Calcium ions (Ca2+) play important roles as secondary messengers in the body. The intracellular Ca2+ concentration is increased via 2 mechanisms: (1) is an influx of external Ca2+ and (2) Ca2+ release from the endoplasmic reticulum. Ca2+ influx across the plasma membrane involves 3 main types of channels: voltage-dependent calcium channels (VDCCs), ligand-gated calcium channels, and transient receptor potential (TRP) channels. VDCCs are activated by depolarization of membrane potential. VDDC-mediated Ca2+ signaling is essential for neurotransmitter release, synaptic plasticity, and gene transcription. The TRP family comprises at least 28 cation channels, most of which are permeable to Ca2+. TRP channels function as cellular sensors and are activated by various chemical and physical stimuli. In the nervous system, Ca2+ signaling via TRP channels is important for neuronal growth, development, survival, and cell death. In this review, we discuss how Ca2+ signaling via VDCCs and TRP channels mediates various neuronal processes.