Functional maps of neocortical local circuitry
- The Department of Pharmacology, The School of Pharmacy, University of London, London, UK
This review aims to summarize data obtained with different techniques to provide a functional map of the local circuit connections made by neocortical neurones, a reference for those interested in cortical circuitry and the numerical information required by those wishing to model the circuit. A brief description of the main techniques used to study circuitry is followed by outline descriptions of the major classes of neocortical excitatory and inhibitory neurones and the connections that each layer makes with other cortical and subcortical regions. Maps summarizing the projection patterns of each class of neurone within the local circuit and tables of the properties of these local circuit connections are provided.
This review relies primarily on anatomical studies that have identified the classes of neurones and their local and long distance connections and on paired intracellular and whole-cell recordings which have documented the properties of the connections between them. A large number of different types of synaptic connections have been described, but for some there are only a few published examples and for others the details that can only be obtained with paired recordings and dye-filling are lacking. A further complication is provided by the range of species, technical approaches and age groups used in these studies. Wherever possible the range of available data are summarised and compared. To fill some of the more obvious gaps for the less well-documented cases, data obtained with other methods are also summarized.
Keywords:
cortex, pyramidal cell, interneuron(e), synapse, EPSP/C (excitatory postsynaptic potential/current), IPSP/C (inhibitory postsynaptic potential/current)
Citation:
Alex M. Thomson and Christophe Lamy (2007). Functional maps of neocortical local circuitry. Front. Neurosci. 1:1. 19-42. doi: 10.3389.neuro.01/1.1.002.2007
Received: 15 August 2007; Paper pending published: 01 September 2007;
Accepted: 01 September 2007;
Published online: 15 October 2007.
Reviewed by:
Gilad Silberberg, Nobel Institute for Neurophysiology, Karolinska Institute, Sweden; Ora Ohana, Department of Biology-Chemistry-Pharmacy, Freie Universität Berlin, Germany
Copyright:
© 2007 Thomson and Lamy. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence:
Alex M. Thomson. The Department of Pharmacology, The School of Pharmacy, University of London, 29-39 Brunswick Square, London WC1N 1AX, UK. e-mail: alex.thomson@pharmacy.ac.uk