluência dos seios venosos longitudinal e transverso. Com o auxilio de uma pinça curva esses seios são deslocados, ligados e identificada a glândula pineal, que pode ser removida em peça única. Em seguida, o fragmento ósseo é devolvido ao seu lugar e as camadas cirúrgicas suturadas. Resultados: Esta nova técnica é fácil de ser feita, evita hemorragias e só remove a glândula pineal, sem prejuízos para o restante do encéfalo. Além disso, possibilita a realização de uma cirurgia sham, visto que a glândula pineal permanece sem alterações. Conclusão: Espera-se que a técnica proposta facilite estudos visando a uma melhor compreensão da complexidade e importância da glândula pineal sobre a reprodução e outros sistemas do organismo.

Transcutaneous Auricular Vagus Nerve Stimulation Triggers Melatonin Secretion and Is Antidepressive in Zucker Diabetic Fatty Rats

“…To find out the role of pineal gland in depressive behavior and to explore whether there is another melatonin source, the effect of taVNS were also examined in pinealectomized (Px) rats. Pineal gland was removed from rats by referring to a reported method [17] . Briefly, 10 male ZDF rats were weighted and anesthetized intraperitoneally with 50 mg/kg sodium pentobarbital.…”

Effects of melatonin on histomorphology and on the expression of steroid receptors, VEGF, and PCNA in ovaries of pinealectomized female rats

“…All animals were anesthetized with 15 mg/kg of xylazine (Rompun) associated with 30 mg/kg of ketamine (Ketalar) via the intraperitoneal route following the method used previously (11,12,16). The same procedure was adopted for the sham-pinealectomized animals, except for the removal of the pineal gland.…”

Pinealectomy increases thermogenesis and decreases lipogenesis

“…Rats were overnight fasted before surgery. Pnx was performed as described previously [19]. Rats were anesthetized with 5% isoflurane (JW Pharmaceutical Corporation, Seoul, Korea) in 30% oxygen and 70% nitrous oxide.…”