Properties of convergent thalamocortical and intracortical synaptic potentials in single neurons of neocortex (original) (raw)

We explored differences in the properties of convergent afferent inputs to single neurons in the barrel area of the neocortex. Thalamocortical slices were prepared from mature mice. Recordings were made from neurons in layer V, and either thalamocortical afferents or horizontal intracortical axons were stimulated. Monosynaptic EPSPs from both sources had latencies shorter than 1.8 msec and low shape variance. Disynaptic thalamocortical IPSPs had latencies longer than 1.8 msec. All neuronal types, as defined by intrinsic firing patterns, received both thalamocortical and intracortical monosynaptic input. The shape parameters (rate of rise and half-width) of monosynaptic EPSPs from the two inputs did not differ significantly. The rate of rise of EPSPs varied considerably across cells, but the rates of rise of thalamocortical and intracortical EPSPs onto single cells were strongly correlated.