I have shared what has been learned about the mechanism of synaptic transmission in my books and blog posts over the last four years. I will discuss an exciting article by Richard A. Normann and his coworkers entitled “Toward the Development of a Cortically Based Visual Neuroprosthesis” that was published in J Neurol Eng, June, 2009. The authors were motivated by the success of cochlear implants in restoring auditory capacity. The goal of their research is the creation of a visual neuroprosthesis designed to interface with the occipital cortex to restore a “useful sense of vision” in blind patients. I quote from their article, “Because retinal degeneration does not appear to spread to the neurons of the higher visual centers, a cortical approach for a visual prosthesis could provide an interventional site for virtually all forms of retinal blindness, trauma to the retinal and optic nerve, and blindness necessitated by precortical surgical procedures.”
In synaptic transmission we have seen that spike trains of action potentials carry linguistically encoded patterns of specified information instantiated within wave forms that, by quantum tunneling, are transmitted through synapses to stimulate postsynaptic action potentials that transmit the neural codes within spike trains to end points to bring about specific actions. There are both material and immaterial components to this elaborate process of dualist interaction. It is a created, designed process that provides for personal interaction between human cognitive minds and with the Mind of God through His indwelling Holy Spirit.
Let us examine the process being developed by the authors of this article and seek analogies with transmission within human synaptic networks. I quote:
“A cortical visual prosthesis, like other proposed approaches to sight restoration, would consist of a video camera [analogous with the retina], concealed in a pair of eyeglasses that generates a video data stream [spike trains of action potentials encoded with linguistic specified information] which captures the visual scene in front of the subject. This video data stream is then transformed and processed by a bioinspired retinal-like encoder [analogous to the generation of meaning and purpose within linguistic neural codes of spike trains]. This encoder would remap visual space onto cortical space and adjust the stimulus levels delivered to the implanted cortical electrodes. The digital data stream would then be transmitted wirelessly [via wave forms] to a number of electrode arrays implanted in the subject’s visual cortex [analogous to cortical modules whereby incoming wave forms transmitting neurally encoded, specified information within spike trains of action potentials are matched with wave forms within specific cortical modules to generate synchronous wave forms that are transmitted through synaptic networks with direction and purpose.]” The authors continue, “The processed digital data stream would produce a two-dimensional spatio-temporal pattern of electrical currents [analogous with encoded spike trains of action potentials] that would be injected into the cortical tissues [synaptic network endpoints within the cortex] via the implanted electrode arrays, and a two-dimension visual percept would be created in the subject [analogous to the interpretation by the cognitive mind of the meaning and purpose within the transmitted linguistic neural codes].”
I highly recommend this article to interested readers. I conclude with the following quotation from their article: “The goal of developing such a bioinspired retinal encoder is not to simply record a high-resolution image, but to transmit visual information in a meaningful way to the appropriate site(s) in the brain. Hence, the question of how the information about the external world is compressed in the retina and how this compressed representation is encoded into spike trains is of seminal importance. . . . The encoder/stimulator takes into account the irregular distribution of photoreceptors within the human retina and is able to encode the visual information in a way that is similar to the output of real retinal ganglion cells. Thus, the continuously varying input video steam is converted into neuromorphic pulse-coded signals through a circuit that emulates the function of retinal neurons.”
How human investigators are applying directly or indirectly what has been learned about synaptic network transmission to “bioinspired” medical devices is exciting and promising and reflects the awesome intelligence and design of our Creator God!