Nonlinear Pattern Separation in Single Hippocampal Neurons with Active Dendritic Membrane

University of Texas San Antonio, TX 78285 The dendritic trees of cortical pyramidal neurons seem ideally suited to perfonn local processing on inputs. To explore some of the implications of this complexity for the computational power of neurons, we simulated a realistic biophysical model of a hippocampal pyramidal cell in which a "cold spot"-a high density patch of inhibitory Ca-dependent K channels and a colocalized patch of Ca channels-was present at a dendritic branch point. The cold spot induced a non monotonic relationship between the strength of the synaptic input and the probability of neuronal fIring. This effect could also be interpreted as an analog stochastic XOR.