Androgens in Health and Disease.pdf - E Library

Chapter 15/Androgens and Cognition 291
15
Androgens and Cognition
Monique M. Cherrier, PhD
and Suzanne Craft, PhD
CONTENTS
INTRODUCTION
EVIDENCE FROM ANIMAL STUDIES
EVIDENCE FROM HUMAN STUDIES
ENDOCRINE DISORDERS
SUMMARY
REFERENCES
INTRODUCTION
Androgens and their effects on behavior have been an area of study for over a century.
In 1889, Brown-Sequard, using himself as case study, injected an extract from crushed
animal testicles. He reported that this treatment gave him increased energy, muscular
strength, stamina and mental agility (1). Although crude, this approach led the way to the
discovery of androgens. Since then, the focus of most androgen research has been in the
area of reproductive function. More recently, the focus of attention has turned to hormone
effects on the central nervous system (CNS) and aging, with particular emphasis
on potential antiaging effects of hormone replacement therapy. This chapter will explore
the complex relationship between androgens and cognition. We will first describe mechanisms
by which hormones exert their effects in the CNS, including organizational and
activational effects. Next, we will examine the relationship of androgens and cognition
in humans, including endogenous levels and studies examining hormone manipulation
in healthy young and older populations. Finally, we will examine the relationship between
androgens and cognition as expressed through endocrine disorders that result in excessive
or insufficient hormone levels. This chapter will feature cognition rather than mood,
emotion, or other aspects of human behavior. Readers may refer to other chapters in this
volume or Rubinow and Schmidt (1996) for a review of the relationship between androgens
and mood or behavior (2).
EVIDENCE FROM ANIMAL STUDIES
Hormonal Mechanisms of Action
Several CNS functions are regulated by gonadal steroids and, in particular, testosterone
(T). Examples include prenatal sexual differentiation of the brain, adult sexual
From: Contemporary Endocrinology: Androgens in Health and Disease
Edited by: C. Bagatell and W. J. Bremner © Humana Press Inc., Totowa, NJ
291