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A novel approach to correlative studies of neuronal structure and function
E L White1, Y Amitai, M J Gutnick
1Department of Morphology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.
Israel Journal of Medical Sciences
|September 1, 1993
Summary
New electron microscopy techniques reveal that regular spiking (RS) and intrinsically bursting (IB) neurons have similar inhibitory synapse concentrations on their cell bodies. Differences in inhibitory responses are not explained by somatic synapse density.
Area of Science:
- Neuroscience
- Cell Biology
- Computational Biology
Background:
- Pyramidal neurons exhibit distinct firing patterns (regular spiking/RS and intrinsically bursting/IB).
- RS and IB neurons show differences in membrane properties and morphology.
- RS cells typically display inhibitory postsynaptic potentials, unlike most IB cells.
Purpose of the Study:
- To investigate if differing inhibitory responses in RS vs. IB neurons correlate with distinct inhibitory synapse concentrations on their somata.
- To test the hypothesis that pyramidal cell types have characteristic synaptic patterns.
Main Methods:
- Developed an advanced electron microscopic-video-computer system for 3D neuronal reconstructions and synaptic analysis.
- Identified and labeled RS and IB neurons in rat somatosensory cortex using intracellular recording.
- Examined serial thin sections with electron microscopy to map synapses onto somata and proximal dendrites.
- Created computer-assisted 3D reconstructions for quantitative synaptic analysis.
Main Results:
- No significant differences were found in the types or concentration of synapses on the somata and proximal dendrites of IB and RS neurons.
- The observed differences in inhibitory responses between RS and IB neurons are not attributable to somatic synapse density.
Conclusions:
- The distinct inhibitory responses of RS and IB neurons are not explained by the density of inhibitory synapses on their cell bodies.
- Quantitative analysis of synaptic organization has entered a new era of efficiency with advanced imaging and computational tools.