Maintenance of a central high frequency synapse in the absence of synaptic activity.

Activity has long been considered essential for circuit formation and maintenance. This view has recently been challenged by proper synaptogenesis and only mildly affected synapse maintenance in the absence of synaptic activity in forebrain neurons. Here, we investigated whether synaptic activity is necessary for the development and maintenance of the calyx of Held synapse.

Serine 937 phosphorylation enhances KCC2 activity and strengthens synaptic inhibition.

The potassium chloride cotransporter KCC2 is crucial for Cl extrusion from mature neurons and thus key to hyperpolarizing inhibition. Auditory brainstem circuits contain well-understood inhibitory projections and provide a potent model to study the regulation of synaptic inhibition. Two peculiarities of the auditory brainstem are (i) posttranslational activation of KCC2 during development and (ii) extremely negative reversal potentials in specific circuits.

Shared and organ-specific gene-expression programs during the development of the cochlea and the superior olivary complex.

The peripheral and central auditory subsystems together form a complex sensory network that allows an organism to hear. The genetic programs of the two subsystems must therefore be tightly coordinated during development. Yet, their interactions and common expression pathways have never been systematically explored.

Comparative expression analysis of the Atoh7 gene regulatory network in the mouse and chicken auditory hindbrain.

The mammalian and avian auditory brainstem likely arose by independent evolution. To compare the underlying molecular mechanisms, we focused on Atoh7, as its expression pattern in the mammalian hindbrain is restricted to bushy cells in the ventral cochlear nucleus. We thereby took advantage of an Atoh7 centered gene regulatory network (GRN) in the retina including upstream regulators, Hes1 and Pax6, and downstream targets, Ebf3 and Eya2.