PMID- 17019568
OWN - NLM
STAT- MEDLINE
DCOM- 20070302
LR  - 20181113
IS  - 0033-3158 (Print)
IS  - 0033-3158 (Linking)
VI  - 189
IP  - 4
DP  - 2007 Jan
TI  - Reinforcement schedule effects in rats trained to discriminate 
      3,4-methylenedioxymethamphetamine (MDMA) or cocaine.
PG  - 447-57
AB  - RATIONALE: Relatively few studies have compared the discriminative stimulus 
      effects of 3,4-methylenedioxymethamphetamine (MDMA) and cocaine, and findings 
      from different laboratories are somewhat inconsistent. One possible reason for 
      discrepant results may be the use of different reinforcement schedules during 
      discrimination training. OBJECTIVE: The present study compared fixed ratio (FR) 
      20 and variable interval (VI) 15-s reinforcement schedules to determine their 
      influence on discrimination acquisition, response rates, frequency of 
      reinforcements, and stimulus generalization in rats trained to discriminate 
      cocaine or MDMA. MATERIALS AND METHODS: Thirty-two male Sprague-Dawley rats were 
      trained to discriminate cocaine (10 mg/kg; n=16) or MDMA (1.5 mg/kg; n=16) from 
      saline under either a FR 20 or a VI 15-s schedule of food reinforcement. Stimulus 
      generalization tests were conducted with a range of doses of cocaine, MDMA, 
      d-amphetamine, and lysergic acid diethylamide in all four training groups. 
      RESULTS: The FR 20 schedule facilitated more rapid discrimination acquisition 
      compared to the VI 15-s schedule and established differential response rates and 
      frequency of reinforcement under drug and vehicle conditions. However, 
      reinforcement schedule had little influence on stimulus generalization between 
      MDMA and cocaine. Cocaine produced partial substitution for MDMA in both training 
      groups (FR 20, 51%; VI 15-s, 58%). Likewise, MDMA produced only partial 
      substitution for cocaine in both training groups (FR 20, 40%; VI 15-s, 72%). 
      CONCLUSIONS: The present findings suggest that the number of sessions required to 
      establish discriminative stimulus control varies with different reinforcement 
      schedules. Nevertheless, training schedules alone do not appear to have 
      significant effects on stimulus generalization between MDMA and cocaine.
FAU - Kueh, Daniel
AU  - Kueh D
AD  - Department of Biological Sciences, Western Michigan University, Kalamazoo, MI 
      49008, USA.
FAU - Baker, Lisa E
AU  - Baker LE
LA  - eng
PT  - Comparative Study
PT  - Journal Article
DEP - 20060923
PL  - Germany
TA  - Psychopharmacology (Berl)
JT  - Psychopharmacology
JID - 7608025
RN  - 0 (Central Nervous System Stimulants)
RN  - 0 (Hallucinogens)
RN  - 8NA5SWF92O (Lysergic Acid Diethylamide)
RN  - I5Y540LHVR (Cocaine)
RN  - KE1SEN21RM (N-Methyl-3,4-methylenedioxyamphetamine)
RN  - TZ47U051FI (Dextroamphetamine)
SB  - IM
MH  - Animals
MH  - Behavior, Animal/*drug effects
MH  - Central Nervous System Stimulants/*administration & dosage
MH  - Cocaine/*administration & dosage
MH  - Dextroamphetamine/administration & dosage
MH  - Discrimination Learning/*drug effects
MH  - Dose-Response Relationship, Drug
MH  - Generalization, Stimulus/drug effects
MH  - Hallucinogens/*administration & dosage
MH  - Lysergic Acid Diethylamide/administration & dosage
MH  - Male
MH  - N-Methyl-3,4-methylenedioxyamphetamine/*administration & dosage
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - *Reinforcement Schedule
MH  - Time Factors
EDAT- 2006/10/05 09:00
MHDA- 2007/03/03 09:00
CRDT- 2006/10/05 09:00
PHST- 2005/12/10 00:00 [received]
PHST- 2006/07/21 00:00 [accepted]
PHST- 2006/10/05 09:00 [pubmed]
PHST- 2007/03/03 09:00 [medline]
PHST- 2006/10/05 09:00 [entrez]
AID - 10.1007/s00213-006-0523-z [doi]
PST - ppublish
SO  - Psychopharmacology (Berl). 2007 Jan;189(4):447-57. doi: 
      10.1007/s00213-006-0523-z. Epub 2006 Sep 23.