Real-Time Emulation of Neural Images in the Outer Retinal Circuit

Abstract

Abstract:We describe a novel real-time system that emulates the architecture and functionality of the vertebrate retina. This system reconstructs the neural images formed by the retinal neurons in real time by using a combination of analog and digital systems consisting of a neuromorphic silicon retina chip, a field-programmable gate array, and a digital computer. While the silicon retina carries out the spatial filtering of input images instantaneously, using the embedded resistive networks that emulate the receptive field structure of the outer retinal neurons, the digital computer carries out the temporal filtering of the spatially filtered images to emulate the dynamic properties of the outer retinal circuits. The emulations of the neural image, including 128 × 128 bipolar cells, are carried out at a frame rate of 62.5 Hz. The emulation of the response to the Hermann grid and a spot of light and an annulus of light has demonstrated that the system responds as expected by previous physiological and psychophysical observations. Furthermore, the emulated dynamics of neural images in response to natural scenes revealed the complex nature of retinal neuron activity. We have concluded that the system reflects the spatiotemporal responses of bipolar cells in the vertebrate retina. The proposed emulation system is expected to aid in understanding the visual computation in the retina and the brain.

The Role of Transient Receptor Potential Vanilloid 1 in Common Diseases of the Digestive Tract and the Cardiovascular and Respiratory System

“…Increased expression of TRPV1 in sensory nerves has been demonstrated in patients with chronic cough (Mitchell et al, 2005). Moreover, patients with chronic cough have an increase in sensitivity to capsaicin (Pecova et al, 2008). An increased level of bradykinin is shown in the airways of asthmatic patients, which causes cough after activation of TRPV1 (Grace et al, 2012).…”

Real-time emulation of dynamic features of sustained and transient channels in vertebrate retina

“…Figure 2 shows the temporal filter used to emulate the sustained properties of bipolar cells (solid circles). The details of convolution operation have been described elsewhere [19]. …”

Real-time emulation of parallel channel responses in the vertebrate retina and the primary visual cortex

“…). A part of detailed operation of the retina emulator is written in [2]. The cortex emulator receives spike signals from two retina emulators and emulates responses of cortex neurons including the simple and complex cells.…”