Post-retrieval disruption of a cocaine conditioned place preference by systemic and intrabasolateral amygdala beta2- and alpha1-adrenergic antagonists.
Previous work has demonstrated post-retrieval impairment in associative learning paradigms, including those mediated by drugs of abuse, using nonspecific beta-adrenergic receptor (beta-AR) antagonists. Remarkably little is known about the role of the specific beta-AR subtypes, or other adrenergic receptors, in these effects. The current study examined the effects of beta(1) and beta(2), as well as alpha(1)-adrenergic receptor antagonism following retrieval of a cocaine conditioned place preference (CPP). We found that rats administered the beta(2) antagonist ICI 118,551 (8 mg/kg intraperitoneal [IP]) or the alpha(1) antagonist prazosin (1 mg/kg IP) following a drug-free test for CPP showed attenuated preference during a subsequent test, while the beta(1) antagonist betaxolol (5 or 10 mg/kg IP) and a lower dose of prazosin (0.3 mg/kg IP) had no effect. Furthermore, post-test microinfusion of ICI 118,551 (6 nmol/side) or prazosin (0.5 nmol/side) into the basolateral amygdala (BLA) also impaired a subsequent preference. Systemic or intra-BLA ICI 118,551 or prazosin administered to rats in their home cages, in the absence of a preference test, had no effect on CPP 24 h later. ICI 118,551 also attenuated the FOS response in the BLA induced by the CPP test. These results are the first to demonstrate a role for alpha(1)- and beta(2)-specific adrenergic mechanisms in post-retrieval memory processes. These systemic and site-specific injections, as well as the FOS immunohistochemical analyses, implicate the importance of specific noradrenergic signaling mechanisms within the BLA in post-retrieval plasticity.
Bernardi
Rick E
RE
Department of Behavioral Neuroscience, Oregon Health and Science University, Portland, Oregon 97239, USA. rick.bernardi@zi-mannheim.de
Ryabinin
Andrey E
AE
Berger
S Paul
SP
Lattal
K Matthew
KM
D018674:Adrenergic Antagonists / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000679:Amygdala / Q000187:drug effects* / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D003042:Cocaine / Q000009:adverse effects*; D003216:Conditioning, Operant / Q000187:drug effects*; D018765:Dopamine Uptake Inhibitors / Q000009:adverse effects*; D004333:Drug Administration Routes; D011939:Mental Recall / Q000187:drug effects*; D008845:Microinjections / Q000379:methods; D016761:Oncogene Proteins v-fos / Q000378:metabolism; D011224:Prazosin / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D018674:Adrenergic Antagonists; D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D018765:Dopamine Uptake Inhibitors; D016761:Oncogene Proteins v-fos; D011412:Propanolamines; C026777:ICI 118551; D003042:Cocaine; D011224:Prazosin