TY - JOUR
T1 - Intravenous cocaine self-administration in mice lacking 5-HT1B receptors
AU - Rocha, Beatriz A.
AU - Ator, Robert
AU - Emmett-Oglesby, Michael W.
AU - Hen, Rene
N1 - Funding Information:
We thank Rachel Peltier for her technical assistance. This work was supported by grant RO1 DA 4137 (MWE-O) from the National Institute of Drug Abuse (NIDA).
PY - 1997/7
Y1 - 1997/7
N2 - The present experiment tested the hypothesis that 5-HT1B receptors are involved in the reinforcing effects of cocaine. Transgenic mice lacking 5-HT1B receptors were used as subjects and compared with wild-type mice for the acquisition and maintenance of intravenous (IV) cocaine self-administration. Male 129/Sv-ter and 5-HT1B-minus 129/Sv-ter inbred mice (Columbia University, New York) were initially trained to press a lever under a fixed-ratio schedule 2, first for sweetened condensed milk as reinforcer and subsequently for cocaine (2.0 mg/kg/infusion). When a stable baseline of responding was obtained, each subject was tested under different doses of cocaine (1.0, 2.0, and 4.0 mg/kg), with the number of reinforcers per hour used as the dependent variable. Both strains successfully acquired food-shaping and cocaine self-administration, but the mutant mice presented a significantly shorter latency to meet IV cocaine self-administration acquisition criteria (p < 0.05). However, both wild-type and mutant mice had similar dose-response to cocaine. These results suggest that the 5-HT1B receptors may be implicated in the propensity to self-administer cocaine, but other mechanisms might be involved in the maintenance of cocaine self-administration.
AB - The present experiment tested the hypothesis that 5-HT1B receptors are involved in the reinforcing effects of cocaine. Transgenic mice lacking 5-HT1B receptors were used as subjects and compared with wild-type mice for the acquisition and maintenance of intravenous (IV) cocaine self-administration. Male 129/Sv-ter and 5-HT1B-minus 129/Sv-ter inbred mice (Columbia University, New York) were initially trained to press a lever under a fixed-ratio schedule 2, first for sweetened condensed milk as reinforcer and subsequently for cocaine (2.0 mg/kg/infusion). When a stable baseline of responding was obtained, each subject was tested under different doses of cocaine (1.0, 2.0, and 4.0 mg/kg), with the number of reinforcers per hour used as the dependent variable. Both strains successfully acquired food-shaping and cocaine self-administration, but the mutant mice presented a significantly shorter latency to meet IV cocaine self-administration acquisition criteria (p < 0.05). However, both wild-type and mutant mice had similar dose-response to cocaine. These results suggest that the 5-HT1B receptors may be implicated in the propensity to self-administer cocaine, but other mechanisms might be involved in the maintenance of cocaine self-administration.
KW - 5-HT1B receptors
KW - Cocaine
KW - IV self-administration
KW - Reinforcing effects
KW - Transgenic mice
UR - http://www.scopus.com/inward/record.url?scp=0030814702&partnerID=8YFLogxK
U2 - 10.1016/S0091-3057(96)00444-3
DO - 10.1016/S0091-3057(96)00444-3
M3 - Article
C2 - 9218264
AN - SCOPUS:0030814702
SN - 0091-3057
VL - 57
SP - 407
EP - 412
JO - Pharmacology, Biochemistry and Behavior
JF - Pharmacology, Biochemistry and Behavior
IS - 3
ER -