Cultured neuronal network
Encyclopedia
A cultured neuronal network is a cell culture
of neurons that is used as a model to study the central nervous system
, especially the brain
. Often, cultured neuronal networks are connected to an input/output device such as a multi-electrode array (MEA), thus allowing two-way communication between the researcher and the network. This model has proved to be an invaluable tool to scientists studying the underlying principles behind neuronal learning
, memory
, plasticity
, connectivity
, and information processing
.
Cultured neurons are often connected via computer to a real or simulated robotic component, creating a hybrot
or animat
, respectively. Researchers can then thoroughly study learning and plasticity in a realistic context, where the neuronal networks are able to interact with their environment and receive at least some artificial sensory feedback. One example of this can be seen in the Multielectrode Array Art
(MEART) system developed by the Potter Research Group at the Georgia Institute of Technology
in collaboration with the Symbi-oticA Research Group at the University of Western Australia
. Another example can be seen in the neurally controlled animat
.
A cultured neuronal network allows researchers to observe neuronal activity from several vantage points. Electrophysiological
recording and stimulation can take place either across the network or locally via an MEA, and the network development can be visually observed using microscopy techniques. Moreover, chemical analysis of the neurons and their environment is more easily accomplished than in an in vivo setting.
from a fetus and are therefore disrupted at a critical stage in network development. When the neurons are suspended in solution and subsequently dispensed, the connections previously made are destroyed and new ones formed. Ultimately, the connectivity (and consequently the functionality) of the tissue is changed from what the original template suggested.
Another disadvantage lies in the fact that the cultured neurons lack a body and are thus severed from sensory input as well as the ability to express behavior – a crucial characteristic in learning and memory experiments. It is believed that such sensory deprivation has adverse effects on the development of these cultures and may result in abnormal patterns of behavior throughout the network.
Cultured networks on traditional MEAs are flat, single-layer sheets of cells with connectivity only two dimensions. Most in vivo neuronal systems, to the contrary, are large three-dimensional structures with much greater interconnectivity. This remains one of the most striking differences between the model and the reality, and this fact probably plays a large role in skewing some of the conclusions derived from experiments based on this model.
, hippocampal
, and spinal neurons
, although lab mouse neurons have also been used. Currently, relatively little research has been conducted on growing primate or other animal neuronal networks. Harvesting neural stem cells requires sacrificing the developing fetus, a process considered too costly to perform on many mammals that are valuable in other studies.
One study, however, did make use of human neural stem cells grown into a network to control a robotic actuator. These cells were acquired from a fetus that spontaneously aborted after ten weeks in gestation
. They are also susceptible to hyperosmolality from medium
evaporation. The long timelines associated with studying neuronal plasticity (usually on the scale of months) makes extending the lifespan of neurons in vitro paramount.
One solution to this problem involves growing cells on an MEA inside a sealed chamber. This chamber serves as a non-humidified incubator that is enclosed by a fluorinated ethylene propylene
(FEP) membrane that is permeable to select gases (i.e. gases necessary for metabolism) but impermeable to water and microbes. Other solutions entail an incubator with an impermeable membrane that has a specific mix of gases (air with 5% CO2 is typical) sealed inside.
This device has been an essential biosensor for more than thirty years. It has been used not only in the study of neuronal plasticity and information processing but also in drug
and toxin
effects on neurons. Additionally, when coupled with a sealed incubation chamber this device greatly reduces the risk of culture contamination by nearly eliminating the need to expose it to air.
Currently, commonly used MEAs have relatively poor spatial resolution. They employ approximately sixty electrodes for recording and stimulation in varying patterns in a dish with a typical culture of 50,000 cells or more (or a density of 5,000 cells/mm2). It follows that each electrode in the array services a large cluster of neurons and cannot provide resolute information regarding signal origin and destination; such MEAs are only capable of region-specific data acquisition and stimulation.
