Biomedical Engineering Reference
In-Depth Information
(a)
80
Reference
Bhanol (mM)
800
70
20
40
60
80
100
60
600
50
Mean spikes/minute
Mean burst /minute
40
400
30
20
200
10
0
0
0
50
100
150
200
250
Time (minutes)
(b)
50
45
Reference
160 mM
Wash
160 mM
Wash
500
40
Mean spikes/minute
Mean bursts/minute
35
400
30
300
25
20
200
15
10
100
5
0
0
0
50
100
150
200
250
Neurons averaged = 15
Time (minutes)
(c)
0
YXS
YXS
YXS
YXS
YXS
−
20
40
−
−
60
−
80
100
10
Ethanol concentration (mM)
100
1000
FIGURE 6.8
(a) Frontal cortex network response to increasing concentrations of ethanol. Each data point represents the per-
minute average of spike (open circles) and burst (closed symbols) production for all discriminated units
recorded. Percent decreases are calculated from a mean reference activity preceding all applications of test sub-
stances. In the case of slow spontaneous recovery of activity, the maximum decrease attained at a particular test
substance concentration is used for response calculations. (b) Reproducibility of recovery after exposure to high
concentrations of ethanol. (c) Concentration-response curves for five different frontal cortex networks; EC
50
: 48.8
5.4 mM (redrawn from Xia and Gross, 2003).
Recent work has shown that dissociation constants can also be determined using spon-
taneously active primary cultures on MEAs [19]. A summary for the titration of muscimol
in the presence of its antagonist gabazine is presented in Figure 6.10. Muscimol is a potent
and specific gamma-aminobutyric acid (GABA) analog [20]. Because there is no re-uptake
