Figure 3.

Intrinsic excitability examples in hippocampal interneurons

(A) Induction mechanisms of synaptically generated LTP-IE in PV BCs in the CA1 after activation of CA3 Schaffer-collateral inputs (high-frequency stimulation). Top: graphical illustration of the experimental protocol and main findings. Induction of intrinsic excitability in CA1 FS BCs resulted in: (i) higher spiking activity and reduced first spike latency (iii). (ii) Shows the spike timing over time in a representative example (n = 9 FS BCs, scale bars: 200 ms and 40 mV).

(B) Induction of presynaptic LTD in CA1 O-LM interneurons triggers a Kv7 potassium channel dependent decrease in their intrinsic excitability. Top: graphical illustration of the experimental design and findings. (i) The induction of presynaptic LTD was induced via a protocol of negative pairing between a single postsynaptic action potential, followed by a presynaptic (pyramidal) stimulation with a delay of 5, 10, or 20 Hz. Negative pairing at 10 Hz induces presynaptic LTD (measured as changes in the EPSP slope) and (ii) and decreases in the intrinsic excitability (measured as changes in the number of spikes) (iii) in CA1 O-LM interneurons. Pooled data. (A) Campanac et al.¹¹⁹ and (B) Incontro et al.¹²¹ modified with permission.