Ideally it would be possible to record and stimulate from a single or a few neurons at a time. Indeed, companies such as Axion Biosystems are working to provide MEAs with much higher spatial resolution to this end (a maximum of 768 input/output electrodes). Another study investigates establishing a stable one-to-one connection between neurons and electrodes. The goal was to meet the ideal interface situation by establishing a correspondence with every neuron in the network. They do so by caging individual neurons while still allowing the axons and dendrites to extend and make connections. Neurons are contained within ‘’neurocages’’, and the device itself is referred to as the caged neuron MEA or neurochip
.
Other research suggests alternative techniques to stimulating neurons in vitro. One study investigates the use of a laser
beam to free caged compounds such as neurotransmitters and neuromodulators. A laser beam with wavelength in the UV
spectrum would have extremely high spatial accuracy and, by releasing the caged compounds, could be used to influence a very select set of neurons.
Depending on experimental perspective, network-wide bursts can be viewed either positively or negatively. In a pathological sense, spontaneous network activity can be attributed to the disembodiment of the neurons; one study saw a marked difference between array-wide firing frequency in cultures that received continuous input versus those that did not. To eliminate abhorrent activity, researchers commonly use magnesium
or synaptic blockers to quiet the network. However, this approach has great costs; quieted networks have little capacity for plasticity due to a diminished ability to create action potentials. A different and perhaps more effective approach is the use of low frequency stimulation that emulates sensory background activity.
In a different light, network bursts can be thought of as benign and even good. Any given network demonstrates non-random, structured bursts. Some studies have suggested that these bursts represent information carriers, expression of memory, a means for the network to form appropriate connections, and learning when their pattern changes.
cells, the AWSR has long rise and fall times during early development and sharper, more intense profiles after approximately 25 DIV. However, the use of BPs has an inherent shortcoming; BPs are an average of all network activity over time, and therefore only contain temporal information. In order to attain data about the spatial pattern of network activity they developed what they call phase profiles (PPs), which contain electrode specific data.
Data was gathered using these PPs on timescales of milliseconds up through days. . Their goal was to establish the stability of network burst profiles on the timescale of minutes to hours and to establish stability or developmental changes over the course of days. In summary, they were successful in demonstrating stability over minutes to hours, but the PPs gathered over the course of days displayed significant variability. These finding imply that studies of plasticity of neurons can only be conducted over the course of minutes or hours without bias in network activity introduced by normal development .
and plasticity
. One definition suggests that learning is “the acquisition of novel behavior through experience”. Corollary to this argument is the necessity for interaction with the environment around it, something that cultured neurons are virtually incapable of without sensory systems. Plasticity, on the other hand, is simply the reshaping of an existing network by changing connections between neurons: formation and elimination of synapses or extension and retraction of neurites and dendritic spines. But these two definitions are not mutually exclusive; in order for learning to take place, plasticity must also take place.
In order to establish learning in a cultured network, researchers have attempted to re-embody the dissociated neuronal networks in either simulated or real environments (see MEART
and animat
). Through this method the networks are able to interact with their environment and, therefore, have the opportunity to learn in a more realistic setting. Other studies have attempted to imprint signal patterns onto the networks via artificial stimulation. This can be done by inducing network bursts or by inputing specific patterns to the neurons, from which the network is expected to derive some meaning (as in experiments with animats, where an arbitrary signal to the network indicates that the simulated animal has run into a wall or is moving in a direction, etc.). The latter technique attempts to take advantage of the inherent ability of neuronal networks to make sense of patterns. However, experiments have had limited success in demonstrating a definition of learning that is widely agreed upon. Nevertheless, plasticity in neuronal networks is a phenomenon that is well-established in the neuroscience community, and one that is thought to play a very large role in learning.
Cell culture
Cell culture is the complex process by which cells are grown under controlled conditions. In practice, the term "cell culture" has come to refer to the culturing of cells derived from singlecellular eukaryotes, especially animal cells. However, there are also cultures of plants, fungi and microbes,...
of neurons that is used as a model to study the central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
, especially the brain
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
. Often, cultured neuronal networks are connected to an input/output device such as a multi-electrode array (MEA), thus allowing two-way communication between the researcher and the network. This model has proved to be an invaluable tool to scientists studying the underlying principles behind neuronal learning
Learning
Learning is acquiring new or modifying existing knowledge, behaviors, skills, values, or preferences and may involve synthesizing different types of information. The ability to learn is possessed by humans, animals and some machines. Progress over time tends to follow learning curves.Human learning...
