Transcript Document

Dopaminergic Correlates of
Sensory-Specific Satiety in the
Medial Prefrontal Cortex and
Nucleus Accumbens of the Rat
Ahn & Phillips
Journal of Neuroscience 1999
Department of Psychology
University of British Columbia
“Big Picture” Questions
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Why do we eat? Why do we stop eating?
Why do we prefer certain foods?
How do we learn what we prefer?
Why do we sometimes reject certain foods
but in other circumstances we eat it?
• How does our state of hunger affect what
and how much we eat?
• What regions of the brain are involved?
• What neurotransmitters are involved?
Background Information
Part 1: Sensory Specific Satiety
• Phenomenon described in 1980’s by Rolls and colleagues
Meal 1 to
Satiety
Food A
Food A
Meal 2
offered
Food A
(same)
Food B
(different)
Response to
Meal 2
Not eat
EAT
•Now want to know the mechanism of SSS
Background Information
Part 1: Sensory Specific Satiety
• Rolls 1986
– Reported: Firing rates in neurons of
orbitofrontal lobe of monkeys change in
response to specific tastes and satiety signals
– Concluded: This region of brain is involved is
some aspect of SSS
Background Information
Part 1: Sensory Specific Satiety
• Rolls 1999 (book)
– Many steps between the sensory processing of taste and
the motivation to eat or stop eating
– Orbitofrontal cortex is believed to be involved in
motivation
• Ahn & Phillips (this paper)
– Predict that feeding behaviors will be correlated with
changes in neuronal activity in the corresponding
region of the rat brain [medial prefrontal cortex
(mPFC)]
Background Information
Part 2: The Role of Dopamine
Microdialysis probe
Source: www.chemistry.emory.edu/. ../microdialysis.htm
Source: www.chemistry.emory.edu/. ../microdialysis.htm
Source: http://utopia.utexas.edu/project/brainwaves/courses/neuro/images/NBA-VI-050123-001.gif