Figure 4.

Activity of CA1 local interneurons during theta and ripple oscillations

(A) Most relevant interneuron types in CA1 separated by morphology and molecular markers. For reference, the somatodendritic layout of a schematic pyramidal cell (PC, left) is included. Note that for three interneuron subtypes, two separate morphological subclasses have been described.

(B–D) Properties of the interneuron classes displayed in (A), during theta oscillations (upper row) and ripples (lower row). Data were obtained from different studies (a–i), with the following experimental conditions: (a) anesthetized rat²²; (b) anesthetized rat¹⁶²; (c) freely moving rat¹⁵; (d) awake head-fixed mouse²³; (e) anesthetized and freely moving rat²¹; (f) freely moving rat¹⁶; (g) awake head-fixed mouse²⁴ (for PV BCs: black, population average, [g1, green] vertical and [g2, yellow] horizontal orientation; for AACs: two individual horizontal cells reported [g2, yellow]; for BiCs: black, population average, [g1, green], “classical” and [g2, yellow] “oriens” orientation); (h) awake head-fixed mouse¹⁴; (i) awake head-fixed mouse.²⁰ (B) Spike rates. Note that the reported spike rates might differ, even for a given interneuron subtype, depending on the experimental conditions. In some studies, individual neurons were reported and therefore no error margins are displayed. (C) Preferred spike phases. Phase values are given with a full cycle of oscillations as a reference. (D) Modulation strength, reflecting how precisely the spikes of a cell are bound to a particular phase of an oscillation with values ranging from 0 (no preferred spike phase) to 1 (all spikes occur with the same phase angle). The error bars shown represent the margins of error reported in the indicated studies.