**12. References**


[5] Koch AM, Zink S, Singer H, Dittrich S. B-type natriuretic peptide levels in patients with functionally univentricular hearts after total cavopulmonary connection. Eur J Heart Fail 2008;10:60–62.

**Chapter 2** 

© 2012 Karakas and Coskun, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

© 2012 Karakas and Coskun, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

**Intraamygdalar Melatonin** 

Additional information is available at the end of the chapter

with increasing body weight (Binkley, 1988).

intracranial pineal organ (Arendt, 1995).

Alper Karakas and Hamit Coskun

http://dx.doi.org/10.5772/48690

**1. Introduction** 

**1.1.The pineal gland** 

**Administration and Pinealectomy Affect** 

**Anxiety Like Behavior and Spatial Memory** 

The pineal gland, which is called as "seat of the rational soul" by Descartes, is a pine shaped, unpaired organ located at the epithalamus of the brain. The invagination of the diencephalon develops the pineal gland and it is connected to the habenular commissure with a stalk. There is a close link between the pineal gland and the third ventricle of the brain and the area of the third ventricle receiving the pineal stalk is known as the pineal recess. The pineal gland has an endogenous, circadian(around 24 hours) rhythmic pattern in its metabolic and/or neural activity. The weight and the volume of the pineal gland show big differences within and between the species depending on the time of year, age and the physiological status of the animal. The volume of the pineal gland tends to increase in line

The mammalian pineal is specialized for only secretion whereas fish and amphibian pineal glands acting as a photoreceptive organ and in reptiles and in birds, pineal gland is both receiving the light and has secretory function. In some birds and lower vertebrates, pineal gland also works as a rhythm generator but in mammals it is working in the coordination of rhythm physiology. In mammals, the rhythm generator is located in the suprachiasmatic nuclei of the hypothalamus (Refinetti et al, 1994). Some fish, amphibians and reptiles have a pineal gland with the two components, namely, the extracranial parietal organ and the

The neuronal innervation of the pineal gland in lower vertebrates and mammals is not alike because of the lost of the efferent innervation during the phylogenesis in lower vertebrates.


Alper Karakas and Hamit Coskun

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/48690
