Microstimulation is a technique that stimulates a small population of
neuron
A neuron, neurone, or nerve cell is an electrically excitable cell that communicates with other cells via specialized connections called synapses. The neuron is the main component of nervous tissue in all animals except sponges and placozoa ...
s by passing a small
electrical current
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described b ...
through a nearby
microelectrode.
Applications
Microstimulation is used in
neuroanatomical
Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defi ...
research to identify the functional significance of a group of neurons. For example, Vidal-Gonzalez et al. (2006) applied microstimulation to the rat prelimbic and infralimbic subregions of the medial prefrontal cortex while testing the subjects in a fear-inducing low-footshock condition for various behavioral indicators of fear (such as freezing).
This test allowed them to compare the relative fear behavior of rats under microstimulation in either subregion to normal rats in the same condition. The researchers concluded that the prelimbic subregion excites fear behavior while the infralimbic subregion inhibits fear behavior. In this instance, the correlation between stimulation and behavior helped identify the function of these two subregions in the process of fear.
Microstimulation is being explored as a method to deliver sensory percepts to circumvent damaged sensory receptors or pathways. For example, stimulation of primary
visual cortex
The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus ...
create
phosphenes (flashes of light) which can be used to restore some vision for a blind individual. Other applications include bladder prostheses; cochlear and brain-stem auditory prostheses and retinal and thalamic visual prostheses.
References
Further reading
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* {{cite journal , last1=Flesher , first1=Sharlene N. , last2=Collinger , first2=Jennifer L. , last3=Foldes , first3=Stephen T. , last4=Weiss , first4=Jeffrey M. , last5=Downey , first5=John E. , last6=Tyler-Kabara , first6=Elizabeth C. , last7=Bensmaia , first7=Sliman J. , last8=Schwartz , first8=Andrew B. , last9=Boninger , first9=Michael L. , last10=Gaunt , first10=Robert A. , title=Intracortical microstimulation of human somatosensory cortex , journal=Science Translational Medicine , date=19 October 2016 , volume=8 , issue=361 , pages=361ra141 , doi=10.1126/scitranslmed.aaf8083 , pmid=27738096 , s2cid=4619069
Neurology