%0 Journal Article %T Detection of M-Sequences from Spike Sequence in Neuronal Networks %A Yoshi Nishitani %A Chie Hosokawa %A Yuko Mizuno-Matsumoto %A Tomomitsu Miyoshi %A Hajime Sawai %A Shinichi Tamura %J Computational Intelligence and Neuroscience %D 2012 %I Hindawi Publishing Corporation %R 10.1155/2012/862579 %X In circuit theory, it is well known that a linear feedback shift register (LFSR) circuit generates pseudorandom bit sequences (PRBS), including an M-sequence with the maximum period of length. In this study, we tried to detect M-sequences known as a pseudorandom sequence generated by the LFSR circuit from time series patterns of stimulated action potentials. Stimulated action potentials were recorded from dissociated cultures of hippocampal neurons grown on a multielectrode array. We could find several M-sequences from a 3-stage LFSR circuit (M3). These results show the possibility of assembling LFSR circuits or its equivalent ones in a neuronal network. However, since the M3 pattern was composed of only four spike intervals, the possibility of an accidental detection was not zero. Then, we detected M-sequences from random spike sequences which were not generated from an LFSR circuit and compare the result with the number of M-sequences from the originally observed raster data. As a result, a significant difference was confirmed: a greater number of ˇ°0¨C1ˇ± reversed the 3-stage M-sequences occurred than would have accidentally be detected. This result suggests that some LFSR equivalent circuits are assembled in neuronal networks. 1. Introduction The brain is recognized as a very large-scale network system in which the basic element is a neuron [1¨C4]. In recent studies of the memory mechanism in the brain, investigating a formation of information communication is more essential than specifying the region of memory in the brain [4]. The basic study of communication method in the brain is to clarify the coding mechanism of information. Therefore varieties of coding for neuronal information, for example, rate code, were proposed in previous studies [5¨C15]. The first theory of information architecture is cell-assembly theory proposed by Hebb in 1949 [16, 17]. Abeles postulated that ˇ°synfire chainsˇ± of spike with relatively fixed intervals could travel through the brain representing information and various behavioral states [18¨C21]. Rolston and others have observed a robust set of spontaneously repeating spatiotemporal patterns of neuronal activity using a template matching algorithm [22]. Then, the question arises as to how the data communication is controlled and what and how the form of controlled data communication is constructed. This question is essential to investigate the mechanism, how information is communicated in more detail. To resolve this question, decoding sequence pattern in one block of spike activity (analyzing time series patterns of %U http://www.hindawi.com/journals/cin/2012/862579/