Steroid hormones and brain development: some guidelines for understanding actions of pseudohormones and other toxic agents
Gonadal, adrenal, and thyroid hormones affect the brain directly, and the sensitivity to hormones begins in embryonic life with the appearance of hormone receptor sites in discrete populations of neurons. Because the secretion of hormones is also under control by its neural and pituitary targets, the brain-endocrine axis during development is in a delicately balanced state that can be upset in various ways, and any agent that disrupts normal hormone secretion can upset normal brain development. Moreover, exogenous substances that mimic the actions of natural hormones can also play havoc with CNS development and differentiation. This paper addresses these issues in the following order: First, actions of glucocorticoids on the developing nervous system related to cell division dendritic growth and neurotransmitter phenotype will be presented followed by a discussion of the developmental effects of synthetic steroids. Second, actions of estrogens related to brain sexual differentiation will be described, followed by a discussion of the actions of the nonsteroidal estrogen, diethylstilbestrol, as an example of exogenous estrogenic substances. The most important aspect of the potency of exogenous estrogens appears to be the degree to which they either bypass protective mechanisms or are subject to transformations to more active metabolites. Third, agents that influence hormone levels or otherwise modify the neuroendocrine system, such as nicotine, barbiturates, alcohol, opiates, and tetrahydrocannabinol, will be noted briefly to demonstrate the diversity of toxic agents that can influence neural development and affect personality, cognitive ability, and other aspects of behavior. 53 references.
- Research Organization:
- Rockefeller Univ., New York, NY
- OSTI ID:
- 5589053
- Journal Information:
- Environ. Health Perspect.; (United States), Vol. 74
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALCOHOLS
TOXICITY
BRAIN
CELL DIFFERENTIATION
SENSITIVITY
NICOTINE
STEROIDS
BIOLOGICAL FUNCTIONS
SECRETION
BARBITURATES
OPIUM
RECOMMENDATIONS
ALKALOIDS
AMINES
ANALGESICS
ANESTHETICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZINES
AZOLES
BODY
CENTRAL NERVOUS SYSTEM
CENTRAL NERVOUS SYSTEM DEPRESSANTS
DRUGS
FUNCTIONS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
HYPNOTICS AND SEDATIVES
NARCOTICS
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
PARASYMPATHOLYTICS
PARASYMPATHOMIMETICS
PYRIDINES
PYRIMIDINES
PYRROLES
PYRROLIDINES
560300* - Chemicals Metabolism & Toxicology