The primary cilium is a non-motile sensory organelle that acts as a transducer of environmental cues into cellular responses. It comprises an axoneme, which is a core of microtubules (MTs), coated by a specialized membrane populated by receptors and a high density of ion channels. Dysfunctional primary cilia generate several diseases known as ciliopathies. However, the nature of ciliary signaling remains largely unknown. Herein, we determined by the patch-clamp technique, the electrical activity of cytoplasmic and axonemal MTs from LLC-PK1 renal epithelial cells. We observed electrical oscillations with fundamental frequencies at ~39 Hz and ~93 Hz in sheets of cytoplasmic MTs. We also studied isolated and in situ intact and Triton X-permeabilized primary cilia, observing electrical oscillations with peak frequencies at either 29-49 (non-permeabilized) or ~40-49 Hz (permeabilized) and ~93 Hz (both). The axonemal electrical oscillations changed with maneuvers that modify ciliary length, including addition of external Ca2+ and Li+. We also applied Continuous Wavelet Transform (CWT) and cross-correlation analyses in the Time-Frequency domain to assess the coherence between cytoplasmic and axonemal MT electrical oscillations. The evidence indicates that the primary cilium is an electrical antenna that produces MT-based electrical oscillations regulated by ciliary channels and receptors.