TABLE 4

Individual and mean ED50 values for the effects of pretreatment with dopamine receptor agonists on self-administration behavior during i.v. saline availability Values for each drug show the i.m. doses of dopamine receptor agonists calculated to engender 50% responding on the injection-lever, to decrease response rates to 50% of control values, and to decrease the number of food pellet deliveries to 50% of control values. Control values for each drug were the average of values for the effects of saline pretreatment during at least three sessions of i.v. saline availability during testing with that drug. Mean values are calculated only when data are available in three or four monkeys. Values in parentheses show 95% confidence limits for the means.


Pretreatment

ED50 Values
M-211
M-258
M-263
M-331
Mean (95% CL)
D1 agonists
SKF 82958
   Percentage of injection-lever 0.30 0.74 0.21 0.37 (0.08, 1.81)
   Food intake 0.34 0.68 0.20 0.36 (0.08, 1.65)
   Response rate 0.28 1.10 0.66 0.23 0.46 (0.14, 1.50)
R-(+)-6-BrAPB
   Percentage of injection-lever 0.15 0.49 0.17 0.23 (0.05, 1.17)
   Food intake 0.08 0.32 0.33 0.13 0.18 (0.06, 0.55)
   Response rate 0.11 0.44 0.20 0.21 (0.04, 1.20)
SKF 83959
   Percentage of injection-lever 0.18 0.59 0.21 0.28 (0.06, 1.40)
   Food intake 0.10 0.58 0.66 0.59 0.39 (0.09, 1.64)
   Response rate 0.12 1.1 0.41 0.14 0.30 (0.06, 1.53)
D2 agonists
Quinelorane
   Percentage of injection-lever 0.03 0.01
   Food intake 0.02 0.01 0.03 0.04 0.02 (0.01, 0.06)
   Response rate 0.02 0.06 0.003 0.54 0.04 (0.001, 1.2)
R-NPA
   Percentage of injection-lever 0.002 0.004
   Food intake 0.002 0.004 0.002 0.02 0.004 (0.001, 0.02)
   Response rate 0.002 0.01 0.001 0.01 0.004 (0.001, 0.02)
(+)-PHNO
   Percentage of injection-lever 0.001 0.001
   Food intake 0.004 0.001 0.002 0.006 0.001 (0.0001, 0.01)
   Response rate 0.001 0.002 0.001 0.003 0.002 (0.0001, 0.01)
PD 128,907
   Percentage of injection-lever 0.02 0.05
   Food intake 0.02 0.05 0.15 >0.32 0.05 (0.004, 0.65)
   Response rate
0.02
>0.32
0.07
0.02
0.03 (0.005, 0.18)