Surgical pinealectomy in birds

Research output: Chapter in Book/Report/Conference proceedingChapter (peer-reviewed)

Colleges, School and Institutes

Abstract

ABSTRACT
In contrast to mammals, birds are equipped with a complex and diverse multi-oscillatory circadian pacemaking system. It varies greatly between species and it appears to be flexible within species and even within individuals. The latter is particularly obvious for the melatonin signal which, depending on season or latitude, is either characterized by a high- or a low-amplitude rhythm and is a direct reflection of nightlength. Melatonin, either exclusively released from the pineal gland or from the pineal gland and the retina plays a central role in circadian organisation in birds. Changes of circulating melatonin result in corresponding changes of the amplitude of the pacemaker as a whole and has to be considered in pinealectomy experiments in birds. The components of the circadian pacemaking system in birds, i.e. the pineal gland, the retina, and the hypothalamic oscillators, interact with each other to produce stable organismal circadian rhythmicity in a species-specific way, i.e. the functional role of these oscillators for circadian pacemaking at the organismal level varies strongly between avian species. Generally, birds have well developed pineal glands and only in nocturnal species rudimentary pineal glands can be found. The avian pineal gland (epiphysis cerebri) is located at the dorsal surface of the brain embedded between the triangular space between the cerebral hemispheres and the cerebellum. Pinealectomy, as described in this chapter, is a highly reliable surgical procedure that has been developed and used for many years in avian circadian research at the Max-Planck-Research-Centre for Ornithology by Eberhard Gwinner and co-workers.

Details

Original languageEnglish
Title of host publicationSTEP BY STEP EXPERIMENTAL PINEALECTOMY TECHNIQUES IN ANIMALS FOR RESEARCHERS
Publication statusAccepted/In press - 2013

Keywords

  • melatonin; pineal gland; circadian system; pinealectomy