The transition from memory retrieval to extinction
Memory is measured by measuring retrieval. Retrieval is often triggered by the conditioned stimulus (CS); however, as known since Pavlov, presentation of the CS alone generates extinction. One-trial avoidance (IA) is a much used conditioned fear paradigm in which the CS is the safe part of a training apparatus, the unconditioned stimulus (US) is a footshock and the conditioned response is to stay in the safe area. In IA, retrieval is measured without the US, as latency to step-down from the safe area (i.e., a platform). Extinction is installed at the moment of the first unreinforced test session, as clearly shown by the fact that many drugs, including PKA, ERK and protein synthesis inhibitors as well as NMDA receptor antagonists, hinder extinction when infused into the hippocampus or the basolateral amygdala at the moment of the first test session but not later. Some, but not all the molecular systems required for extinction are also activated by retrieval, further endorsing the hypothesis that although retrieval is behaviorally and biochemically necessary for the generation of extinction, this last process constitutes a new learning secondary to the unreinforced expression of the original trace.
Main Authors: | Cammarota,Martín, Barros,Daniela M., Vianna,Mónica R.M., Bevilaqua,Lia R.M., Coitinho,Adriana, Szapiro,Germán, Izquierdo,Luciana A., Medina,Jorge H., Izquierdo,Iván |
---|---|
Format: | Digital revista |
Language: | English |
Published: |
Academia Brasileira de Ciências
2004
|
Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652004000300011 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Similar Items
-
Effects of intrahippocampal administration of the phosphatase inhibitor okadaic acid: Dual effects on memory formation
by: Vianna,Monica R.M., et al.
Published: (2010) -
The extinction of conditioned fear: structural and molecular basis and therapeutic use
by: Cammarota,Martín, et al.
Published: (2007) -
Short- and long-term memory: differential involvement of neurotransmitter systems and signal transduction cascades
by: VIANNA,MÔNICA R.M., et al.
Published: (2000) -
A link between the hippocampal and the striatal memory systems of the brain
by: Rossato,Janine I., et al.
Published: (2006) -
Treatment of fear memories: interactions between extinction and reconsolidation
by: Fiorenza,Natália G., et al.
Published: (2011)