Figure 5.

Precise capacitance compensation is required for boutons current-clamp recordings

(A) Example soma action potentials recorded without compensation of pipette capacitance (ø Cap. comp), with compensation of the capacitance value determined in voltage-clamp mode (±0 pF), and with small undercompensation (-0.25 pF, -0.5 pF) and overcompensation (+0.25 pF, +0.5 pF) of pipette capacitance. Note the small sensitivity of somatic action potential shape to changes in pipette capacitance compensation.

(B) Example bouton action potentials recorded with varying pipette capacitance compensation as in (A). Note the strong effect of small deviations in capacitance compensation on the bouton action potential amplitude and duration.

(C) Increasing pipette capacitance compensation in current-clamp mode in a circuit model of a neuronal soma leads to voltage oscillations separable from slower voltage changes across the somatic capacitance. Box: Expansion of the initial current injection-evoked voltage change for different pipette capacitance compensations.

(D) Current injection-evoked voltage responses in a circuit model of a bouton for different pipette capacitance compensations. Box: Expansion of the initial current injection-evoked voltage changes. Panels (C and D) were modified from Ritzau-Jost et al. (2021).¹