Function of the central nervous system is based on mutual relations among the nerve cells. Description of nerve cells
and their processes, including their contacts was enabled by improvement of optical features of the microscope and
by the development of impregnation techniques. It is associated with the name of Antoni van Leeuwenhoek
(1632–1723), J. Ev. Purkyně (1787–1869), Camillo Golgi (1843–1926), and Ramón y Cajal (1852–1934). Principal
units of the neuronal network are the synapses. The term synapse was introduced into neurophysiology by Charles
Scott Sherrington (1857–1952). Majority of the interactions between nerve cells is mediated by neurotransmitters
acting at the receptors of the postsynaptic membrane or at the autoreceptors of the presynaptic part of the synapse.
Attachment of the vesicles to the presynaptic membrane and the release of the neurotransmitter into the synaptic cleft
depend on the intracellular calcium concentration and on the presence of several proteins in the presynaptic element.
J. Ev. Purkyně, neuron, neuronal network, synaps.