[Neurosteroids: behavioral aspects and physiological implications].

Area of Science:

• Neuroscience
• Endocrinology
• Behavioral Pharmacology

Context:

• Neurosteroids are synthesized within the nervous system, independent of peripheral glands.
• Key neurosteroids include pregnenolone (PREG), dehydroepiandrosterone (DHEA), and allopregnanolone.
• These molecules modulate neurotransmitter receptors, affecting neuronal excitability and behavior.

Purpose:

• To review the pharmacological actions and physiological correlates of neurosteroids in behavior.
• To highlight the roles of specific neurosteroids (PREG-S, DHEA, allopregnanolone) in various behavioral paradigms.
• To underscore the potential of neurosteroids in addressing age-related cognitive decline.

Summary:

• Pregnenolone sulfate (PREG-S) reduces barbiturate-induced sleeping time via GABAA receptor antagonism.
• Allopregnanolone exhibits anxiolytic effects, involving specific GABAA receptor sites and the amygdala.
• Dehydroepiandrosterone (DHEA) demonstrates anti-aggressive effects, potentially mediated by changes in PREG-S and GABAergic tone.
• Cognitive deficits in aged rats correlate with low hippocampal PREG-S levels, which can be transiently improved by PREG-S administration.

Impact:

• Provides evidence for neurosteroids' direct involvement in regulating fundamental behaviors like sleep, anxiety, and aggression.
• Suggests neurosteroids, particularly PREG-S, may serve as therapeutic agents for age-related memory impairment.
• Identifies neurosteroids as crucial endogenous modulators of neural function with significant behavioral implications.