Whole-cell recording from Kenyon cells in silkmoths

Kenyon cells (KCs), which are present in the mushroom bodies (MBs) of the insect brain, play an important role in olfactory information processing and associative learning. However, the intrinsic electrophysiological properties of KCs in silkmoth (Bombyx mori) MBs remain unknown. Here, we use whole-cell patch-clamp recordings to elucidate the functional parameters of membrane voltage and voltage-activated ionic currents of KCs in silkmoth MBs. KCs generated action potentials in response to stepping pulses of depolarizing current, and application of GABA-receptor blocker abolished inhibitory synaptic inputs and depolarized resting membrane potential. Pharmacological isolation of KC voltage-gated ionic currents revealed that KCs express a range of voltage-activated channels, including transient and non-inactivating potassium, sodium, and calcium channels. Our results provide the first electrophysiological characterization of KCs in silkmoth MBs and represent an important step toward understanding neuronal computation that underlies olfactory information processing in silkmoths.