, memory
Memory
In psychology, memory is an organism's ability to store, retain, and recall information and experiences. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing memory....
, plasticity
Neuroplasticity
Neuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment. Plasticity occurs on a variety of levels, ranging from cellular changes involved in...
, connectivity
Synapse
In the nervous system, a synapse is a structure that permits a neuron to pass an electrical or chemical signal to another cell...
, and information processing
Information processing
Information processing is the change of information in any manner detectable by an observer. As such, it is a process which describes everything which happens in the universe, from the falling of a rock to the printing of a text file from a digital computer system...
.
Cultured neurons are often connected via computer to a real or simulated robotic component, creating a hybrot
Hybrot
A hybrot is a cybernetic organism in the form of a robot controlled by a computer consisting of both electronic and biological elements. The biological elements are typically rat neurons connected to a computer chip....
or animat
Animat
Animats are artificial animals, a contraction of anima-materials. The term includes physical robots and virtual simulations. Animat research, a subset of Artificial Life studies, has become rather popular since Rodney Brooks' seminal paper "Intelligence without representation". The word was coined...
, respectively. Researchers can then thoroughly study learning and plasticity in a realistic context, where the neuronal networks are able to interact with their environment and receive at least some artificial sensory feedback. One example of this can be seen in the Multielectrode Array Art
Hybrot
A hybrot is a cybernetic organism in the form of a robot controlled by a computer consisting of both electronic and biological elements. The biological elements are typically rat neurons connected to a computer chip....
(MEART) system developed by the Potter Research Group at the Georgia Institute of Technology
Georgia Institute of Technology
The Georgia Institute of Technology is a public research university in Atlanta, Georgia, in the United States...
in collaboration with the Symbi-oticA Research Group at the University of Western Australia
University of Western Australia
The University of Western Australia was established by an Act of the Western Australian Parliament in February 1911, and began teaching students for the first time in 1913. It is the oldest university in the state of Western Australia and the only university in the state to be a member of the...
. Another example can be seen in the neurally controlled animat
Animat
Animats are artificial animals, a contraction of anima-materials. The term includes physical robots and virtual simulations. Animat research, a subset of Artificial Life studies, has become rather popular since Rodney Brooks' seminal paper "Intelligence without representation". The word was coined...
.
Advantages
The use of cultured neuronal networks as a model for their in vivo counterparts has been an indispensable resource for decades. It allows researchers to investigate neuronal activity in a much more controlled environment than would be possible in a live organism. Through this mechanism researchers have gleaned important information about the mechanisms behind learning and memory.A cultured neuronal network allows researchers to observe neuronal activity from several vantage points. Electrophysiological
Electrophysiology
Electrophysiology is the study of the electrical properties of biological cells and tissues. It involves measurements of voltage change or electric current on a wide variety of scales from single ion channel proteins to whole organs like the heart...
recording and stimulation can take place either across the network or locally via an MEA, and the network development can be visually observed using microscopy techniques. Moreover, chemical analysis of the neurons and their environment is more easily accomplished than in an in vivo setting.
Disadvantages
Cultured neuronal networks are by definition disembodied cultures of neurons. Thus by being outside their natural environment, the neurons are influenced in ways that are not biologically normal. Foremost among these abnormalities is the fact that the neurons are usually harvested as neural stem cellsNeurogenesis
Neurogenesis is the process by which neurons are generated from neural stem and progenitor cells. Most active during pre-natal development, neurogenesis is responsible for populating the growing brain with neurons. Recently neurogenesis was shown to continue in several small parts of the brain of...
from a fetus and are therefore disrupted at a critical stage in network development. When the neurons are suspended in solution and subsequently dispensed, the connections previously made are destroyed and new ones formed. Ultimately, the connectivity (and consequently the functionality) of the tissue is changed from what the original template suggested.
