Fig. 6.

Spatial resolution of the partialization technique. A, Effect of partialization on the str. oriens–hippocampal fissure coherence using neighboring signals recorded at 100 μm distance on either side of the str. oriens and hippocampal fissure electrodes. High theta peak present in the ordinary coherence function between hippocampal fissure (ch9) and any one of the str. oriens sites (ch3,top) was eliminated by partialization with signals recorded from within str. oriens (ch2 andch4, left) but not with signals recorded in distal str. radiatum (ch8) or dentate molecular layer (ch10, right). B, The high coherence, homogeneous in the entire 0–30 Hz range, between neighboring signals in the str. oriens were not affected by partialization with signals recorded from outside str. oriens, including that in hippocampal fissure (ch9,left). On the other hand, theta oscillations in the str. oriens explained some of the coherence between hippocampal fissure and its closest neighbors because partialization with ch3 (o) specifically decreased the coherence between ch9 (hippocampal fissure) and ch8 (str. lacunosum moleculare) at theta frequency.