Synaptic Refinement of an Inhibitory Topographic Map in the Auditory Brainstem Requires Functional CaV1.3 Calcium Channels
| Autor: | Nadine Braun, Katrin Janz, Stefan Löhrke, Eckhard Friauf, Jan J. Hirtz, Christian Hannes, Britta Müller, Désirée Griesemer |
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| Rok vydání: | 2012 |
| Předmět: |
Male
Calcium Channels L-Type Stimulation Inhibitory postsynaptic potential Synaptic Transmission Cav1.3 Mice chemistry.chemical_compound Organ Culture Techniques Evoked Potentials Auditory Brain Stem Biological neural network Animals Neurotransmitter Glycine receptor Mice Knockout Brain Mapping biology Voltage-dependent calcium channel General Neuroscience Neural Inhibition Articles Mice Inbred C57BL Phenotype Inhibitory Postsynaptic Potentials chemistry Synapses biology.protein Female Brainstem Neuroscience Brain Stem |
| Zdroj: | The Journal of Neuroscience. 32:14602-14616 |
| ISSN: | 1529-2401 0270-6474 |
| DOI: | 10.1523/jneurosci.0765-12.2012 |
| Popis: | Synaptic refinement via the elimination of inappropriate synapses and strengthening of appropriate ones is crucially important for the establishment of specific, topographic neural circuits. The mechanisms driving these processes are poorly understood, particularly concerning inhibitory projections. Here, we address the refinement of an inhibitory topographic projection in the auditory brainstem in functional and anatomical mapping studies involving patch-clamp recordings in combination with minimal and maximal stimulation, caged glutamate photolysis, and single axon tracing. We demonstrate a crucial dependency of the refinement on CaV1.3 calcium channels:CaV1.3−/−mice displayed virtually no elimination of projections up to hearing onset. Furthermore, strengthening was strongly impaired, in line with a reduced number of axonal boutons. The mediolateral topography was less precise and the shift from a mixed GABA/glycinergic to a purely glycinergic transmission before hearing onset did not occur. Together, our findings provide evidence for a CaV1.3-dependent mechanism through which both inhibitory circuit formation and determination of the neurotransmitter phenotype are achieved. |
| Databáze: | OpenAIRE |
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