The involvement of the GABA ergic system in the formation and expression of the extinction memory in the crab N eohelice granulata

• Published in: The European journal of neuroscience 2013-11, Vol.38 (9), p.3302-3313
• Main Authors: Tano, Martin Carbó, Molina, Victor A., Pedreira, Maria Eugenia
• Format: Article
• Language: English
• ISSN: 0953-816X; 1460-9568
• DOI: 10.1111/ejn.12328

There is growing interest in the neurobiological mechanisms involved in the extinction of aversive memory. This cognitive process usually occurs after repeated or prolonged presentation of a conditioned stimulus that was previously associated with an unconditioned stimulus. If extinction is considered to be a new memory, the role of the γ‐aminobutyric acid system ( GABA ergic system) during extinction memory consolidation should be similar to that described for the original trace. It is also accepted that negative modulation of the GABA ergic system before testing can impair extinction memory expression. However, it seems possible to speculate that inhibitory mechanisms may be required in order to acquire a memory that is inhibitory in nature. Using a combination of behavioral protocols, such as weak and robust extinction training procedures, and pharmacological treatments, such as the systemic administration of GABA A agonist (muscimol) and antagonist (bicuculline), we investigated the role of the GABA ergic system in the different phases of the extinction memory in the crab Neohelice granulata . We show that the stimulation of the GABA ergic system impairs and its inactivation facilitates the extinction memory consolidation. Moreover, fine variations in the GABA ergic tone affect its expression at testing. Finally, an active GABA ergic system is necessary for the acquisition of the extinction memory. This detailed description may contribute to the understanding of the role of the GABA ergic system in diverse aspects of the extinction memory.