Figure 5.

NMDA-dependent septotemporal coherence plasticity. A, Representative traces. Top, In control conditions, the septal and temporal oscillations exhibit low coherence, whereas during high [Ca]_o and the washout period, the two oscillations become highly coherent. Bottom, Representative traces from the septal and temporal oscillators in control, high [Ca]_o with AP-5, and washout period. There is a visible lack of coupling during and after [Ca²⁺]o. B, Time course of peak coherence. Solid points indicate averaged peak coherence showing the “LTP”-like effect induced by high calcium; hollow points, averaged coherence shown while NMDA channels are blocked by preapplication of AP-5 (50 μm), subsequent high calcium application failed to induce the S-T coherence potentiation. C, D, The time course of power and PLV during the high calcium (solid points) experiments or during high calcium with AP-5 (hollow points). E, Summary graph of peak coherence change by high calcium (left) or by high calcium with AP-5 (right); each group, n = 6. **p < 0.01. NS, Not significant (p > 0.05). F, Linear regression graph. Left, Coherence value 24–25 min after washout versus PLV during 3 min high calcium induction. Right, Coherence value 24–25 min after washout versus power value during 3 min high calcium induction. G, Averaged coherence showing that, after the high calcium potentiation of S-T coherence, subsequent application of NMDA channel blocker AP-5 had no significant effect on the potentiated coherence (hollowed points) compared with that without AP-5 presence (solid points).