Systems biology

Smallness is a great advantage when one wants to model a system, and invertebrate nervous systems have long served as subjects for modellers. Generally, these have been relatively local models involving a single structure in the nervous system. But with the advent of physiological techniques to sample more widely and with perturbations that can be directed at combinations of brain regions, modelling on a more global scale becomes accessible. The preparation may lack backbone, but its potential for systems neurobiology does not. Finally, there is yet another virtue to probing the breadth and depth of complex brain function in Buchsbaum's subkingdom, quite separate from whatever similarities they may share with us 'higher' (sic) creatures. That virtue was recently summarized by T.H. Bullock [3] who, in addition to being one of the pioneers of invertebrate neurobiology, has also been one of its principal missionaries and practitioners: " We are seriously lacking in knowledge of what the actual differences are between less complex and more complex brains, particularly in their physiology. Crude, low magnification histology tells us there are marked differences between taxa of several grades of complexity, but in spite of off and on claims of more speech cortex and prefrontal lobes in humans, we have no neural basis for the vast differences in behavioral complexity between humans and other species. " We have our work cut out for us. Zeitgeist redux? A Medline search for 'systems biology' reveals an interesting trend: the number of papers that mention this phrase has gone from less than 10 in the year 2000, to over 140 in 2003. But the application of systems theory to biology is not new: initial attempts date back to the 1940s. The renaissance was sparked by completion of the human genome sequence, and fueled by a proliferation of data from the genomics revolution. The availability of powerful computational tools and broad-band internet connections has also greatly facilitated the analysis and distribution of vast datasets, on which systems biology is largely based. What exactly is systems biology? It all depends on whom you ask, but there are at least two general camps of people doing, and talking about systems biology. What they have in common is a focus on understanding the components and dynamic behaviors of biological systems. The first group can be thought of as the panomicists. These researchers combine different high-throughput data, such as transcriptomes and proteomes, to …