PATCH-CLAMPING IN BRAIN-SLICES - SYNAPTIC TRANSMISSION FROM ATP TO LONG-TERM POTENTIATION

Application of patch-clamp techniques to brain slices has resulted in an enormous increase in the resolution of synaptic currents in mammali an central neurones. This improved resolution has allowed direct obser vation of miniature and evoked synaptic currents, leading, in agreemen t with other findings, to the conclusion that the quantal size of syna ptic currents in the brain is limited by the number of postsynaptic re ceptors. Possible explanations for the skewed miniature distribution, observed at all fast central synapses are discussed, with reference to anatomical observations. As a result, a model is proposed which is co nsistent with much of the apparently contradictory data on the inducti on and maintenance of long-term potentiation. In addition to the study of mechanisms of synaptic transmission, improved resolution provided by the patch-clamp technique has allowed resolution of synaptic curren ts, in the brain, mediated by ATP. The role of ATP as a central neurot ransmitter is discussed in terms of the above findings.