Table 4

Summary of antagonist activities of SIB-1757 and SIB-1893 on cultured cortical neurons

First AdditionSecond AdditionResponders to First ChallengeResponders to Second ChallengeAverage Response Difference
n n % control
100 μM DHPG100 μM DHPG124 /124121 /12480  ± 37
(100%)(98%)
100 μM DHPG100 μM DHPG/10 μM SIB-1757147 /14831 /14845  ± 19
 (99%)(21%)
100 μM DHPG100 μM DHPG/10 μM SIB-1893129 /12970 /12953  ± 12
(100%)(54%)

Cortical neurons were challenged with 100 μM DHPG for 30 s and then washed for 3 min and rechallenged with 100 μM DHPG in the absence or presence of antagonist. The number of responders was quantified as described in the text. The average response difference was determined by calculating the peak magnitude of the responders to the second agonist and expressing it as a percentage of the peak magnitude of first agonist for each cell (mean ± S.D.).