Another disadvantage lies in the fact that the cultured neurons lack a body and are thus severed from sensory input as well as the ability to express behavior – a crucial characteristic in learning and memory experiments. It is believed that such sensory deprivation has adverse effects on the development of these cultures and may result in abnormal patterns of behavior throughout the network.
Cultured networks on traditional MEAs are flat, single-layer sheets of cells with connectivity only two dimensions. Most in vivo neuronal systems, to the contrary, are large three-dimensional structures with much greater interconnectivity. This remains one of the most striking differences between the model and the reality, and this fact probably plays a large role in skewing some of the conclusions derived from experiments based on this model.
Neurons Used
Because of their wide availability, neuronal networks are typically cultured from dissociated rat neurons. Studies commonly employ rat corticalCerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...
, hippocampal
Hippocampus
The hippocampus is a major component of the brains of humans and other vertebrates. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation. Humans and other mammals have two hippocampi, one in...
, and spinal neurons
Spinal nerve
The term spinal nerve generally refers to a mixed spinal nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body...
, although lab mouse neurons have also been used. Currently, relatively little research has been conducted on growing primate or other animal neuronal networks. Harvesting neural stem cells requires sacrificing the developing fetus, a process considered too costly to perform on many mammals that are valuable in other studies.
One study, however, did make use of human neural stem cells grown into a network to control a robotic actuator. These cells were acquired from a fetus that spontaneously aborted after ten weeks in gestation
Long-Term Culture
One of the most formidable problems associated with cultured neuronal networks is their lack of longevity. Like most cell cultures, neuron cultures are highly susceptible to infectionInfection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
. They are also susceptible to hyperosmolality from medium
Growth medium
A growth medium or culture medium is a liquid or gel designed to support the growth of microorganisms or cells, or small plants like the moss Physcomitrella patens.There are different types of media for growing different types of cells....
evaporation. The long timelines associated with studying neuronal plasticity (usually on the scale of months) makes extending the lifespan of neurons in vitro paramount.
One solution to this problem involves growing cells on an MEA inside a sealed chamber. This chamber serves as a non-humidified incubator that is enclosed by a fluorinated ethylene propylene
Fluorinated ethylene propylene
Fluorinated ethylene propylene or FEP is a copolymer of hexafluoropropylene and tetrafluoroethylene. It differs from the PTFE resins in that it is melt-processible using conventional injection molding and screw extrusion techniques. Fluorinated ethylene propylene was invented by DuPont and is sold...
(FEP) membrane that is permeable to select gases (i.e. gases necessary for metabolism) but impermeable to water and microbes. Other solutions entail an incubator with an impermeable membrane that has a specific mix of gases (air with 5% CO2 is typical) sealed inside.
Multi-electrode Arrays (MEAs)
A multi-electrode array (MEA), also commonly called a microelectrode array, is a patterned array of electrodes laid out in a transparent substrate used for communication with neurons in contact with it. The communication can be, and usually is, bidirectional; researchers can both record electrophysiological data from a live network and stimulate it with a number of patterns.This device has been an essential biosensor for more than thirty years. It has been used not only in the study of neuronal plasticity and information processing but also in drug
Drug
A drug, broadly speaking, is any substance that, when absorbed into the body of a living organism, alters normal bodily function. There is no single, precise definition, as there are different meanings in drug control law, government regulations, medicine, and colloquial usage.In pharmacology, a...
and toxin
Neurotoxin
A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
effects on neurons. Additionally, when coupled with a sealed incubation chamber this device greatly reduces the risk of culture contamination by nearly eliminating the need to expose it to air.
Currently, commonly used MEAs have relatively poor spatial resolution. They employ approximately sixty electrodes for recording and stimulation in varying patterns in a dish with a typical culture of 50,000 cells or more (or a density of 5,000 cells/mm2). It follows that each electrode in the array services a large cluster of neurons and cannot provide resolute information regarding signal origin and destination; such MEAs are only capable of region-specific data acquisition and stimulation.
