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In the early 1950s, Eccles and his colleages performed the key experiments that would win Eccles the Nobel Prize. To study synapses in the periphrial nervous system, Eccles and colleagues used the stretch reflex as a model. This reflex is easily studied because it consists of only two neurons: a sensory neuron (the muscle spindle fiber) and the motor neuron. The sensory neuron synapses onto the motor neuron in the spinal cordThe spinal cord is a part of the vertebrate nervous system that is enclosed in and protected by the vertebral column (it passes through the spinal canal). It consists of nerve cells. The cord conveys the 31 spinal nerve pairs of the peripheral nervous sys. When Eccles passed a current into the sensory neruon in the quadricepsThe quadriceps femoris commonly the 'quadriceps', is a large muscle in the thigh, composed of the sections rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis. External link ., the motor neuron ennervating the quadricep produced a small excitatory postsynaptic potentialExcitatory Postsynaptic Potential is generally abbreviated to EPSP. Much information is available under the heading synapse but this is a different concept. References Also see: inhibitory postsynaptic potential dendrite neuron axon Nervous system. (EPSP). When he passed the same current through the hamstringIn human anatomy, the hamstrings are a group of muscles on the underside (posterior aspect) of the thigh. They are responsible for flexion of the knee, and all attach proximally to the ischial tuberosity. Because they attach to part of the hip, they also, the opposing muscle to the quadricep, he saw an inhibitory postsynaptic potentialInhibitory Postsynaptic Potential is commonly abbreviated to IPSP. Currently there is more information available under the heading synapse. References Also see: excitatory postsynaptic potential dendrite neuron axon Nervous system. (IPSP) in the quadricep motor neuron. Although a single EPSP was not enough to fire an action potentialelectrophysiological recording of an action potential showing the various phases which occur as the wave passes a point on a cell membrane. As the traveling signals of nerves and as the localized changes that contract muscle cells, action potentials are a in the motor neuron, the sum of several EPSPs from multiple sensory neurons synapsing onto the motor neuron could cause the motor neuron to fire, thus contracting the quadricep. On the other hand, IPSPs could subtract from this sum of EPSPs, preventing the motor neuron from firing.
Apart from these seminal experiments, Eccles was key to a number of important developments in neuroscienceNeuroscience is a field of study which deals with the structure, function, development, genetics, biochemistry, physiology, pharmacology and pathology of the nervous system. The study of behavior and learning is also a division of neuroscience. The biolog. Until around 1949, Eccles believed that synaptic transmission was primarily electrical rather than chemical. Although he was wrong in this hypothesis, his arguements led himself and others to perform some of the experiments which proved chemical synaptic transmission. Bernard Katz and Eccles worked together on some of the experiments which elucidated the role of acetylcholine as a neurotransmitter.