46 results about "Presynaptic neuron" patented technology

In Pavlovian and instrumental conditioning, rewards typically come seconds after reward-triggering actions, creating an explanatory conundrum known as the distal reward problem or the credit assignment problem. How does the brain know what firing patterns of what neurons are responsible for the reward if (1) the firing patterns are no longer there when the reward arrives and (2) most neurons and synapses are active during the waiting period to the reward? A model network and computer simulation of cortical spiking neurons with spike-timing-dependent plasticity (STDP) modulated by dopamine (DA) is disclosed to answer this question. STDP is triggered by nearly-coincident firing patterns of a presynaptic neuron and a postsynaptic neuron on a millisecond time scale, with slow kinetics of subsequent synaptic plasticity being sensitive to changes in the extracellular dopamine DA concentration during the critical period of a few seconds after the nearly-coincident firing patterns. Random neuronal firings during the waiting period leading to the reward do not affect STDP, and hence make the neural network insensitive to this ongoing random firing activity. The importance of precise firing patterns in brain dynamics and the use of a global diffusive reinforcement signal in the form of extracellular dopamine DA can selectively influence the right synapses at the right time.

A synaptic circuit performing spike-timing dependent plasticity STDP interposed between a pre-synaptic neuron and a post-synapse neuron includes a memristor having a variable resistance value configured to receive a first signal from the pre-synaptic neuron. The circuit has an intermediate unit connected in series with the memristor for receiving a second signal from the pre-synaptic neuron and provides an output signal to the post-synaptic neuron. The intermediate unit receives a retroaction signal generated from the post-synaptic neuron and the memristor modifies the resistance value based on a delay between two at least partially overlapped input pulses, a spike event of the first signal and a pulse of the retroaction signal, in order to induct a potentiated state STP or a depressed state STD at the memristor. An electronic neuromorphic system having synaptic circuits and a method of performing spike timing dependent plasticity STDP by a synaptic circuit are also provided.

According to exemplary embodiments of the present disclosure, it is possible to provide method, system, arrangement, computer-accessible medium and device to stimulate individual neurons in brain slices in any arbitrary spatio-temporal pattern, using two-photon uncaging of photo-sensitive compounds such as MNI-glutamate and / or RuBi-Glutamate with beam multiplexing. Such exemplary method and device can have single-cell and three-dimensional precision. For example, by sequentially stimulating up to a thousand potential presynaptic neurons, it is possible to generate detailed functional maps of inputs to a cell. In addition, it is possible to combine this exemplary approach with two-photon calcium imaging in an all-optical method to image and manipulate circuit activity. Further exemplary embodiments of the present disclosure can include a light-weight, compact portable device providing for uses in a wide variety of applications.

A neuromorphic device may include: a plurality of pre-synaptic neurons; row lines extending in a row direction from the plurality of pre-synaptic neurons; a plurality of post-synaptic neurons; column lines extended in a column direction from the plurality of post-synaptic neurons; a plurality of synapses arranged at intersections between the row lines and the column lines; a plurality of first control blocks; and first control lines extending from the control blocks. The first control lines may be electrically connected to the plurality of synapses.

A neuromorphic device may include: a plurality of pre-synaptic neurons; row lines extending in a row direction from the plurality of pre-synaptic neurons; a plurality of post-synaptic neurons; column lines extended in a column direction from the plurality of post-synaptic neurons; a plurality of synapses arranged at intersections between the row lines and the column lines; a plurality of first control blocks; and first control lines extending from the control blocks. The first control lines may be electrically connected to the plurality of synapses.

An electronic neuronal circuit system to model the interaction between the postsynaptic terminal of a first synapse between two neurons and the postsynaptic terminal of a second synapse between two neurons includes comparators to model the presynaptic neurons of the synapses, plurality of three diodes connected to the comparators to model synapses, an AND gate and latch to model the formation of functional link between the postsynaptic terminals, and timer-controlled latches for controlling the life-span of the inter-postsynaptic functional link, durations of re-activation of inter-postsynaptic functional link and flow of activity through the output postsynaptic dendritic terminals.