Maturation of layer 5 neocortical pyramidal neurons: amplifying salient layer 1 and layer 4 inputs by Ca2+ action potentials in adult rat tuft dendrites

Zhu, J. J. (August 2000) Maturation of layer 5 neocortical pyramidal neurons: amplifying salient layer 1 and layer 4 inputs by Ca2+ action potentials in adult rat tuft dendrites. Journal of Physiology, 526 (3). pp. 571-587. ISSN 0022-3751

Abstract

1. Changes in the arborization and electrical excitability of the apical dendritic tufts of pyramidal cells of cortical layer 5 were examined during the first 2 months (postnatal days (P)2-56) of postnatal development in rats. 2. Rt constructions of biocytin-filled neurons showed that the apical dendritic trunk was continually growing, becoming longer and thicker and that the distance between the tuft. and soma increased more than 5-fold, 3. In P2 animals, both the tuft and soma had a high input, resistance (> 500 M Omega) and the tuft was electrotonically close to the some. In contrast, the apical tuft and soma of P56 neurons had a low input resistance (< 50 M Omega) and they were electrotonically isolated From each other. 4. Depolarizing current pulses injected into the tuft of P2 cells generated mostly Na+-dependent regenerative dendritic potentials of short duration (similar to 15 ms) while in the tuft of P56 animals, complex regenerative potentials were generated which had a longer duration (similar to 55 ms) and were Na+ and Ca2+ dependent. In young and juvenile animals (P14-28) dendritic regenerative potentials could br restricted tu the apical dendritic tuft whereas in adult animals (> P42), the: complex regenerative potentials frequently occurred simultaneously wit ll somatic action potentials. 5. The main developmental change in layer 5 pyramidal neurons, as assayed with square pulse current injections and synaptic stimulations, is the progressive electrotonic isolation of thr: dendritic tuft from the soma. This change is concomitant with that the appearance of complex, mostly Na+- and Ca2+-dependent, regenerative dendritic potentials initiated partly in the tuft and partly in the axon. The coupling of the dendritic tuft and axonal initiation zones for regenerative potentials by active dendritic Na+ and Ca2+ conductances enables mature layer 5 pyramidal neurons to detect selectively the salient distal synaptic inputs and coincident synaptic inputs arriving at different cortical layers.

Item Type: Paper
Uncontrolled Keywords: PRIMARY SOMATOSENSORY CORTEX LATERAL GENICULATE-NUCLEUS INTRINSIC FIRING PATTERNS APICAL DENDRITES VISUAL-CORTEX ELECTROPHYSIOLOGICAL PROPERTIES CHOLINERGIC INNERVATION SYNAPTIC PHYSIOLOGY SENSORIMOTOR CORTEX CEREBRAL-CORTEX
Subjects: organs, tissues, organelles, cell types and functions > tissues types and functions > cerebral cortex
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic arbors
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic arbors
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic arbors
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic spines
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic spines
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > dendritic cells > dendritic spines
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons > pyramidal neurons
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons > pyramidal neurons
organs, tissues, organelles, cell types and functions > cell types and functions > cell types > neurons > pyramidal neurons
CSHL Authors:
Communities: CSHL labs > Malinow lab
Depositing User: Matt Covey
Date: August 2000
Date Deposited: 30 Jan 2014 21:05
Last Modified: 30 Jan 2014 21:05
PMCID: PMC2270034
Related URLs:
URI: https://repository.cshl.edu/id/eprint/29416

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