Temporal coding: Difference between revisions

Revision as of 23:00, 10 May 2012

Revision as of 23:59, 10 May 2012

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The specificity of temporal coding requires highly refined technology to measure informative, reliable, experimental data. Advances made in [[optogenetics]] allow neurologists to control spikes in individual neurons, offering electrical and spatial single-cell resolution. For example, blue light causes the light-gated ion channel [[channelrhodopsin]] to open, depolarizing the cell and producing a spike. When blue light is not sensed by the cell, the channel closes, and the neuron ceases to spike. The pattern of the spikes matches the pattern of the blue light stimuli. By inserting channelrhodopsin gene sequences into mouse DNA, researchers can control spikes and therefore certain behaviors of the mouse (e.g., making the mouse turn left).<ref name="youtube.com">Karl Diesseroth, Lecture. “Personal Growth Series: Karl Diesseroth on Cracking the Neural Code.” Google Tech Talks. November 21, 2008. http://www.youtube.com/watch?v=5SLdSbp6VjM</ref> Researchers, through optogenetics, have the tools to effect different temporal codes in a neuron while maintaining the same mean firing rate, and thereby can test whether or not temporal coding occurs in specific neural circuits.<ref name="Han X 2009">Han X, Qian X, Stern P, Chuong AS, Boyden ES. “Informational lesions: optical perturbations of spike timing and neural synchrony via microbial opsin gene fusions.” Cambridge, MA: MIT Media Lad, 2009. PubMed.</ref>

Optogenetic technology also has the potential to enable the correction of spike abnormalities at the root of several neurological and psychological disorders.<ref name="Han X 2009"/> If neurons do encode information in individual spike timing patterns, key signals could be missed by attempting to crack the code while looking only at mean firing rates.<ref name="Theunissen F 1995"/> Understanding any temporally encoded aspects of the neural code and replicating these sequences in neurons could allow for greater control and treatment of neurological disorders such as [[depression (mood)|depression]], [[Schizophreniaschizophrenia]], and [[Parkinson’s Diseasedisease]]. Regulation of spike intervals in single cells more precisely controls brain activity than the addition of pharmacological agents intravenously.<ref name="youtube.com"/>

==See also==