Multielectrode analysis of coordinated, multisite, rhythmic bursting in cultured CNS monolayer networks

Abstract

Laser-deinsulated, printed-circuit electrodes integrated into the floor of culture chambers have been used to monitor the spontaneous activity of mouse spinal monolayer cell cultures. This technique has allowed a multisite analysis of activity over long periods of time in closed chambers. In 63 cultures investigated 3-5 weeks after seeding, 89% included single- or multiunit bursting. Based on a subset of 40 cultures in which all electrodes were sequentially scanned, bursting was found on 41% of the active electrodes (approximately 38% of all units monitored). A total of 35% of the electrodes monitoring spontaneous bursting activity revealed rhythmic sequences that were usually coupled among multiple electrodes. Although most of this coupling was in-phase, three out of 40 cultures exhibited antiphasic bursting. In all cases where coupling was observed, each electrode monitored different burst compositions, demonstrating that the activity was generated by different units. Some rhythmic patterns persisted for over 12 hr and were observed in 400 mm2 monolayer cultures, as well as in much smaller 3 mm2 adhesion islands. The addition of 10 mM MgCl2 consistently blocked both random and patterned (i.e., bursting) spontaneous activity at all recording sites. Strychnine (10(-6) M) typically increased firing frequencies and either disrupted pretest bursting or generated rhythmic activity from random phasic patterns. In certain cases, strychnine also blocked activity on specific electrodes, indicating that glycine is not the only inhibitory transmitter involved. The spontaneous appearance of rhythmic activity in low-density, monolayer cell cultures established from dissociated and randomly seeded spinal tissue can be explained by one or a combination of two hypotheses: an inherent specificity of some interconnections in developing mammalian cultures and the generation of organized activity by random circuits at certain stages of complexity.

Biological application of microelectrode arrays in drug discovery and basic research

“…As the MEA technology can be applied to any electrogenic tissue, that is, central and peripheral neurons, heart cells, and muscle cells [12,14,18,24,25,26,27,28,29,30,31], the MEA biosensor is an ideal in vitro system to monitor both acute and chronic effects of drugs and toxins and to perform functional studies under physiological or induced pathophysiological conditions that mimic in vivo damage. By recording the electrical response of various locations on a tissue, a spatial map of drug effects at different sites can be generated which provides important clues about a drug's specificity.…”

Controlling Bursting in Cortical Cultures with Closed-Loop Multi-Electrode Stimulation

“…Such cultures retain many morphological, pharmacological, and electrical properties of cortical networks in vivo (Dichter, 1978) and allow much more detailed observation and manipulation than intact brains, at the molecular, cellular, and network levels (Droge et al, 1986;Emery et al, 1991;Curtis et al, 1992;Wilkinson, 1993;Bove et al, 1994Bove et al, , 1997Rhoades et al, 1996;Canepari et al, 1997;Gross et al, 1997;Liu et al, 1997;Harsch et al, 1998;Honma et al, 1998;Jimbo et al, 1998Jimbo et al, , 1999Turrigiano, 1999;Harsch and Robinson, 2000;Zhu et al, 2000;Keefer et al, 2001;Streit et al, 2001;Shahaf and Marom, 2001;Corner et al, 2002).…”

Spontaneous coordinated activity in cultured networks: Analysis of multiple ignition sites, primary circuits, and burst phase delay distributions

“…In this manuscript we perform an extensive quantitative analysis of patterns of network burst initiation in cortical neural networks in vitro. These spontaneous collective high frequency action potential discharges are major features of such systems [2, 8,10,18,19,23,24,[36][37][38] and can influence learning and information processing by changing synaptic properties [1,5]. Previous theoretical and experimental research showed that multiple ignition sites, sometimes termed initiation loci [24], privileged neurons [11], and even initiation zones [12], create network bursts by recruiting constituent neurons.…”