Temporary inactivation of the nucleus accumbens disrupts acquisition and expression of fear-potentiated startle in rats.
Recent research suggests that in addition to its prominent role in appetitive learning, the nucleus accumbens (NAC) may also be involved in fear conditioning. In the present study, we investigated whether temporary inactivation of the NAC, by injection of tetrodotoxin (TTX), affects acquisition and expression of conditioned fear, as measured by fear-potentiated startle (FPS). TTX injection into the NAC totally blocked acquisition and markedly decreased expression of conditioned fear to a discrete visual conditioned stimulus (CS). Interestingly, temporary inactivation of the NAC did not affect shock sensitization of startle, indicating that both the perception of the shock and short-term contextual conditioning was not affected by intra-accumbal TTX injection. Taken together, these results show that the NAC is crucial for acquisition and expression of long-term conditioned fear, as measured by fear-potentiated startle, to discrete CSs, but not short-term conditioned fear to a context.
Schwienbacher
Isabel
I
Animal Physiology, University of Tuebingen, Auf der Morgenstelle 28, D-72076 Tuebingen, Germany. isabel_schwienbacher@gmx.de
Fendt
Markus
M
Richardson
Rick
R
Schnitzler
Hans-Ulrich
HU
D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D003214:Conditioning, Classical / Q000187:drug effects* / Q000502:physiology; D005239:Fear; D008297:Male; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D013216:Reflex, Startle / Q000187:drug effects* / Q000502:physiology; D013779:Tetrodotoxin / Q000494:pharmacology*
D000779:Anesthetics, Local; D013779:Tetrodotoxin