Prof. Felix Felmy, University of Veterinary Medicine Hanover

In mammals, the neuronal brainstem circuits involved in processing auditory information are supposed to be highly conserved. These archaic circuits are found in all mammals, as exemplified by the general existence of the medial nucleus of the trapezoid body (MNTB). This nucleus relays auditory information reliably and with temporally highly precision to feed forward inhibitory information to various auditory brainstem centers including binaural coincidence detectors. The cellular specializations that underlie this faithful synaptic transmission are a giant presynaptic nerve-terminal targeting the soma and postsynaptically large sodium currents and low voltage activated potassium currents. Since mammals come in different sizes and live in different niches it remains unclear whether these archaic circuits have undergone specific species-dependent adaptations that can be explained by phylogeny or allometric scaling. To gain insight into this question, we using whole-cell patch-clamp recordings and immunofluorescence labeling to analyze the different cellular contributions to the generally rapid input-output functions of MNTB neurons in various mammals.