Cellular neuroanatomy of rat presubiculum

Abstract

The presubiculum, at the transition from the hippocampus to the cortex, is a key area for spatial information coding but the anatomical and physiological basis of presubicular function remains unclear. Here we correlated the structural and physiological properties of single neurons of the presubiculum in vitro. Unsupervised cluster analysis based on dendritic length and form, soma location, firing pattern and action potential properties allowed us to classify principal neurons into three major cell types. Cluster 1 consisted of a population of small regular spiking principal cells in layers II/III. Cluster 2 contained intrinsically burst firing pyramidal cells of layer IV, with a resting potential close to threshold. Cluster 3 included regular spiking cells of layers V and VI, and could be divided into subgroups 3.1 and 3.2. Cells of cluster 3.1 included pyramidal, multiform and inverted pyramidal cells. Cells of cluster 3.2 contained high-resistance pyramidal neurons that fired readily in response to somatic current injection. These data show that presubicular principal cells generally conform to neurons of the periarchicortex. However, the presence of intrinsic bursting cells in layer IV distinguishes the presubicular cortex from the neighbouring entorhinal cortex. The firing frequency adaptation was very low for principal cells of clusters 1 and 3, a property that should assist the generation of maintained head direction signals in vivo.

Non-linear developmental trajectory of electrical phenotype in rat substantia nigra pars compacta dopaminergic neurons

“…So far, multivariate analyses, and in particular clustering analysis, have been mainly used in neurophysiology to classify and distinguish mature neuronal populations (Ascoli et al, 2008; Karagiannis et al, 2009; McGarry et al, 2010; Laramee et al, 2013; Simonnet et al, 2013). For instance, research dedicated to the classification of cortical interneuron subpopulations (for review see Ascoli et al, 2008; Defelipe et al, 2013) has led to the creation of an international consortium (the Petilla Interneuron Nomenclature Group).…”

Hippocampal Formation

“…Intracellular filling of electrophysiologically defined neurons revealed stellate as well as pyramidal cells in both superficial and deep layers of the PrS (Funahashi and Stewart, 1997a;Simonnet et al, 2013). For further details on the cytoarchitectonic organization of the PrS as well as the description of several characteristics of the PrS that help to differentiate it from the PaS the reader is referred to studies by Haug (1976), Van Groen and Wyss (1990a) Insausti et al (1997) and Kjønigsen et al (2011).…”

“…Both layers contain small pyramidal cells with spiny dendrites that are restricted to the superficial layers. Local axonal collaterals of these cells reach into the deep layers of PrS (Funahashi and Stewart, 1997a;Simonnet et al, 2013).…”

“…Although the lamina dissecans is dubbed cell-free layer, it contains large pyramidal cells, with apical dendrites extending mainly into layer I-IV and some dendrites entering deep layers (Simonnet et al, 2013).…”

“…The dendrites of the layer V pyramidal cells, which have an important role in head-direction information processing (Taube et al, 1990), spread into the superficial layers Stewart, 1997a, 1997b;Honda et al, 2011;Simonnet et al, 2013). The axons of the cells in the deep layers project to all PrS layers (Honda et al, 2008(Honda et al, , 2011 and into the white matter (Simonnet et al, 2013).…”