Neurobeachin (Nbea) is a multidomain neuron-specific protein, which is highly expressed in the brain during development. Although the function of Nbea is still unknown, published evidence suggests a role in synaptic membrane protein trafficking. In the present study, we investigated its physiological function using a combined molecular biological and electrophysiological approach. Mutant mice lacking Nbea are incapable of breathing and die immediately after birth. Therefore, whole-cell patch-clamp experiments were carried out on the brainstem respiratory network of timed-pregnant E19 mice. Voltage-dependent Na⁺, K⁺, and Ca²⁺ currents were not affected in the KO mice, indicating no impairment of general neuronal excitability. However, the frequency and amplitude of spontaneous IPSC, but not EPSC, were severely reduced in Nbea-KO mice. Furthermore, the frequency of miniature IPSC, but not amplitude, was significantly decreased, and failure rate of evoked IPSC was markedly increased in KO mice. Our data suggests that Neurobeachin plays an essential role in GABA- and glycinergic synaptic transmission in the developing respiratory network of mouse.