High resolution

Module 10: Figure miniature EPSCs

Activation of presynaptic transmitter release by metabotropic receptor activation.

The spontaneous miniature excitatory postsynaptic currents (mEPSCs) from layer II neurons of the barrel cortex were used to monitor transmitter release. The traces in A show the control rate. Following activation of the metabotropic receptors, there was a marked increase in frequency, as shown in B. It is proposed that this increase in frequency is due to the release of Ca2+ from the internal store within the presynaptic ending (Module 10: Figure neocortical Ca2+ release). Reproduced from Simkus, C.R.L. and Stricker, C. (2002) The contribution of intracellular calcium stores to mEPSCs recorded in layer II neurones of rat barrel cortex. J. Physiol. 545:521–535, with permission from Blackwell Publishing; see Simkus and Stricker 2002.