TY - JOUR
T1 - Effects of excitotoxic lesions of the basolateral amygdala on cocaine-seeking behavior and cocaine conditioned place preference in rats
AU - Fuchs, Rita A.
AU - Weber, Suzanne M.
AU - Rice, Heather J.
AU - Neisewander, Janet
N1 - Funding Information:
The authors would like to thank Winston Villegas, Jonathan Bellew, Dawnia Zitzman, Jeff Burmeister, Breanna Bullock and Andrea Alleweireldt for technical assistance, and Drs. Peter Killeen, Cheryl Conrad and Edward Castañeda for their comments on an earlier version of this paper. This work was supported by NIH Grant DA11064, by the Howard Hughes Medical Institute through the Biological Research Experience for Undergraduates Program, and by NIH through the Minority Access to Research Careers Program.
PY - 2002/3/1
Y1 - 2002/3/1
N2 - Incentive motivation for cocaine, elicited by cocaine-associated stimuli, is thought to be involved in craving and relapse. To examine the role of the basolateral amygdala complex (BLC) in this phenomenon, we assessed the effects of post-training BLC lesions on extinction of cocaine-seeking behavior and cocaine-conditioned place preference (CPP) and the effects of pre-training BLC lesions on acquisition of cocaine-CPP. In Experiment 1, rats were first trained to self-administer cocaine and then received bilateral infusions of the excitotoxin, N-methyl-D-aspartic acid (NMDA, 0.12 M; 0.3 μl/side), or vehicle into the BLC. They were then tested repeatedly for extinction of cocaine-seeking behavior (i.e. nonreinforced responses in the presence of cocaine-paired stimuli). Subsequently, they were trained and tested for acquisition of cocaine-CPP (i.e. increased time spent in a previously cocaine-paired, relative to a saline-paired, environment). Locomotion and compartment entries were also measured. In Experiment 2, rats were first trained and tested for cocaine-CPP, and then received NMDA or vehicle infusions into the BLC. Subsequently, they were tested repeatedly for extinction of cocaine-CPP. Post-training BLC lesions retarded extinction of cocaine-seeking behavior and cocaine-CPP, whereas pre-training lesions disrupted acquisition of cocaine-CPP. These effects did not appear to be related to changes in general activity. We suggest that pre-training BLC lesions disrupted acquisition of cocaine-CPP by impairing assignment of incentive value to cocaine-paired stimuli, whereas post-training BLC lesions disrupted extinction of cocaine-conditioned behaviors by impairing the assessment of the current incentive value of cocaine-paired stimuli.
AB - Incentive motivation for cocaine, elicited by cocaine-associated stimuli, is thought to be involved in craving and relapse. To examine the role of the basolateral amygdala complex (BLC) in this phenomenon, we assessed the effects of post-training BLC lesions on extinction of cocaine-seeking behavior and cocaine-conditioned place preference (CPP) and the effects of pre-training BLC lesions on acquisition of cocaine-CPP. In Experiment 1, rats were first trained to self-administer cocaine and then received bilateral infusions of the excitotoxin, N-methyl-D-aspartic acid (NMDA, 0.12 M; 0.3 μl/side), or vehicle into the BLC. They were then tested repeatedly for extinction of cocaine-seeking behavior (i.e. nonreinforced responses in the presence of cocaine-paired stimuli). Subsequently, they were trained and tested for acquisition of cocaine-CPP (i.e. increased time spent in a previously cocaine-paired, relative to a saline-paired, environment). Locomotion and compartment entries were also measured. In Experiment 2, rats were first trained and tested for cocaine-CPP, and then received NMDA or vehicle infusions into the BLC. Subsequently, they were tested repeatedly for extinction of cocaine-CPP. Post-training BLC lesions retarded extinction of cocaine-seeking behavior and cocaine-CPP, whereas pre-training lesions disrupted acquisition of cocaine-CPP. These effects did not appear to be related to changes in general activity. We suggest that pre-training BLC lesions disrupted acquisition of cocaine-CPP by impairing assignment of incentive value to cocaine-paired stimuli, whereas post-training BLC lesions disrupted extinction of cocaine-conditioned behaviors by impairing the assessment of the current incentive value of cocaine-paired stimuli.
KW - Basolateral amygdala
KW - Cocaine
KW - Cocaine-seeking behavior
KW - Conditioned place preference
KW - Incentive motivation
KW - Stimulus-reward learning
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U2 - 10.1016/S0006-8993(01)03366-2
DO - 10.1016/S0006-8993(01)03366-2
M3 - Article
C2 - 11852027
AN - SCOPUS:0036498266
SN - 0006-8993
VL - 929
SP - 15
EP - 25
JO - Brain Research
JF - Brain Research
IS - 1
ER -