1. Nucleus Accumbens
Pleasure Center of the Brain
Friday, October 18, 13

2. Location in the brain:
Friday, October 18, 13

3. Functions:
•Motivation and Reward
•Addiction
•Laughter
•Pleasure
•Fear
•Placebo Effect
Works on: Dopamine and Serotonin
Friday, October 18, 13

4. Three Studies:
James Oldes and Peter Milner (1950s)
Schaepfer, Sackeim, Luber et al. (2007)
Nikolai Axmacher (2010)
Friday, October 18, 13

5. Oldes & Milner (1950s)
Aim: Determine how rats would respond to the
opportunity of stimulating their pleasure centers
by pushing a lever.
Friday, October 18, 13

6. Oldes & Milner (1950s)
Procedure:
•Implanted electrodes
into the rats.
•Each time they pressed
the lever, they would
receive an electric
shock to their nucleus
accumbens.
Friday, October 18, 13

7. Oldes & Milner (1950s)
Results + Findings:
•The rats became addicted with pressing the lever.
•They preferred pressing the lever to eating or
drinking -- Many starved themselves.
•They ran across the electrified grid to reach the lever.
Friday, October 18, 13

8. Sackeim, Luber et al. (2007)
Aim: Treat severely depressed patients who
have not responded to treatment, with deep
brain stimulation.
Friday, October 18, 13

9. Sackeim, Luber et al. (2007)
Procedure:
•Implanted electrodes
into the nucleus
accumbens of the
depressed patients.
•Turned on the
stimulator, which sent
electrical signals to the
pleasure centers.
•Turned the stimulator
on and off over a
period of a few weeks.
Friday, October 18, 13

10. Sackeim, Luber et al. (2007)
Results and Findings:
•Most results showed that it was effective short
term, but not long term.
•It produced short term pleasure, instant
gratification that did not last.
•Did not treat long term depression
•Some patients found more motivation right after
the stimulation.
Friday, October 18, 13

11. Axmacher (2010)
Aim: The relation between the nucleus accumbens
and the formation of surprising events
Friday, October 18, 13

12. Axmacher (2010)
Procedure:
•Implanted electrodes in
the nucleus accumbens
and the hippocampus.
•Showed participants
various images
•ie. Face on red
background and house
on green background
•Used EEG to see brain
patterns
Friday, October 18, 13

13. Axmacher (2010)
Results + Findings:
•Switching the images activated the two different
areas of the brain
•The hippocampus, to the nucleus accumbens,
back to the hippocampus.
•Allows prediction of memory formation.
•The pleasure centers do not only activate
‘pleasurable’ memories, but also responds to bad
experiences.
•Something scary can release dopamine.
Friday, October 18, 13

14. Dysfunctions
•Depression
•Drug Addiction
•Tourette Syndrome
•ADHD
•Impulsive Choice
•Lack of Motivation
Friday, October 18, 13

15. Depression
•NAc role in pathophysiology of
depression
•Hypothesized that adhedonia produced
from NAc dysfunction
•Stress, Drugs produce depressive
phenotype->
•Change functions in NAc->
•Inhibited Dopaminergic activity in NAc
Friday, October 18, 13

16. Work Cited
Hanson, Dirk. "Addiction Inbox: The Nucleus Accumbens." Addiction Inbox. N.p., n.d. Web. 18
Oct. 2013. <http://addiction-dirkh.blogspot.com/2010/02/nucleus-accumbens.html>.
"How does the reward center in the brain work? - Curiosity." Curiosity : Discovery Channel. N.p.,
n.d. Web. 16 Oct. 2013. <http://curiosity.discovery.com/question/reward-center-in-brain-work>.
"NIMH · Brain Stimulation Therapies."NIMH · Home. N.p., n.d. Web. 17 Oct. 2013. <http://
www.nimh.nih.gov/health/topics/brain-stimulation-therapies/brain-stimulationtherapies.shtml#Lisanby>.
"Science Daily." Science Daily. N.p., n.d. Web. 16 Oct. 2013. <www.sciencedaily.com>.
"THE BRAIN FROM TOP TO BOTTOM."Brain from top to bottom. N.p., n.d. Web. 17 Oct. 2013.
<http://thebrain.mcgill.ca/flash/i/i_03/i_03_cr/i_03_cr_par/i_03_cr_par.html>
"What is the nucleus accumbens? - Functions of the Brain - Sharecare."Expert Health
Information - Questions and Answers - Sharecare. N.p., n.d. Web. 16 Oct. 2013. <http://
www.sharecare.com/health/functions-of-the-brain/what-is-the-nucleus-accumbens>.
" This Strange Experiment from the 1950s. Motherboard | Home | Motherboard. N.p., n.d. Web.
16 Oct. 2013. <http://motherboard.vice.com/read/wireheading-1950s-wetware-hacking>.
Friday, October 18, 13