Layer 6A Pyramidal Cell Subtypes Form Synaptic Microcircuits with Distinct Functional and Structural Properties
Open Access
- 9 October 2021
- journal article
- research article
- Published by Oxford University Press (OUP) in Cerebral Cortex
- Vol. 32 (10), 2095-2111
- https://doi.org/10.1093/cercor/bhab340
Abstract
Neocortical layer 6 plays a crucial role in sensorimotor co-ordination and integration through functionally segregated circuits linking intracortical and subcortical areas. We performed whole-cell recordings combined with morphological reconstructions to identify morpho-electric types of layer 6A pyramidal cells (PCs) in rat barrel cortex. Cortico-thalamic (CT), cortico-cortical (CC), and cortico-claustral (CCla) PCs were classified based on their distinct morphologies and have been shown to exhibit different electrophysiological properties. We demonstrate that these three types of layer 6A PCs innervate neighboring excitatory neurons with distinct synaptic properties: CT PCs establish weak facilitating synapses onto other L6A PCs; CC PCs form synapses of moderate efficacy, while synapses made by putative CCla PCs display the highest release probability and a marked short-term depression. For excitatory-inhibitory synaptic connections in layer 6, both the presynaptic PC type and the postsynaptic interneuron type govern the dynamic properties of the respective synaptic connections. We have identified a functional division of local layer 6A excitatory microcircuits which may be responsible for the differential temporal engagement of layer 6 feed-forward and feedback networks. Our results provide a basis for further investigations on the long-range CC, CT, and CCla pathways.Keywords
Funding Information
- DFG Research Group—BaCoFun (Fe471/4-2)
- European Union’s Horizon 2020 research innovation programme (785907)
- China Scholarship Council
This publication has 110 references indexed in Scilit:
- Expression profiling of mouse subplate reveals a dynamic gene network and disease association with autism and schizophreniaProceedings of the National Academy of Sciences of the United States of America, 2013
- Morphology and Physiology of Excitatory Neurons in Layer 6b of the Somatosensory Rat Barrel CortexCerebral Cortex, 2012
- Transformations in oscillatory activity and evoked responses in primary somatosensory cortex in middle age: A combined computational neural modeling and MEG studyNeuroImage, 2010
- Cell Type–Specific Thalamic Innervation in a Column of Rat Vibrissal CortexCerebral Cortex, 2010
- Evolution of the neocortex: a perspective from developmental biologyNature Reviews Neuroscience, 2009
- Developmental alterations in the functional properties of excitatory neocortical synapsesJournal Of Physiology-London, 2009
- Petilla terminology: nomenclature of features of GABAergic interneurons of the cerebral cortexNature Reviews Neuroscience, 2008
- Maturation of Intrinsic and Synaptic Properties of Layer 2/3 Pyramidal Neurons in Mouse Auditory CortexJournal of Neurophysiology, 2008
- Robust but delayed thalamocortical activation of dendritic-targeting inhibitory interneuronsProceedings of the National Academy of Sciences of the United States of America, 2008
- Efficacy and connectivity of intracolumnar pairs of layer 2/3 pyramidal cells in the barrel cortex of juvenile ratsJournal Of Physiology-London, 2006