Information transmission rate changes of retinal ganglion cells during contrast adaptation.

During adaptation to high-contrast stimulation, retinal ganglion cell's responsiveness change is characterized by decreased firing rate and declined sensitivity. In order to examine the modification of information transmission properties of the ganglion cell during this adaptation process, neural activities were recorded extracellularly from the chicken retina using a multi-electrode recording system, and the information transmission rate of the retinal ganglion cells was estimated. The results show that the response entropy and noise entropy of the ganglion cells both decreased during the adaptation process, which resulted in a modest decline of information transmission rate of ganglion cells after several seconds' adaptation. However, due to the decrease of the neuron's firing rate during the adaptation, it is revealed that the information carried by each spike was increased as compared to pre-adaptation, suggesting that retinal ganglion cells' information processing strategies during contrast adaptation may reflect economical principle by promoting each spike more informative. These results also suggest that contrast adaptation and sensitivity rescaling of the visual neurons provide an efficient manner in information transmission and save the system's metabolic cost in the meantime.