Dopamine D.sub.2-Like Receptors Modulate Unconditioned Fear: Role of the Inferior Colliculus

A reduction of dopamine release or D.sub.2 receptor blockade in the terminal fields of the mesolimbic system clearly reduces conditioned fear. Injections of haloperidol, a preferential D.sub.2 receptor antagonist, into the inferior colliculus (IC) enhance the processing of unconditioned aversive inf...

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Bibliographic Details
Published in:PloS one 2014-08, Vol.9 (8)
Main Authors: de Oliveira, Amanda Ribeiro, Colombo, Ana Caroline, Muthuraju, Sangu, Almada, Rafael Carvalho, Brandão, Marcus Lira
Format: Article
Language:English
Subjects:
Dopamine
Haloperidol
Integrated circuits
Phenols (Class of compounds)
Online Access:Get full text
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Summary:A reduction of dopamine release or D.sub.2 receptor blockade in the terminal fields of the mesolimbic system clearly reduces conditioned fear. Injections of haloperidol, a preferential D.sub.2 receptor antagonist, into the inferior colliculus (IC) enhance the processing of unconditioned aversive information. However, a clear characterization of the interplay of D.sub.2 receptors in the mediation of unconditioned and conditioned fear is still lacking. The present study investigated the effects of intra-IC injections of the D.sub.2 receptor-selective antagonist sulpiride on behavior in the elevated plus maze (EPM), auditory-evoked potentials (AEPs) to loud sounds recorded from the IC, fear-potentiated startle (FPS), and conditioned freezing. Intra-IC injections of sulpiride caused clear proaversive effects in the EPM and enhanced AEPs induced by loud auditory stimuli. Intra-IC sulpiride administration did not affect FPS or conditioned freezing. Dopamine D.sub.2 -like receptors of the inferior colliculus play a role in the modulation of unconditioned aversive information but not in the fear-potentiated startle response.
ISSN:1932-6203
1932-6203
DOI:10.1371/journal.pone.0104228