the effect of caffeine on neurological dopamine production process dynamics & control october 13...
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The Effect of Caffeine on Neurological Dopamine Production
Process Dynamics & ControlOctober 13th, 2004Student Name 1Student Name 2
Presentation Outline
Introduction Simulation Assumptions Process Outcomes
Laplace via Maple Matlab Simulink
Conclusion
What is Caffeine?
The most commonly used neurological drug worldwide
trimethylxanthine, (C8H10N4O2) bitter tasting white powder
Retrieved from: www.cs.virginia.edu/.../ caffeine-molecule.gif
Common Substances
Coffee, tea, soft drinks, and pain medication
Caffeine Content: Brewed coffee: 40-180 mg Black Tea: 20-100 mg Excedrin: 65 mg Mountain Dew: 55 mg Green Tea: 8-36 mg
What is Dopamine?
Neurotransmitter Movement Thought processes Emotions Pleasure “Rewards” centers of the brain
Retrieved from: http://www.bip.bham.ac.uk/osmart/msctox/
The Relationship Between Caffeine and Dopamine
Caffeine has ½ life of ~6 hours in a healthy person
Enters Digestive tract Some caffeine is lost in liver Remainder enters bloodstream
Caffeine enters the brain Stimulates excessive dopamine release Blocks uptake receptors
Simulation Assumptions
Body consists of 3 tanks Stomach, Liver, and Brain
Flow rates, tank volumes and density remain constant
Dopamine production is a first order chemical reaction Caffeine→Dopamine
Initial Conditions
F1 25 dL/s
F2 20 dL/s
F3 0.0001 dL/s
F4 0.0001 dL/s
F5 0.05 dL/s
k1 0.250 mol-dL-1s-1
k2 0.125 mol-dL-1s-1
Vs 5 dL
Vl 4 dL
Vb 2 dL
Simulation Process
Ci,caf., F1
Stomach: C1, Vs
F2, C1
C3, F3, D3
Liver: D2, C2, Vl
Brain:D5, C5, Vb
F4, C4, D4
F5, D5
Caffeine Dopamine rb=k1C5
Mass Balances: Stomach
Ci,caf., F1
Stomach: C1, Vs
F2, C1
Equation 1. Stomach Mass Balance (Caffeine)
12,11 CFCF
dt
dCV cafis
Mass Balance: Liver
F2, C1
C3, F3, D3
Liver: D2, C2, Vl
F4, C4, D4
F5, D5
3344122 CFCFCF
dt
dCVl
4433552 DFDFDF
dt
dDVl
Equation 2. Liver Mass Balance (Caffeine)
Equation 3. Liver Mass Balance (Dopamine)
Mass Balance: Brain
Brain:D5, C5, Vb
F4, C4, D4
F5, D5
Caffeine Dopamine rb=k1C5
51445 CkCF
dt
dCVb
5255445 CkDFDF
dt
dDVb
Equation 4. Brain Mass Balance (Caffeine)
Equation 5. Brain Mass Balance (Dopamine)
Laplace Transform: Steady State
025.0105.2
105.20125.0
115.0
1075.3105.2
0125.01
025.0
0625.0
15.0
1075.3
105.2
5
4
5
)()('5
5
5
5
5
5
,5
sx
xssx
xs
ss
x
xsssCsD cafi
S-Domain
t-Domain
=Ci,caf{
}
Caffeine Impulse Function
0 100 200 300 400 500 600 700 800 900 10000
5
10
15
20
25
30
35
40
45
time,seconds
conc
entr
atio
n,C
affe
ine
Caffeine Impulse
C in Stomach
C in LiverC in Brain
Caffeine Unit Step Function
0 100 200 300 400 500 600 700 800 900 10000
5
10
15
20
25
30
35
40
45
time,seconds
conc
entr
atio
n,C
affe
ine
Caffeine Step Function
C in Stomach
C in LiverC in Brain
Caffeine at Steady-State
0 100 200 300 400 500 600 700 800 900 10000
5
10
15
20
25
30
35
40
45
time,seconds
conc
entr
atio
n,C
affe
ine
Caffeine at Steady State
C in Stomach
C in LiverC in Brain
Dopamine at Steady State
0 100 200 300 400 500 600 700 800 900 10000
10
20
30
40
50
60
70
time,seconds
conc
entr
atio
n,do
pam
ine
Dopamine at Steady State
D in Brain
D in Liver
Dopamine Unit Step Function
0 200 400 600 800 1000 1200 1400 1600 1800 20000
10
20
30
40
50
60
70
time,seconds
conc
entr
atio
n,do
pam
ine
Dopamine Unit Step Function
D in Brain
D in Liver
Dopamine Impulse Function
0 500 1000 1500 2000 25000
10
20
30
40
50
60
70
time,seconds
conc
entr
atio
n,do
pam
ine
Dopamine Impulse
D in Brain
D in Liver
Conclusion
Achieved anticipated results in the theoretical process
Possible differences in real process Suggestions Thanks to Dr. Rodgers