PMID- 25101542
OWN - NLM
STAT- MEDLINE
DCOM- 20150526
LR  - 20211021
IS  - 1872-7549 (Electronic)
IS  - 0166-4328 (Print)
IS  - 0166-4328 (Linking)
VI  - 274
DP  - 2014 Nov 1
TI  - The effects of nucleus accumbens mu-opioid and adenosine 2A receptor stimulation 
      and blockade on instrumental learning.
PG  - 84-94
LID - S0166-4328(14)00496-3 [pii]
LID - 10.1016/j.bbr.2014.07.047 [doi]
AB  - Prior research has shown that glutamate and dopamine receptors in the nucleus 
      accumbens (NAcc) core are critical for the learning of an instrumental response 
      for food reinforcement. It has also been demonstrated that mu-opioid and adenosine 
      A2A receptors within the NAcc impact feeding and motivational processes. In these 
      experiments, we examined the potential roles of NAcc mu-opioid and A2A receptors 
      on instrumental learning and performance. Sprague-Dawley rats were food 
      restricted and trained to lever press following daily intra-accumbens injections 
      of the A2A receptor agonist CGS 21680 (at 0.0, 6.0, or 24.0ng/side), the A2A 
      antagonist pro-drug MSX-3 (at 0.0, 1.0, or 3.0mug/side), the mu-opioid agonist 
      DAMGO (at 0.0, 0.025, or 0.025mug/side), or the opioid receptor antagonist 
      naltrexone (at 0.0, 2.0 or 20.0mug/side). After five days, rats continued training 
      without drug injections until lever pressing rates stabilized, and were then 
      tested with a final drug test to assess potential performance effects. 
      Stimulation, but not inhibition, of NAcc adenosine A2A receptors depressed lever 
      pressing during learning and performance tests, but did not impact lever pressing 
      on non-drug days. Both mu-opioid receptor stimulation and blockade inhibited 
      learning of the lever-press response, though only naltrexone treatment caused 
      impairments in lever-pressing after the task had been learned. The effect of A2A 
      receptor stimulation on learning and performance were consistent with known 
      effects of adenosine on effort-related processes, whereas the pattern of lever 
      presses, magazine approaches, and pellet consumption following opioid receptor 
      manipulations suggested that their effects may have been driven by drug-induced 
      shifts in the incentive value of the sugar reinforcer.
CI  - Copyright (c) 2014 Elsevier B.V. All rights reserved.
FAU - Clissold, Kara A
AU  - Clissold KA
AD  - Department of Psychology, Wake Forest University, Winston-Salem, NC, United 
      States. Electronic address: kaclissold@gmail.com.
FAU - Pratt, Wayne E
AU  - Pratt WE
AD  - Department of Psychology, Wake Forest University, Winston-Salem, NC, United 
      States. Electronic address: prattwe@wfu.edu.
LA  - eng
GR  - R15 DA030618/DA/NIDA NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
DEP - 20140804
PL  - Netherlands
TA  - Behav Brain Res
JT  - Behavioural brain research
JID - 8004872
RN  - 0 (Analgesics, Opioid)
RN  - 0 (Narcotic Antagonists)
RN  - 0 (Purinergic P1 Receptor Agonists)
RN  - 0 (Receptor, Adenosine A2A)
RN  - 0 (Receptors, Opioid, mu)
RN  - 100929-53-1 (Enkephalin, Ala(2)-MePhe(4)-Gly(5)-)
RN  - 5S6W795CQM (Naltrexone)
SB  - IM
MH  - Analgesics, Opioid/pharmacology
MH  - Animals
MH  - Conditioning, Operant/drug effects/*physiology
MH  - Dose-Response Relationship, Drug
MH  - Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
MH  - Male
MH  - Microinjections
MH  - Naltrexone/pharmacology
MH  - Narcotic Antagonists/pharmacology
MH  - Nucleus Accumbens/drug effects/*metabolism
MH  - Purinergic P1 Receptor Agonists/pharmacology
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Receptor, Adenosine A2A/*metabolism
MH  - Receptors, Opioid, mu/*metabolism
MH  - Time Factors
PMC - PMC4181594
MID - NIHMS620507
OTO - NOTNLM
OT  - Adenosine
OT  - Learning
OT  - Motivation
OT  - Nucleus accumbens
OT  - mu-Opioid receptor
EDAT- 2014/08/08 06:00
MHDA- 2015/05/27 06:00
PMCR- 2015/11/01
CRDT- 2014/08/08 06:00
PHST- 2014/02/17 00:00 [received]
PHST- 2014/06/10 00:00 [revised]
PHST- 2014/07/25 00:00 [accepted]
PHST- 2014/08/08 06:00 [entrez]
PHST- 2014/08/08 06:00 [pubmed]
PHST- 2015/05/27 06:00 [medline]
PHST- 2015/11/01 00:00 [pmc-release]
AID - S0166-4328(14)00496-3 [pii]
AID - 10.1016/j.bbr.2014.07.047 [doi]
PST - ppublish
SO  - Behav Brain Res. 2014 Nov 1;274:84-94. doi: 10.1016/j.bbr.2014.07.047. Epub 2014 
      Aug 4.