Enhancement of inhibitory avoidance and conditioned taste aversion memory with insular cortex infusions of 8-Br-cAMP: involvement of the basolateral amygdala.
There is considerable evidence that in rats, the insular cortex (IC) and amygdala are involved in the learning and memory of aversively motivated tasks. The present experiments examined the effects of 8-Br-cAMP, an analog of cAMP, and oxotremorine, a muscarinic agonist, infused into the IC after inhibitory avoidance (IA) training and during the acquisition/consolidation of conditioned taste aversion (CTA). Posttraining infusion into the IC of 0.3 microg oxotremorine and 1.25 microg 8-Br-cAMP enhanced IA retention. Infusions of 8-Br-cAMP, but not oxotremorine, into the IC enhanced taste aversion. The experiments also examined whether noradrenergic activity in the basolateral amygdala (BLA) is critical in enabling the enhancement of CTA and IA memory induced by drug infusions administered into the IC. For both CTA and IA, ipsilateral infusions of beta-adrenergic antagonist propranolol administered into the BLA blocked the retention-enhancing effect of 8-Br-cAMP or oxotremorine infused into the IC. These results indicate that the IC is involved in the consolidation of memory for both IA and CTA, and this effect requires intact noradrenergic activity into the BLA. These findings provide additional evidence that the BLA interacts with other brain regions, including sensory cortex, in modulating memory consolidation.
Miranda
María I
MI
Center for the Neurobiology of Learning and Memory, Department of Neurobiology and Behavior, University of California, Irvine, California 92697-3800, USA. mmiranda@ifc.uman.mx
McGaugh
James L
JL
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000679:Amygdala / Q000187:drug effects / Q000201:enzymology*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000201:enzymology*; D003214:Conditioning, Classical / Q000187:drug effects / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004789:Enzyme Activation; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D018721:Muscarinic Agonists / Q000494:pharmacology; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology; D009434:Neural Pathways / Q000378:metabolism; D010095:Oxotremorine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013649:Taste / Q000187:drug effects / Q000502:physiology
D000319:Adrenergic beta-Antagonists; D018721:Muscarinic Agonists; D015124:8-Bromo Cyclic Adenosine Monophosphate; D010095:Oxotremorine; D011433:Propranolol; D017868:Cyclic AMP-Dependent Protein Kinases