The dynamics of a neuronal culture of dissociated cortical neurons of neonatal rats

Abstract

Classical receptive fields (cRF) increase in size from the retina to higher visual centers. The present work shows how temporal properties, in particular lateral spike velocity and spike input correlation, can affect cRF size and position without visual experience. We demonstrate how these properties are related to the spatial range of cortical synchronization if Hebbian learning dominates early development. For this, a largely reduced model of two successive levels of the visual cortex is developed (e.g., areas V1 and V2). It consists of retinotopic networks of spiking neurons with constant spike velocity in lateral connections. Feedforward connections between level 1 and 2 are additive and determine cRF size and shape, while lateral connections within level 1 are modulatory and affect the cortical range of synchronization. Input during development is mimicked by spike trains with spatially homogeneous properties and a confined temporal correlation width. During learning, the homogeneous lateral coupling shrinks to limited coupling structures defining synchronization and related association fields (AF). The size of level-1 synchronization fields determines the lateral coupling range of developing level-1-to-2 connections and, thus, the size of level-2 cRFs, even if the feedforward connections have distance-independent delays. AFs and cRFs increase with spike velocity in the lateral network and temporal correlation width of the input. Our results suggest that AF size of V1 and cRF size of V2 neurons are confined during learning by the temporal width of input correlations and the spike velocity in lateral connections without the need of visual experience. During learning from visual experience, a similar influence of AF size on the cRF size may be operative at successive levels of processing, including other parts of the visual system.

Homeostasis of neuronal avalanches during postnatal cortex development in vitro

“…In the cortex, this hallmark of spontaneous activity has been reported since the earliest culture success in vitro (Crain, 1966;Calvet, 1974) and naturally occurs in all isolated cortex preparations thus studied, e.g. in organotypic cultures (Plenz and Aertsen, 1996a;Plenz and Aertsen, 1996b;Gorba, Klostermann et al, 1999;Klostermann and Wahle, 1999;Baker, Corner et al, 2006), dissociated cultures (Maeda, Robinson et al, 1995;Gopal and Gross, 1996;Kamioka, Maeda et al, 1996;Canepari, Bove et al, 1997;Jimbo, Kawana et al, 2000;Segev, Shapira et al, 2001;van Pelt, Corner et al, 2004;Eytan and Marom, 2006), acute cortex slices (Sanchez-Vives and McCormick, 2000), and acutely isolated cortical slabs in vivo (Steriade, Nuñez et al, 1993;Timofeev, Grenier et al, 2000). Quantification of these Correspondence: Dr. Dietmar Plenz, Section on Critical Brain Dynamics, National Institute of Mental Health, Porter Neuroscience Research Center, Bldg.…”

Liquid state machines and cultured cortical networks: The separation property

“…These dynamics typically consist of episodes of increasing spontaneous asynchronous action potentials that culminate in a synchronous population burst of activity followed by a quiescent period. Simple inputs such as from a brief 200 us ±500 mV stimulation pulse delivered to a single electrode often evokes a burst of activity lasting over 100 ms and although the pattern of activity during the initial early phase of the network response is reliable (first 20 ms), the late phase (> 20 ms) is often more chaotic (Jimbo et al, 2000).…”

“…4). The early phase of the response (< 20 ms) likely represents activity from the direct activation of neurons nearby the stimulation electrode or neurons connected through short path lengths to neurons directly stimulated resulting in a reliable pattern of activity (Jimbo et al, 2000;?). In contrast, the response after this period (late phase) is often more variable and likely represents the reverberation of activity throughout the network.…”

“…The degradation of the HFS performance is due to the lack of evoked late activity. The decline of low frequency stimulation performance is likely due to the small tau used in creating the smoothed PSTHs and the accumulation of spike jitter as larger taus have shown better similarity between trials in other work (Jimbo et al, 2000). Recurrent activity from stimulations inducing bursting (0.33 Hz) reduces the ability to perform correct classification.…”

Editorial: models of invertebrate neurons in culture

“…neurons and glia), organize to form a complex functional unit-the neural network, and how these building blocks connect and interact to form further elaborate neuronal structures are extremely tractable in two-dimensional in vitro preparations of primary neuronal cultures (e.g. Bulloch and Syed 1992;Jimbo et al 2000;Shefi et al 2002;Darya et al 2009; and see Beadle 2006 for review of insect neural cultures). The in vitro system is simple (relative to any in vivo network), and allows control over as many of its variables as possible.…”