Estrogen synthesis in the central nucleus of the amygdala following middle cerebral artery occlusion: Role in modulating neurotransmission

• Published in: Neuroscience 2005, Vol.135 (4), p.1141-1153
• Main Authors: Saleh, T.M., Connell, B.J., Legge, C., Cribb, A.E.
• Format: Article
• Language: English
• Subjects: Amygdala - drug effects; Amygdala - metabolism; Animals; Aromatase Inhibitors - administration & dosage; Autonomic Nervous System - drug effects; Autonomic Nervous System - physiology; autonomic tone; Biological and medical sciences; Blood Pressure - drug effects; Brain Chemistry - drug effects; Brain Chemistry - physiology; Estradiol - administration & dosage; Estradiol - analogs & derivatives; Estrogen Antagonists - administration & dosage; estrogen synthesis; Estrogens - biosynthesis; Estrogens - blood; Excitatory Amino Acid Antagonists - administration & dosage; Fundamental and applied biological sciences. Psychology; Heart Rate - drug effects; Infarction, Middle Cerebral Artery - physiopathology; Injections, Intraventricular; letrozole; Male; Medical sciences; Microdialysis; Neurology; Nitriles - administration & dosage; NMDA and non-NMDA receptors; Piperazines - administration & dosage; Quinoxalines - administration & dosage; Rats; Rats, Sprague-Dawley; stroke; Synaptic Transmission - drug effects; Synaptic Transmission - physiology; Testosterone - blood; Triazoles - administration & dosage; Vascular diseases and vascular malformations of the nervous system; Vertebrates: nervous system and sense organs
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2005.06.061

Stroke-induced lesions of the insular cortex in the brain have been linked to autonomic dysfunction (sympathoexcitation) leading to arrhythmogenesis and sudden cardiac death. In experimental models, systemic estrogen administration in male rats has been shown to reduce stroke-induced cell death in the insular cortex as well as prevent sympathoexcitation. The central nucleus of the amygdala has been postulated to mediate sympathoexcitatory output from the insular cortex. We therefore set out to determine if endogenous estrogen levels within the central nucleus of the amygdala are altered following stroke and if microinjection of estrogen into the central nucleus of the amygdala modulates autonomic tone. Plasma estrogen concentrations were not altered by middle cerebral artery occlusion (22.86±0.14 pg/ml vs. 21.24±0.33 pg/ml; P>0.05). In contrast, estrogen concentrations in the central nucleus of the amygdala increased significantly following middle cerebral artery occlusion (from 20.83±0.54 pg/ml to 76.67±1.59 pg/ml; P