Brain stimulation in the age of "light": Controlling and steering cortical cellular electrophysiology for future smart neuroprosthetics employing optogenetics

The brain is presumed to learn by altering the synaptic contacts between neurons. At the scale of neuronal microcircuits, its state is thus represented by a connectivity profile. Electrophysiological activity can alter this profile by inducing synaptic plasticity: changes in the strength and number of synapses. In turn, the wiring of a network influences the activity it can display. The interplay between activity and connectivity results in an equilibrium, susceptible to perturbations caused by new inputs into the network. Here, I will explore how the state of a network, cultured ex vivo on micro-electrode arrays, can be altered and controlled by external stimulation. This stimulation will be provided optogenetically: light-sensitive ion-channels are genetically targeted to specific neurons and consequently activated by shining light. The advantage is that the stimulation occurs spatio-temporally precise and on neuronally relevant time-scales. In addition, the stimulation will take into account, via real-time data analysis, the dynamic state of the network. This results in a so-called closed-loop: the stimulation influences the neuronal activity, which in turn affects the stimulation paradigm. A closed-loop approach is pivotal in the efficient interfacing with neuronal tissue. The results of this study will add to our knowledge of the fundamental properties of interfacing artificial electronic device to in vitro brain preparations, as in future brain prosthetic devices.

Keywords:NEURONAL MICROCIRCUITS, BRAIN RESEARCH

Disciplines:Neurosciences, Biological and physiological psychology, Cognitive science and intelligent systems, Developmental psychology and ageing