Ideally it would be possible to record and stimulate from a single or a few neurons at a time. Indeed, companies such as Axion Biosystems are working to provide MEAs with much higher spatial resolution to this end (a maximum of 768 input/output electrodes). Another study investigates establishing a stable one-to-one connection between neurons and electrodes. The goal was to meet the ideal interface situation by establishing a correspondence with every neuron in the network. They do so by caging individual neurons while still allowing the axons and dendrites to extend and make connections. Neurons are contained within ‘’neurocages’’, and the device itself is referred to as the caged neuron MEA or neurochip
Neurochip
A neurochip is a chip that is designed for the interaction with neuronal cells.- Formation :It is made of silicon that is doped in such a way that it contains EOSFETs that can sense the electrical activity of the neurons in the above-standing physiological electrolyte solution...
.
Other research suggests alternative techniques to stimulating neurons in vitro. One study investigates the use of a laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
beam to free caged compounds such as neurotransmitters and neuromodulators. A laser beam with wavelength in the UV
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
spectrum would have extremely high spatial accuracy and, by releasing the caged compounds, could be used to influence a very select set of neurons.
Spontaneous Network Activity
Spontaneous network bursts are a commonplace feature of neuronal networks both in vitro and in vivo. In vitro, this activity is particularly important in studies on learning and plasticity. Such experiments look intensely at the network-wide activity both before and after experiments in order to discern any changes that might implicate plasticity or even learning. However, confounding this experimental technique is the fact that normal neuronal development induces change in array-wide bursts that could easily skew data. In vivo, however, it has been suggested that these network bursts may form the basis for memories.Depending on experimental perspective, network-wide bursts can be viewed either positively or negatively. In a pathological sense, spontaneous network activity can be attributed to the disembodiment of the neurons; one study saw a marked difference between array-wide firing frequency in cultures that received continuous input versus those that did not. To eliminate abhorrent activity, researchers commonly use magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
or synaptic blockers to quiet the network. However, this approach has great costs; quieted networks have little capacity for plasticity due to a diminished ability to create action potentials. A different and perhaps more effective approach is the use of low frequency stimulation that emulates sensory background activity.
In a different light, network bursts can be thought of as benign and even good. Any given network demonstrates non-random, structured bursts. Some studies have suggested that these bursts represent information carriers, expression of memory, a means for the network to form appropriate connections, and learning when their pattern changes.
Array-Wide Burst Stability
Stegenga et al. set out to establish the stability of spontaneous network bursts as a function of time. They saw bursts throughout the lifetime of the cell cultures, beginning at 4–7 days in vitro (DIV) and continuing until culture death. They gathered network burst profiles (BPs) through a mathematical observation of array-wide spiking rate (AWSR), which is the summation of action potentials over all electrodes in an MEA. This analysis yielded the conclusion that, in their culture of Wistar rat neocorticalNeocortex
The neocortex , also called the neopallium and isocortex , is a part of the brain of mammals. It is the outer layer of the cerebral hemispheres, and made up of six layers, labelled I to VI...
cells, the AWSR has long rise and fall times during early development and sharper, more intense profiles after approximately 25 DIV. However, the use of BPs has an inherent shortcoming; BPs are an average of all network activity over time, and therefore only contain temporal information. In order to attain data about the spatial pattern of network activity they developed what they call phase profiles (PPs), which contain electrode specific data.
Data was gathered using these PPs on timescales of milliseconds up through days. . Their goal was to establish the stability of network burst profiles on the timescale of minutes to hours and to establish stability or developmental changes over the course of days. In summary, they were successful in demonstrating stability over minutes to hours, but the PPs gathered over the course of days displayed significant variability. These finding imply that studies of plasticity of neurons can only be conducted over the course of minutes or hours without bias in network activity introduced by normal development .
