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Updated: Jul 9, 2026
09:40
Ballistic Labeling of Pyramidal Neurons in Brain Slices and in Primary Cell Culture
Published on: April 2, 2020
Dendritic properties of turtle pyramidal neurons
Matthew E Larkum1, Shigeo Watanabe, Nechama Lasser-Ross
1Department of Physiology, University of Bern, CH-3012, Bern, Switzerland. larkum@pyl.unibe.ch
Journal of Neurophysiology
|November 30, 2007
Summary
Studying turtle brains reveals fundamental cortical properties. Key features like spike backpropagation and calcium channels in pyramidal neurons are ancient traits conserved across species.
Area of Science:
- Neuroscience
- Comparative Neurology
- Evolutionary Biology
Background:
- The mammalian neocortex evolved from the reptilian paleocortex.
- Turtles retain a three-layered paleocortex, offering insights into fundamental cortical properties.
Purpose of the Study:
- To investigate the cellular and circuit properties of pyramidal neurons in the turtle cortex.
- To identify primitive traits of cortical function by examining turtle brain cellular properties.
Main Methods:
- Whole-cell recordings and calcium imaging were used in turtle cortical slices.
- Characterized dendritic properties, firing patterns, and intracellular calcium dynamics of pyramidal neurons.
Main Results:
- Somatic spikes actively backpropagate into dendrites, causing calcium changes, indicating primitive traits.
- Fast sodium spikes can initiate in dendrites; somatic "prepotentials" originate in the axon.
- Synaptic stimulation primarily causes calcium influx via voltage-gated channels, with some internal store release.
Conclusions:
- Spike backpropagation and dendritic calcium channels are primitive, conserved features of cortical pyramidal cells.
- Synaptically activated calcium release is also a fundamental, conserved cortical property.
- These conserved cellular properties are likely essential for basic cortical function across species.
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