Main description:

It is well known that the class of steroid hormones known as estrogens have powerful effects on organs related to reproduction such as the uterus and the breast. What is less well known is that estrogens also profoundly modulate brain function and behavior. Estrogens, such as estradiol, can occur in brain as the result of ovarian secretion of the hormone into the blood that then finds its way to the brain. In male vertebrates, the testes secrete androgens, such as
testosterone, into the blood and this class of steroid hormones can be converted into estrogens in the brain via the action of the enzyme aromatase which is expressed in the male brain in many species. Finally estradiol can be synthesized de novo from cholesterol as it has been shown in a variety of
species that all the enzymes required to synthesize estrogens are expressed in the brain. This book collects chapters by experts in the field that considers, how estradiol is synthesized in the brain and what its effects are on a variety of behaviors. Special attention is paid to the enzyme aromatase that is distributed in discrete regions of the brain and is highly regulated in a sex specific and seasonal specific manner. Recently it has become clear that estrogens can act in the brain at
two very different time scales, one is rather long lasting (days to weeks) and involves the modulation of gene transcription by the hormone-receptor complex. A second mode of action is much quicker and involves the action of estrogens on cell membranes that can result in effects on second messenger
systems and ultimately behavior within minutes. Thus this book highlights novel views of estrogen action that are still under-appreciated namely that estrogens have significant effects on the male brain and that they can act on two very different times scales. This volume will be of interest to both basic researchers and clinicians interested in the action of estrogens.

Contents:

Part I. HISTORICAL ORIGINS AND CONCEPTUAL BASIS OF THE FIELD ; 1. Naftolin F. The aromatization hypothesis and the discovery of estrogen synthesis by brain cells ; AROMATASE, ITS BRAIN DISTRIBUTION AND REGULATION ; 2. Callard GV, Greytak SR, Novillo A, Cotter KA & Meyer R. Brain aromatase in fishes: Historical perspective and comparative approaches ; 3. Roselli CE : The Distribution and regulation of aromatase in the mammalian brain: from mice to monkeys ; 4. Conley A, Orr VN, Trainor BC, Berger T & Hughes A. Multiple forms of aromatase in suiforms: tissue distribution, regulation and functional significance ; 5. Biegon A. Fowler J, Kim S, Logan J, Pareto D & Wang G-J. Regional distribution of aromatase in the human brain ; 6. Saldanha CJ, Remage-Healey L & Schlinger BA. Neuroanatomical distribution of aromatase in birds: cellular and subcellular analyses ; 7. Pellegrini E, Vaillant C, Diotel N, Benquet P, Brion F & Kah O. Expression, regulation and potential functions of aromatase in radial glial cells of the fish brain ; 8. Harada N. Molecular mechanisms controlling brain aromatase expression ; BEHAVIORAL (GENOMIC) EFFECTS OF LOCALLY PRODUCED ESTROGEN IN THE BRAIN ; 9. Clemens LG. The origin of the aromatization hypothesis 1970-1990 ; 10. Schlinger BA & Balthazart J. Aromatase and behavior: concepts gained from studies of aromatase in the avian brain ; 11. Heimovics SA, Fokidis HB & Soma KK. Brain Aromatase and Territorial Aggression Across the Seasons in Male Song Sparrows ; 12. Cohen RE & Wade J. Testosterone metabolism in reptiles ; 13. Krohmer RW. Aromatase, low temperature dormancy and reproduction in the red-sided garter snake ; 14. Gillies GE. Differential actions of estrogens in the male and female brain: a case for sex-specific medicines ; AROMATASE AND SEXUAL DIFFERENTIATION ; 15. Sodersten P. A historical and personal perspective on the aromatization revolution: Steinach confirmed ; 16. McCarthy MM, Wright CL & Konkle ATM. Aromatase and sexual differentiation of the rodent brain: The old, the new and the unexpected ; 17. Bakker J. Aromatase and sexual differentiation: lessons from the aromatase and alpha-fetoprotein knockout mice ; 18. Adkins-Regan E. Aromatase, estrogens and differentiation of sexual behavior and partner preference in birds ; AROMATASE AND BRAIN PROTECTION OR REPAIR ; 19. Azcoitia I, Arevalo MA & Garcia-Segura LM. Brain aromatase and neuroprotection in mammals ; Duncan KA & Saldanha CS. Inducible aromatase in astroglia: protection and recovery from neural perturbation in birds ; RAPID CHANGES IN AROMATASE ACTIVITY & RAPID EFFECTS OF ESTROGENS ; 20. Laredo SA & Trainor BC. Photoperiodic regulation of estrogen-dependent aggression ; 21. Charlier TD, Cornil CA, Ball GF & Balthazart J. Cellular mechanisms controlling rapid changes in brain aromatase activity ; 22. Cornil CA, Dickens MJ, Ball GF & Balthazart J. Rapid modulation of aromatase activity by social and environmental stimuli in quail ; 23. Tremere LA & Pinaud R. Modulation of Central Auditory Processing by a Brain-Generated Estrogen: Rapid Effects on Neural Coding, Discrimination and Behavior ; 24. Remage-Healey L. Acute synthesis and action of estrogens in communication circuits ; 25. Thompson RR & Mangiamele LA. Rapid Effects of Estradiol on Behavioral and Physiological Responses Related to Reproduction in Male Goldfish ; 26. Balthazart J & Ball G.F. Concluding statements and current challenges ; Index