Greg J. Stuart

Learn More
The dendrites of neurons in the mammalian central nervous system have been considered as electrically passive structures which funnel synaptic potentials to the soma and axon initial segment, the site of action potential initiation. More recent studies, however, have shown that the dendrites of many neurons are not passive, but contain active conductances.(More)
The temporal and spatial profile of activity-evoked changes in membrane potential and intracellular calcium concentration in the dendrites of hippocampal CA1 pyramidal neurons was examined with simultaneous somatic and dendritic patch-pipette recording and calcium imaging experiments. Action potentials are initiated close to the soma of these neurons and(More)
A description is given of the implementation of infrared differential interference contrast (IR-DIC) video microscopy to an upright compound microscope. Using the improved resolution offered by IR-DIC a procedure is described for making patch-pipette recordings from visually identified neuronal somata and dendrites in brain slices. As an example of the(More)
How effectively synaptic and regenerative potentials propagate within neurons depends critically on the membrane properties and intracellular resistivity of the dendritic tree. These properties therefore are important determinants of neuronal function. Here we use simultaneous whole-cell patch-pipette recordings from the soma and apical dendrite of(More)
1. Initiation and propagation of action potentials evoked by extracellular synaptic stimulation was studied using simultaneous dual and triple patch pipette recordings from different locations on neocortical layer 5 pyramidal neurons in brain slices from 4-week-old rats (P26-30) at physiological temperatures. 2. Simultaneous cell-attached and whole-cell(More)
1. Simultaneous whole-cell voltage and Ca2+ fluorescence measurements were made from the distal apical dendrites and the soma of thick tufted pyramidal neurons in layer 5 of 4-week-old (P28-32) rat neocortex slices to investigate whether activation of distal synaptic inputs can initiate regenerative responses in dendrites. 2. Dual whole-cell voltage(More)
Action potentials are binary signals that transmit information via their rate and temporal pattern. In this context, the axon is thought of as a transmission line, devoid of a role in neuronal computation. Here, we show a highly localized role of axonal Kv1 potassium channels in shaping the action potential waveform in the axon initial segment (AIS) of(More)
The specific membrane capacitance (C(m)) of a neuron influences synaptic efficacy and determines the speed with which electrical signals propagate along dendrites and unmyelinated axons. The value of this important parameter remains controversial. In this study, C(m) was estimated for the somatic membrane of cortical pyramidal neurons, spinal cord neurons,(More)
Most neurons in the mammalian CNS encode and transmit information via action potentials. Knowledge of where these electrical events are initiated and how they propagate within neurons is therefore fundamental to an understanding of neuronal function. While work from the 1950s suggested that action potentials are initiated in the axon, many subsequent(More)
The axon initial segment (AIS) is a specialized region in neurons where action potentials are initiated. It is commonly assumed that this process requires a high density of voltage-gated sodium (Na(+)) channels. Paradoxically, the results of patch-clamp studies suggest that the Na(+) channel density at the AIS is similar to that at the soma and proximal(More)