Electrical synapse Electrical synapse An electrical synapse is a mechanical and electrically conductive link between two neighboring neurons that is formed at a narrow gap between the pre- and postsynaptic neurons known as a gap junction. At gap junctions, such cells approach within about 3.8 nm of each other, a much shorter distance than the 20- to 40-nanometer distance that separates cells at chemical synapse. In many animals, electrical synapse-based systems co-exist with chemical synapses. Compared to chemical synapses, electrical synapses conduct nerve impulses faster, but, unlike chemical synapses, they lack gain—the signal in the postsynaptic neuron is the same or smaller
Process tomography imaging methods are used in process tomography, e.g. ultrasonic imaging, positron emission tomography (PET), electrical resistance tomography (ERT) and electrical impedance tomography (EIT), electrical capacitance tomography (ECT), magnetic induction tomography (MIT). In all cases external sensors are used to detect signals from boundary of the object, and the three-dimensional material distribution or the velocity field is computed using the measured data. Process tomography is an area of rapid growth both in terms of research and applications. There are number of challenges remaining in this area including data processing an image reconstruction, and application of imaging modalities in a real applications.