Synaptic Refinement of an Inhibitory Topographic Map in the Auditory Brainstem Requires Functional CaV1.3 Calcium Channels

• DOI: 10.1523/jneurosci.0765-12.2012
• Publication Date: 2012-10-18T05:22:33Z
• Authors: Jan J. Hirtz; Nadine Braun; Désirée Griesemer; Christian Hannes; Katrin Janz; Stefan Löhrke; Britta Müller; Eckhard Friauf
• Keywords: Auditory brainstem response

Synaptic refinement via the elimination of inappropriate synapses and strengthening appropriate ones is crucially important for establishment specific, topographic neural circuits. The mechanisms driving these processes are poorly understood, particularly concerning inhibitory projections. Here, we address an projection in auditory brainstem functional anatomical mapping studies involving patch-clamp recordings combination with minimal maximal stimulation, caged glutamate photolysis, single axon tracing. We demonstrate a crucial dependency on Ca V 1.3 calcium channels: −/− mice displayed virtually no projections up to hearing onset. Furthermore, was strongly impaired, line reduced number axonal boutons. mediolateral topography less precise shift from mixed GABA/glycinergic purely glycinergic transmission before onset did not occur. Together, our findings provide evidence 1.3-dependent mechanism through which both circuit formation determination neurotransmitter phenotype achieved.