neuron attachment, such as laminin, or drug eluting substances. applications in vitro the nature of dissociated neuronal networks does not seem to change or diminish the character of its pharmacological response when compared to in vivo models, suggesting that meas can be used to study pharmacological effects on dissociated neuronal cultures in a more simple, controlled environment. a number of pharmacological studies using meas on dissociated neuronal networks, e.g. studies with ethanol. interlaboratory validation has been conducted using meas. in addition, a substantial body of work on various biophysical aspects of network function was carried out by reducing phenomena usually studied at the behavioral level to the dissociated cortical network level. for example, the capacity of such networks to extract spatial and temporal features of various input signals, dynamics of synchronization, sensitivity to neuromodulation and kinetics of learning using closed loop regimes. finally, combining mea technology with confocal microscopy allows for studying relationships between network activity and synaptic remodeling. meas have been used to interface neuronal networks with non-biological systems as a controller. for example, a neural-computer interface can be created using meas. dissociated rat cortical neurons were integrated into a closed stimulus-response feedback loop to control an animat in a virtual environment. a closed-loop stimulus-response system has also been constructed using an mea by potter, mandhavan, and demarse, and by mark hammond, kevin warwick, and ben whalley in the university of reading. about 300,000 dissociated rat neurons were plated on an mea, which was connected to motors and ultrasound sensors on a robot, and was conditioned to avoid obstacles when sensed. along these lines, shimon marom and colleagues in the technion hooked dissociated neuronal networks growing on meas to a lego mindstorms robot; the visual field of the robot was classified by the network, and commands were delivered to the robot wheels such that it completely avoids bumping into obstacles. this "braitenberg vehicle" was used to demonstrate the indeterminacy of reverse neuro-engineering showing that even in a simple setup with practically unlimited access to every piece of relevant information, it was impossible to deduce with certainty the specific neural coding scheme that was used to drive the robots behavior. meas have been used to observe network firing in hippocampal slices. in vivo there are several implantable interfaces that are currently available for consumer use including deep brain stimulators, cochlear implants, and cardiac pacemakers. deep brain stimulation (dbs) has been effective at treating movement disorders such as parkinson's disease, and cochlear implants have helped many to improve their hearing by assisting stimulation of the auditory nerve. because of their remarkable potential, meas are a prominent area of neuroscience research. research suggests that meas may provide insight into processes such as memory formation and perception and may also hold therapeutic value for conditions such as epilepsy, depression, and obsessive-compulsive disorder . clinical trials using interface devices for restoring motor control after spinal cord injury or as treatment for als have been initiated in a project entitled braingate (see video demo: braingate). meas provide the high resolution necessary to record time varying signals, giving them the ability to be used to both control and obtain feedback from prosthetic devices, as was shown by kevin warwick, mark gasson and peter kyberd. research suggests that mea use may be able to assist in the restoration of vision by stimulating the optic pathway. mea user meetings a biannual scientific user meeting is held in reutlingen, organized by the natural and medical sciences institute (nmi) at the university of tübingen. the meetings offer a comprehensive overview of all aspects related to new developments and current applications of microelectrode arrays in basic and applied neuroscience as well as in industrial drug discovery, safety pharmacology and neurotechnology. the biannual conference has developed into an international venue for scientists developing and using meas from both industry and academia, and is recognized as an information-packed scientific forum of high quality. the meeting contributions are available as open access proceeding books. use in art in addition to being used for scientific purposes, meas have been used in contemporary art to investigate philosophical questions about the relationship between technology and biology. traditionally within western thought, biology and technology have been separated into two distinct categories: bios and technê. in 2002, meart: the semi-living artist was created as a collaborative art and science project between symbiotica at the university of western australia in perth, and the potter lab at the georgia institute of technology in atlanta, to question the relationship between biology and technology. meart consisted of rat cortical neurons grown in vitro on an mea in atlanta, a pneumatic robot arm capable of drawing with pens on paper in perth, and software to govern communications between the two. signals from the neurons were relayed in a closed-loop between perth and atlanta as the mea stimulated the pneumatic arm. meart was first exhibited to the public in the exhibition biofeel at the perth institute of contemporary arts in 2002.