Layer-specific inhibitory microcircuits of layer 6 interneurons in rat prefrontal cortex

bioRxiv (Cold Spring Harbor Laboratory)

Abstract

Abstract GABAergic interneurons in different cortical areas play important roles in diverse higher order cognitive functions. The heterogeneity of interneurons is well characterized in different sensory cortices, in particular in primary somatosensory and visual cortex. However, the structural and functional properties of the medial prefrontal cortex (mPFC) interneurons have received less attention. In this study, a cluster analysis based on axonal projection patterns revealed four distinct clusters of L6 interneurons in rat mPFC: Cluster 1 interneurons showed axonal projections similar to Martinotti-like cells extending to layer 1, cluster 2 displayed translaminar projections mostly to layer 5, cluster 3 interneuron axons were confined to the layer 6, whereas those of cluster 4 interneurons extend also into the white matter. Correlations were found between neuron location and axonal distribution in all clusters. Moreover, all cluster 1 L6 interneurons showed a monotonically adapting firing pattern with an initial high-frequency burst. All cluster 2 interneurons were fast-spiking, while neurons in cluster 3 and 4 showed heterogeneous firing patterns. Our data suggest that L6 interneurons that have distinct morphological and physiological characteristics are likely to innervate different targets in mPFC thus play differential roles in the L6 microcircuitry and in mPFC-associated functions.

Authors 4

1. Chao Ding

   Forschungszentrum Jülich

   Affiliation as printed

   Research Centre Jülich, Institute of Neuroscience and Medicine, INM-10 Medicine, 52425 Jülich, Germany

   Research Centre Jülich, Institute of Neuroscience and Medicine, INM-0 Medicine, 52425 Jülich, Germany

2. Vishalini Emmenegger

   ETH Zurich · Forschungszentrum Jülich

   Affiliation as printed

   Dept of Biosystems Engineering, ETH Zürich, Basel, Switzerland

   Research Centre Jülich, Institute of Neuroscience and Medicine, INM-10 Medicine, 52425 Jülich, Germany

   Research Centre Jülich, Institute of Neuroscience and Medicine, INM-0 Medicine, 52425 Jülich, Germany

3. Kim Schaffrath Aachen Department of Ophthalmology Department of Ophthalmology

   RWTH Aachen University · Universitätsklinikum Aachen · Forschungszentrum Jülich

   Affiliation as printed

   Dept of Ophthalmology, RWTH Aachen University Hospital, Medical School, 52074 Aachen, Germany

   Research Centre Jülich, Institute of Neuroscience and Medicine, INM-10 Medicine, 52425 Jülich, Germany

   Dept of Ophthalmology, RWTH Aachen University Hospital, Medical School, 2074 Aachen, Germany

   Research Centre Jülich, Institute of Neuroscience and Medicine, INM-0 Medicine, 52425 Jülich, Germany

4. Dirk Feldmeyer corresponding Aachen Department of Psychiatry, Psychotherapy and Psychosomatics Medical School

   RWTH Aachen University · Universitätsklinikum Aachen · Forschungszentrum Jülich · Jülich Aachen Research Alliance

   Affiliation as printed

   Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University Hospital, 52074 Aachen, Germany

   JARA-Translational Brain Medicine

   Research Centre Jülich, Institute of Neuroscience and Medicine, INM-10 Medicine, 52425 Jülich, Germany

   Department of Psychiatry, Psychotherapy and Psychosomatics, Medical School, RWTH Aachen University Hospital, 5074 Aachen, Germany

   Research Centre Jülich, Institute of Neuroscience and Medicine, INM-0 Medicine, 52425 Jülich, Germany