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Barbour, B.

Publications and source records attributed to Barbour, B..

2 recordsLinked to original sources

Automatic post-processing and merging of multiple spike-sorting analyses with Lussac

The rise in site counts of multi-electrodes used in extracellular recordings in the brain has driven the development of increasingly automated spike-sorting packages. However, post-processing is still largely manual and it remains difficult to determine the optimal package and parameters for a given recording. It has recently been shown that different packages produce quite disparate outputs, suggesting that a combination of analyses might be beneficial. Here, we describe the formalization of existing and new metrics of unit quality and comparison, then build upon these to automate the creation of a consensus output from multiple analyses. We validated our package against synthetic and real ground truths. Compared to individual analyses, our package increased the yield and quality of correct units (doubling the yield of Purkinje cells in our recordings) and, crucially, eliminated numerous incorrect units that were impossible to identify in a single analysis. These improvements also increase analytical objectivity and reduce manual effort.

neuroscience↗

Large, stable spikes exhibit differential broadening in excitatory and inhibitory neocortical boutons

Presynaptic action potential spikes control neurotransmitter release and thus interneuronal communication. However, the properties and the dynamics of presynaptic spikes in the neocortex remain enigmatic because boutons in the neocortex are small and direct patch-clamp recordings have not been performed. Here we report direct recordings from boutons of neocortical pyramidal neurons and interneurons. Our data reveal rapid and large presynaptic action potentials in layer 5 neurons and fast-spiking interneurons reliably propagating into axon collaterals. For in-depth analyses we validate boutons of mature cultured neurons as models for excitatory neocortical boutons, demonstrating that the presynaptic spike amplitude was unaffected by potassium channels, homeostatic long-term plasticity, and high-frequency firing. In contrast to the stable amplitude, presynaptic spikes profoundly broadened for example during high-frequency firing in layer 5 pyramidal neurons but not in fast-spiking interneurons. Thus, our data demonstrate large presynaptic spikes and fundamental differences between excitatory and inhibitory boutons in the neocortex.

neuroscience↗