Figure 7
Effect of chronic inhibition of GABAergic neurotransmission on the maturation of spontaneous network activity in the chicken spinal cord. GABAergic neurotransmission was disrupted in ovo by daily applications of bicuculline (20 μM/day) or muscimol (5 μM/day). Drugs were applied to the chorioallantoic membrane of chicken embryos between E5 and E8 (A-C) or between E8 and E10 (D-F). After the last drug application, embryos were removed (E8 or E10) and the spinal cord was isolated for recording of spontaneous network activity. (A) Typical example of an episode of spontaneous activity generated in a vehicle- and a bicuculline-treated spinal cord at E8. Notice that the overall shape of each episode remains the same after chronic inhibition of GABA receptor activation. (B, C) Chronic inhibition of GABAergic neurotransmission did not alter the episode duration and inter-episode interval in E8 spinal cords. (D) Overall shape of an episode of spontaneous activity generated in a vehicle- and a bicuculline-treated spinal cord at E10. Notice that the overall shape of each episode remains the same after chronic inhibition of GABA receptor activation. (E, F) Chronic inhibition of GABAergic neurotransmission did not alter the episode duration but causes a significant increase in the inter-episode interval at E10 (*P < 0.05 versus vehicle). NS denotes no significant differences between the groups as indicated by one-way ANOVA.