517. Chen C. (2005) beta-Amyloid increases dendritic Ca2+ influx by inhibiting the A-type K+ current in hippocampal CA1 pyramidal neurons. Biochem Biophys Res Commun 338:1913-9.

NeuronCompartmentPropertyConnectivityNotes
Hippocampus CA1 pyramidal cellDistal apical dendriteI A.A-current is reduced in the presence of amyloid-beta (Chen C, 2005517 ). Patch-clamp recordings reveal a high density of A-type K channels in the dendritic tree, which increases with distance from the soma (Hoffman DA et al, 1997 [rat ]144 ). A shift toward more depolarized potentials of the activation curve has also been observed in mid and distal dendrites (more than 100um) (Hoffman DA et al, 1997 [rat ]144 ). These channels "prevent initiation of an action potential in the dendrites, limit the backpropagation of action potentials into the dendrites, and reduce excitatory synaptic events" (Hoffman DA et al, 1997 [rat ]144 ). Single action potential backpropagations show dichotomy of either strong attenuation (26-42%) or weak attenuation (71-87%). The dichotomy seems to be conferred primarily by differences in distribution, density, etc. of voltage dependent sodium and potassium channel (A-type, especially ) along the somatodendritic axis (Golding NL et al, 2001439 ) CA1 neurons and subiculum neurons in hippoampus differ in firing pattern (the former being regular and the later being either regular, weakly bursting or strongly bursting) and resting membrane properties (such as input restistance and membran time constant); however, low concentration of 4-AP (50 ?M) can convert neurons in both regions into firing bursting action potentials (Staff NP et al, 2000440 ).
Hippocampus CA1 pyramidal cellMiddle apical dendriteI A.A-current is reduced in the presence of amyloid-beta (Chen C, 2005517 ). Patch-clamp recordings reveal a high density of A-type K channels in the dendritic tree, which increases with distance from the soma (Hoffman DA et al, 1997 [rat ]144 ). A shift toward more depolarized potentials of the activation curve has also been observed in mid and distal dendrites (more than 100um) (Hoffman DA et al, 1997 [rat ]144 ). These channels "prevent initiation of an action potential in the dendrites, limit the backpropagation of action potentials into the dendrites, and reduce excitatory synaptic events" (Hoffman DA et al, 1997 [rat ]144 ). Single action potential backpropagations show dichotomy of either strong attenuation (26-42%) or weak attenuation (71-87%). The dichotomy seems to be conferred primarily by differences in distribution, density, etc. of voltage dependent sodium and potassium channel (A-type, especially ) along the somatodendritic axis (Golding NL et al, 2001439 ) CA1 neurons and subiculum neurons in hippoampus differ in firing pattern (the former being regular and the later being either regular, weakly bursting or strongly bursting) and resting membrane properties (such as input restistance and membran time constant); however, low concentration of 4-AP (50 µM) can convert neurons in both regions into firing bursting action potentials (Staff NP et al, 2000440 ).
Hippocampus CA1 pyramidal cellProximal apical dendriteI A.A-current is reduced in the presence of amyloid-beta (Chen C, 2005517 ). Patch-clamp recordings reveal a high density of A-type K channels in the dendritic tree, which increases with distance from the soma (Hoffman DA et al, 1997 [rat ]144 ). These channels "prevent initiation of an action potential in the dendrites, limit the backpropagation of action potentials into the dendrites, and reduce excitatory synaptic events" (Hoffman DA et al, 1997 [rat ]144 ). Single action potential backpropagations show dichotomy of either strong attenuation (26-42%) or weak attenuation (71-87%). The dichotomy seems to be conferred primarily by differences in distribution, density, etc. of voltage dependent sodium and potassium channel (A-type, especially ) along the somatodendritic axis (Golding NL et al, 2001439 ) CA1 neurons and subiculum neurons in hippoampus differ in firing pattern (the former being regular and the later being either regular, weakly bursting or strongly bursting) and resting membrane properties (such as input restistance and membran time constant); however, low concentration of 4-AP (50 µM) can convert neurons in both regions into firing bursting action potentials (Staff NP et al, 2000440 ).

References
517. Chen C. (2005) beta-Amyloid increases dendritic Ca2+ influx by inhibiting the A-type K+ current in hippocampal CA1 pyramidal neurons. Biochem Biophys Res Commun 338:1913-9.
144. Hoffman DA, Magee JC, Colbert CM and Johnston D. (1997) K+ channel regulation of signal propagation in dendrites of hippocampal pyramidal neurons. Nature 387:869-75.
439. Golding NL, Kath WL and Spruston N. (2001) Dichotomy of action-potential backpropagation in CA1 pyramidal neuron dendrites. J Neurophysiol 86:2998-3010 [Journal] .
440. Staff NP, Jung HY, Thiagarajan T, Yao M and Spruston N. (2000) Resting and active properties of pyramidal neurons in subiculum and CA1 of rat hippocampus. J Neurophysiol 84:2398-408 [Journal] .
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