Figure 5.

Removal of Mg²⁺ from the saline abolished both NMDA-induced repetitive firing and TTX-resistant oscillations in dINs. A, In saline containing Mg²⁺, dIN fired repetitively to current injection during NMDA application. B, When NMDA leads to larger depolarization, dIN also fires repetitively. C, When Mg²⁺ was removed from saline, the dIN only fired once to current injection during NMDA application. D, In 0 Mg²⁺, another dIN failed to fire any spikes when depolarized only by NMDA. E, In 0 Mg²⁺ and TTX, NMDA application did not evoke oscillations in a dIN even during negative current injection. a–c records are expanded.