TY - JOUR
T1 - Dopamine D2-like receptors modulate unconditioned fear
T2 - Role of the inferior colliculus
AU - De Oliveira, Amanda Ribeiro
AU - Colombo, Ana Caroline
AU - Muthuraju, Sangu
AU - Almada, Rafael Carvalho
AU - Brandão, Marcus Lira
N1 - Funding Information:
A.R. de Oliveira holds a postdoctoral fellowship from FAPESP (Proc. no. 2010/50669-6). S. Muthuraju is a recipient of a postdoctoral scholarship from FAPESP (Proc. no. 2011/14686-6). R.C. Almada holds a postdoctoral fellowship from FAPESP (Proc. no. 2012/22681-7). A.C. Colombo holds a Master scholarship from FAPESP (Proc. no. 2012/06546-2).
PY - 2014/8/18
Y1 - 2014/8/18
N2 - Background: A reduction of dopamine release or D2 receptor blockade in the terminal fields of the mesolimbic system clearly reduces conditioned fear. Injections of haloperidol, a preferential D2 receptor antagonist, into the inferior colliculus (IC) enhance the processing of unconditioned aversive information. However, a clear characterization of the interplay of D2 receptors in the mediation of unconditioned and conditioned fear is still lacking. Methods: The present study investigated the effects of intra-IC injections of the D2 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. Results: 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. Conclusions: Dopamine D2-like receptors of the inferior colliculus play a role in the modulation of unconditioned aversive information but not in the fear-potentiated startle response.
AB - Background: A reduction of dopamine release or D2 receptor blockade in the terminal fields of the mesolimbic system clearly reduces conditioned fear. Injections of haloperidol, a preferential D2 receptor antagonist, into the inferior colliculus (IC) enhance the processing of unconditioned aversive information. However, a clear characterization of the interplay of D2 receptors in the mediation of unconditioned and conditioned fear is still lacking. Methods: The present study investigated the effects of intra-IC injections of the D2 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. Results: 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. Conclusions: Dopamine D2-like receptors of the inferior colliculus play a role in the modulation of unconditioned aversive information but not in the fear-potentiated startle response.
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U2 - 10.1371/journal.pone.0104228
DO - 10.1371/journal.pone.0104228
M3 - Article
C2 - 25133693
AN - SCOPUS:84929134820
SN - 1932-6203
VL - 9
JO - PLoS ONE
JF - PLoS ONE
IS - 8
M1 - e104228
ER -