Presentation on theme: "Neuron-based Communications Challenges Dr. Olga Kara Nano Communication Centre Department of Electronic and Communication Engineering Tampere University."— Presentation transcript:
Neuron-based Communications Challenges Dr. Olga Kara Nano Communication Centre Department of Electronic and Communication Engineering Tampere University of Technology
Neuron-based communication in Neurotechnology Robotics Human spare parts Human-computer interaction Information technology Effective resource management Self-organization Memory storage and retrieval Neurotechnology is an integration of neurobiology with information technology and engineering
Robotics and nanorobotics – Robotic vision is one of the most complex sensory system that takes around 1/3 of human cortex – Robotic today need camera and huge computational power – Neurons simplify visual processing, by compressing information at the source and apply specific encodings in a form of spikes. – To resolve the problem of high speed motor control – Decision making-The complex network of single biological nano-units – neurons able to solve the complex problems in milliseconds by separating the problem into small problem and resolving them without understanding of global picture.
Bionics - robotic spare parts
Nanorobotics Neurodust by Michel Maharbiz from Berkeley We need some system that will be able to record simultaneously thousands of individual neurons in multiple brain areas. Communication??? Dr. Michel Maharbiz: Neural dust system diagram showing the placement of ultrasonic interrogator under the skull and the independent neural dust sensing nodes dispersed throughout the brain. Source: arXiv: v1 Read more at:
Human Computer Interaction Information System Research – Microsoft – research on the potential of neuroscience Cognition Usability engineering (implement real-time ergonomic for adaptive fitting of the task to the user). Embedded nanodevices? Artificial intelligence (neurochip with real neurons instead of computer components?) Diagnostic and monitoring
Information processing Neuron networks perform effective information processing and transfer Information coding, transfer and decoding Information theory – Neural system as a communication channel – Neural coding: how the activity of neuron (measured as output) represent input? – When neurons face with new information they will try to develop a strategy to encode this information and store it for later usage. – The mechanism of information compression…
Sensory information processing performed on many levels Information processing
Neural circuits Neurons are interconnected with one another to form circuits with dense synaptic connectivity to process specific information. Circuits regulate itself by feedback loop. Many neural circuits together form a neural system (as many electronic circuits together form a computer) Afferent (sender) Interneuron - modulator with inhibitory properties Efferent (receiver) - carry information away from the cell body
Information coding Information transmission Information receiving Information decoding SyntesisReleaseReceptionProcessing
Information processing in postsynaptic neuron (receiver)
Resource management Effective resource management in the brain – Two targets can be processed simultaneously even in a limited information capacity situation – T1 – presented first and occupied short term memory for 500ms, T2 may not be seen Brain can be adjusted by training the neurons to effectively distribute brain resources
Self-organization, adaptation and learning Neurons self-organized in an effective communication network during the development Communication within and between network parties – Principles and mechanism of this process will help to develop effective communication network between nano devices
Neuronal plasticity Neuronal plasticity is a fundamental property of the neuronal tissue. This enables learning and adaptation. Activity in neurons can strengthen or weaken signalling at a synapse. High activity of neuron leads to recruitment of more axon terminals from the same neuron. Reduced activity leads to loss of synapses. If two synapses are active at the same time, the strength of the postsynaptic response may increase at both synapses, mediated by long-term potentiation. Long-term potentiation (LTP) is a long-lasting enhancement in signal transmission between two neurons as a results of synchronous stimulation LTP plays a major role in memory formation, that thought to be related to the modification of synaptic strength
Memory Memory is attributed to strengthened synaptic connections among particular brain neurons, yet synaptic membrane components are transient, whereas memories can endure. This suggests synaptic information is encoded and hard-wired elsewhere, e.g. at molecular levels within the post-synaptic neuron.
Memory storage and retrieval memory is the process in which information is encoded, stored, and retrieved. Encoding or registration: receiving, processing and combining of received information Storage: creation of a permanent record of the encoded information Retrieval, recall or recollection: calling back the stored information in response to some cue for use in a process or activity 1 Sensory memory 2 Short-term memory 3 Long-term memory Atkinson-Shiffrin model
Cytoskeleton Cytoskeleton : actin filaments, microtubuline and intermediate filaments establish the form of neuron, maintains synaptic connections. It is a part of eukaryotic (absent in bacteria) cells cytoskeleton. In the brain tubulin account for 10-20% of all soluble proteins. Microtubules are hollow tubes formed from tubulin molecules Microtubule is electrically polar structures composed of α and β subunits (which can be a different subtypes, located at different parts of the cell and involved in different functions (mutation may lead to a loss of some specific function (sensitivity in nematode)).
Microtubules Microtubules are dynamically instable and undergo rapid cycles of growth and shrinkage Microtubules constructed of α/β heterodimers (α and β subunits of tubuline) that compose a protofilament s, and form a hollow tubule (24 nm) α-tubuline is bound to DTP β is bound to GDP in microtubule (as it will hydrolyze from GPT to GDP during the binding process). The β tubuline + GTP at the end is called GTP cup that will be hydrolysed by binding – the rescue process. If GTP at the end hydrolysed without binding the shrinkage will occur - catastrophe The number of protofilaments can be different from 10 to 15. In mammalian cells is usually 13 Microtubules are interconnected by linking proteins (microtubule-associated proteins: MAPs) to other microtubules and cell structures to form cytoskeletal lattice networks Microtubule dynamics – growth and shrinkage rates, – rescue and catastrophe frequencies, – sometimes supplemented by pause duration. MT formation can be regulated by calcium signals