PMID- 26888930
OWN - NLM
STAT- MEDLINE
DCOM- 20160629
LR  - 20220309
IS  - 1529-2401 (Electronic)
IS  - 0270-6474 (Print)
IS  - 0270-6474 (Linking)
VI  - 36
IP  - 7
DP  - 2016 Feb 17
TI  - Phasic Dopamine Transmission Reflects Initiation Vigor and Exerted Effort in an 
      Action- and Region-Specific Manner.
PG  - 2202-11
LID - 10.1523/JNEUROSCI.1279-15.2016 [doi]
AB  - Initiating a reward-seeking behavior involves deciding on an action, how fast to 
      initiate the action (initiation vigor), as well as how much effort to exert. 
      These processes are thought to involve the mesolimbic dopamine system. Dopamine 
      levels in the ventral striatum rise before initiating a reliably reinforced 
      behavior. However, it is unknown whether dopamine is similarly involved with 
      unreinforced actions (inactive lever presses, premature food port entries, 
      insufficient number of active lever presses). Furthermore, does the dopamine 
      response when initiating an action reflect specific aspects of motivated 
      behavior, such as initiation vigor and exerted effort? Here, we analyzed 
      voltammetry recordings of dopamine levels in the nucleus accumbens (NAcc) core 
      and shell in rats working for food under a progressive ratio reinforcement 
      schedule. We examined dopamine levels when rats initiated distinct actions 
      (active lever presses, inactive lever presses, food port entries) that were 
      temporally separated from cue- and reward-evoked dopamine release. Active lever 
      pressing bouts were preceded by elevated dopamine release in the NAcc shell, as 
      well as in the NAcc core, although only when rats exhibited high initiation 
      vigor. Dopamine levels were transiently reduced in the NAcc core following an 
      unreinforced food port entry and were unchanged throughout the NAcc when 
      initiating inactive lever presses. The effort exerted and vigor to initiate a 
      bout of active lever presses were signaled by dopamine transmission in the NAcc 
      core, but not in the NAcc shell. These results demonstrate that the dopamine 
      response when initiating a behavior is both region- and action-specific. 
      SIGNIFICANCE STATEMENT: Exogenous activation of the mesolimbic dopamine system 
      facilitates motivated behavior. However, a direct relationship has not been 
      established between endogenous phasic dopamine transmission and measures of 
      motivation, such as the vigor to initiate an action and the effort exerted in a 
      bout of activity. The present work demonstrates that the dopamine response when 
      initiating an action depends both upon where dopamine is released and what action 
      is performed. Furthermore, dopamine reflects measures of motivated behavior 
      selectively within the nucleus accumbens core.
CI  - Copyright (c) 2016 the authors 0270-6474/16/362202-10$15.00/0.
FAU - Ko, Daijin
AU  - Ko D
AD  - Department of Management Science and Statistics and.
FAU - Wanat, Matthew J
AU  - Wanat MJ
AUID- ORCID: 0000-0003-1643-6557
AD  - Neurosciences Institute and Department of Biology, University of Texas at San 
      Antonio, San Antonio, Texas 78249 Matthew.wanat@utsa.edu.
LA  - eng
GR  - K99 DA033386/DA/NIDA NIH HHS/United States
GR  - R00 DA033386/DA/NIDA NIH HHS/United States
GR  - DA033386/DA/NIDA NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PL  - United States
TA  - J Neurosci
JT  - The Journal of neuroscience : the official journal of the Society for 
      Neuroscience
JID - 8102140
RN  - VTD58H1Z2X (Dopamine)
SB  - IM
MH  - Animals
MH  - Conditioning, Operant/physiology
MH  - Cues
MH  - Dopamine/metabolism/*physiology
MH  - Food
MH  - Male
MH  - Motivation/physiology
MH  - Nucleus Accumbens/metabolism
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Reinforcement Schedule
MH  - Reward
MH  - Synaptic Transmission/*physiology
PMC - PMC4756155
OTO - NOTNLM
OT  - dopamine
OT  - effort
OT  - initiation vigor
OT  - motivation
OT  - nucleus accumbens
OT  - voltammetry
EDAT- 2016/02/19 06:00
MHDA- 2016/06/30 06:00
PMCR- 2016/08/17
CRDT- 2016/02/19 06:00
PHST- 2016/02/19 06:00 [entrez]
PHST- 2016/02/19 06:00 [pubmed]
PHST- 2016/06/30 06:00 [medline]
PHST- 2016/08/17 00:00 [pmc-release]
AID - 36/7/2202 [pii]
AID - 1279-15 [pii]
AID - 10.1523/JNEUROSCI.1279-15.2016 [doi]
PST - ppublish
SO  - J Neurosci. 2016 Feb 17;36(7):2202-11. doi: 10.1523/JNEUROSCI.1279-15.2016.