Journal of neurophysiology
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1. In Mg(2+)-free external solution, rat cortical neurons in cultured networks entered a stable firing mode, consisting of regular bursts of action potentials superimposed on long-lasting depolarizations. The average separation between bursts varied from culture to culture, but was usually between 5 and 20 s. ⋯ Occasionally, secondary rhythms were observed in which only a subset of cells participated. The times to peak and the decay times of calcium transients varied among synchronized cells. 6. The pharmacology of the burst-related calcium transients was investigated by bath application of a variety of compounds.(ABSTRACT TRUNCATED AT 400 WORDS)
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1. We studied the effect of electrical stimulation of the peribrachial region (PBR) in the brain stem on the visual response of single cells in the dorsal lateral geniculate nucleus (dLGN) to a light slit presented in a series of positions across the receptive field. The response was plotted against slit position, giving a spatial receptive field profile. 2. ⋯ We also examined the effect of ionophoretical application of acetylcholine (ACh) and bicuculline methchloride (BMC) on the spatial receptive field properties of dLGN cells. The effects of ACh were similar to those of PBR stimulation. Application of BMC, on the other hand, made the receptive field profile more similar to that of retinal ganglion cells.