1. Delayed Spatial Alternation

2. Delayed Spatial Alternation

3. Neural recording Male Wistar rats 14-tetrode hyperdrive Single units and LFP Right CA1 area (AP -3.6, ML 2.2 mm)

4. Delayed Spatial Alternation

8. From rate coding Fixation-specific firing Not movement-related, not sensory A more complex, abstract code Sequence-dependent in the spatial alternation task

9. Relating spikes to theta oscillation...

10. Theta phase shift Single trial examples Blue line = LFP trace (6-10 Hz filtered) Red circles = spikes Gray zone = the fixation period

11. Population trend of phase shift during fixation First: Spikes at theta peak Then: Spikes at theta trough

12. What about gamma oscillation?

13. The gamma shift is also anchored on the theta oscillation: First: high gamma at theta peak Then: Low gamma at theta trough

14. Shifts of information processing From external to internal mode, From high gamma to low gamma, From theta peak to theta trough