The temporal and spatial profile of activity-evoked changes in membrane potential intracellular calcium concentration the dendrites hippocampal CA1 pyramidal neurons was examined with simultaneous somatic dendritic patch-pipette recording imaging experiments. Action potentials are initiated close to soma these backpropagate into an activity-dependent manner; those occurring early a train propagate actively, whereas later fail actively invade distal dendrites. Consistent this finding,...

Initiation and propagation of action potentials evoked by extracellular synaptic stimulation was studied using simultaneous dual triple patch pipette recordings from different locations on neocortical layer 5 pyramidal neurons in brain slices 4‐week‐old rats (P26–30) at physiological temperatures. Simultaneous cell‐attached whole‐cell voltage the apical trunk (up to 700 μ m distal soma) soma indicated that proximal (layer 4) initiated first soma, whereas (upper 2/3) could initiate dendritic...

How effectively synaptic and regenerative potentials propagate within neurons depends critically on the membrane properties intracellular resistivity of dendritic tree. These therefore are important determinants neuronal function. Here we use simultaneous whole-cell patch-pipette recordings from soma apical dendrite neocortical layer 5 pyramidal to directly measure voltage attenuation in cortical neurons. When combined with morphologically realistic compartmental models same cells, data...

Simultaneous whole‐cell voltage and Ca 2+ fluorescence measurements were made from the distal apical dendrites soma of thick tufted pyramidal neurons in layer 5 4‐week‐old (P28–32) rat neocortex slices to investigate whether activation synaptic inputs can initiate regenerative responses dendrites. Dual recordings trunk primary tuft branches (540–940 μ m soma) showed that stimulation (upper 2) evoking a subthreshold depolarization at could potentials which either graded or all‐or‐none. These...

Neurons receive thousands of synaptic inputs throughout elaborate dendritic trees. Here we determine the somatic impact excitatory postsynaptic potentials (EPSPs) generated at known sites in neocortical pyramidal neurons. As became more distal, EPSP amplitude decreased, whereas use-dependent depression increased. Despite marked attenuation (>40-fold), when coactivated within a narrow time window (∼10 milliseconds), distal EPSPs could directly influence action potential output following...

Fundamental to an understanding of how neurons integrate synaptic input is the knowledge where within a neuron this information converted into output signal, action potential. Although it has been known for some time that potential initiation occurs axon neurons, precise location remained elusive. Here, we provide direct evidence using voltage-sensitive dyes site in cortical layer 5 pyramidal ∼35 μm from hillock. This was case during generation under variety conditions, after axonal...

Neocortical layer 5 pyramidal neurons possess long apical dendrites that receive a significant portion of the excitatory synaptic input. Passive neuronal models indicate time course postsynaptic potentials (EPSPs) generated in dendrite will be prolonged as they propagate toward soma. EPSP propagation may, however, influenced by recruitment dendritic voltage-activated channels. Here we investigate properties and distribution I(h) channels axon, soma, neocortical neurons, their effect on...

1 Electrophysiological recordings and pharmacological manipulations were used to investigate the mechanisms underlying generation of action potential burst firing its postsynaptic consequences in visually identified rat layer 5 pyramidal neurons vitro. 2 Based upon repetitive properties subthreshold membrane characteristics, separated into three classes: regular weak strong intrinsically firing. 3 High frequency (330 ± 10 Hz) was abolished or greatly weakened by removal Ca2+ (n= 5) from,...

Previous studies focusing on the temporal rules governing changes in synaptic strength during spike timing-dependent plasticity (STDP) have paid little attention to fact that inputs are distributed across complex dendritic trees. During STDP, propagation of action potentials (APs) back site input is thought trigger plasticity. However, pyramidal neurons, backpropagation single APs decremental, whereas high-frequency bursts lead generation distal calcium spikes. This raises question whether...

The hyperpolarization-activated cation current ( I h ) plays an important role in regulating neuronal excitability, yet its native single-channel properties the brain are essentially unknown. Here we use variance-mean analysis to study of single channels apical dendrites cortical layer 5 pyramidal neurons vitro . In these neurons, find that have average unitary conductance 680 ± 30 fS n = 18). Spectral simulated and showed there is little or no channel flicker below kHz. contrast uniformly...