Beta1- and beta2-adrenoceptors in basolateral nucleus of amygdala and their roles in consolidation of fear memory in rats.
It is known that beta-adrenoceptor (AR) in the basolateral nucleus of amygdala (BLA) plays an essential role in fear memory formation. However, the cellular and subcellular distributions of beta1- and beta2-ARs in the BLA and their roles in fear memory formation are poorly understood. Here, we report that both beta1- and beta2-ARs are predominantly expressed in BLA neurons but not in astrocytes. beta1-AR is distributed in the cell membrane and cytoplasm of neurons, whereas beta2-AR is localized not only in the cell membrane and cytoplasm but also in the nucleus. Intra-BLA infusion of the beta1-AR antagonist metoprolol and atenolol or the beta2-AR antagonist ICI118551 and butoxamine produces a severe deficit in 24-h auditory fear memory, leaving 1-h memory intact. Western-blot analysis reveals that the protein level of cytoplasmic beta1-AR significantly increases 2- and 4-h postconditioning, whereas that of cytoplasmic or nuclear beta2-AR is unchanged. The present results indicate that beta1- and beta2-ARs in the BLA have differential subcellular localizations and both are required for the consolidation of auditory fear memory.
Qu
Li-Li
LL
Institute of Neurobiology and State Key Laboratory of Medical Neurobiology, Institutes of Brain Science, Fudan University, Shanghai 200032, China.
Guo
Nan-Nan
NN
Li
Bao-Ming
BM
D000161:Acoustic Stimulation; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000679:Amygdala / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D015153:Blotting, Western; D005239:Fear / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D008297:Male; D008568:Memory / Q000502:physiology*; D018613:Microscopy, Confocal; D009474:Neurons / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018342:Receptors, Adrenergic, beta-1 / Q000187:drug effects / Q000378:metabolism*; D018343:Receptors, Adrenergic, beta-2 / Q000187:drug effects / Q000378:metabolism*
D000319:Adrenergic beta-Antagonists; D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2