Learning vs. Plasticity
There is much controversy in the field of neuroscience surrounding whether or not a cultured neuronal network can learn. A crucial step in finding the answer to this problem lies in establishing the difference between learningLearning
Learning is acquiring new or modifying existing knowledge, behaviors, skills, values, or preferences and may involve synthesizing different types of information. The ability to learn is possessed by humans, animals and some machines. Progress over time tends to follow learning curves.Human learning...
and plasticity
Neuroplasticity
Neuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment. Plasticity occurs on a variety of levels, ranging from cellular changes involved in...
. One definition suggests that learning is “the acquisition of novel behavior through experience”. Corollary to this argument is the necessity for interaction with the environment around it, something that cultured neurons are virtually incapable of without sensory systems. Plasticity, on the other hand, is simply the reshaping of an existing network by changing connections between neurons: formation and elimination of synapses or extension and retraction of neurites and dendritic spines. But these two definitions are not mutually exclusive; in order for learning to take place, plasticity must also take place.
In order to establish learning in a cultured network, researchers have attempted to re-embody the dissociated neuronal networks in either simulated or real environments (see MEART
Hybrot
A hybrot is a cybernetic organism in the form of a robot controlled by a computer consisting of both electronic and biological elements. The biological elements are typically rat neurons connected to a computer chip....
and animat
Animat
Animats are artificial animals, a contraction of anima-materials. The term includes physical robots and virtual simulations. Animat research, a subset of Artificial Life studies, has become rather popular since Rodney Brooks' seminal paper "Intelligence without representation". The word was coined...
). Through this method the networks are able to interact with their environment and, therefore, have the opportunity to learn in a more realistic setting. Other studies have attempted to imprint signal patterns onto the networks via artificial stimulation. This can be done by inducing network bursts or by inputing specific patterns to the neurons, from which the network is expected to derive some meaning (as in experiments with animats, where an arbitrary signal to the network indicates that the simulated animal has run into a wall or is moving in a direction, etc.). The latter technique attempts to take advantage of the inherent ability of neuronal networks to make sense of patterns. However, experiments have had limited success in demonstrating a definition of learning that is widely agreed upon. Nevertheless, plasticity in neuronal networks is a phenomenon that is well-established in the neuroscience community, and one that is thought to play a very large role in learning.
See also
- Neurally Controlled AnimatNeurally controlled animatA Neurally Controlled Animat is the conjunction of#a cultured neuronal network#a virtual body, the Animat, "living" in a virtual computer generated environment, connected to this array...
- NeurochipNeurochipA neurochip is a chip that is designed for the interaction with neuronal cells.- Formation :It is made of silicon that is doped in such a way that it contains EOSFETs that can sense the electrical activity of the neurons in the above-standing physiological electrolyte solution...
- Brain-Computer InterfaceBrain-computer interfaceA brain–computer interface , sometimes called a direct neural interface or a brain–machine interface , is a direct communication pathway between the brain and an external device...
- CyberneticsCyberneticsCybernetics is the interdisciplinary study of the structure of regulatory systems. Cybernetics is closely related to information theory, control theory and systems theory, at least in its first-order form...
- Artificial LifeArtificial lifeArtificial life is a field of study and an associated art form which examine systems related to life, its processes, and its evolution through simulations using computer models, robotics, and biochemistry. The discipline was named by Christopher Langton, an American computer scientist, in 1986...
- NeuroplasticityNeuroplasticityNeuroplasticity is a non-specific neuroscience term referring to the ability of the brain and nervous system in all species to change structurally and functionally as a result of input from the environment. Plasticity occurs on a variety of levels, ranging from cellular changes involved in...
- Neural EnsembleNeural ensembleA neural ensemble is a population of nervous system cells involved in a particular neural computation.- Background :The concept of neural ensemble dates back to the work of Charles Sherrington who described the functioning of the CNS as the system of reflex arcs, each composed of interconnected...
- Neural EngineeringNeural engineeringNeural engineering is a discipline within biomedical engineering that uses engineering techniques to understand, repair, replace, enhance, or otherwise exploit the properties of neural systems...
- NeuroscienceNeuroscienceNeuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
- Artificial Neural Networks