Detailed Passive Cable Models of Whole-Cell Recorded CA3 Pyramidal Neurons in Rat Hippocampal Slices

摘要: Tight-seal whole-cell recordings were made from cleaned somata of CA3 pyramidal cells deep in hippocampal slices 19–21-d-old rats. The filled with biocytin, and their voltage responses to short current pulses recorded. After washout initial sag, scaled linearly injected stable over time. dendritic axonal arbors four reconstructed measured using light microscopy. Dendritic spines boutons counted the additional membrane area was incorporated into relevant segments. morphology each neuron converted a detailed branching cable model by assuming values for specific capacitance Cm resistance Rm, cytoplasmic resistivity Ri. These parameters optimized cell directly matching model's response that real means modified weighted least-squares fitting procedure. By comparing deviations between experimental control noise recordings, approximate 95% confidence intervals established parameter. If somatic shunt allowed, wide range possible Rm produced acceptable fits. With zero shunt, 0.7–0.8 microFcm-2, Ri 170–340 omega cm, ranged 120 200 k cm2. electrotonic lengths basal oblique dendrites 0.2–0.3 space constants, those apical tufts 0.4–0.7 constants. steady-state electrical geometry these therefore compact; average tip/soma relative synaptic efficacies > 93% dendrites, 81% tufts. fast transient inputs, however, models postsynaptic potential shapes marked filtering voltage-clamp currents.