Axon Diversity of Lamina I Local-Circuit Neurons in the Lumbar Spinal Cord

Autor: Paulo Aguiar, Raquel Ramos Pinho, Sheena Y.X. Tiong, Zsófia Antal, Boris V. Safronov, Liliana L. Luz, Peter Szucs, Andrew J. Todd
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Lamina
Patch-Clamp Techniques
Interneuron
Nerve net
propriospinal connection
Vesicular Inhibitory Amino Acid Transport Proteins
Models
Neurological
Action Potentials
interneuron
Biology
propagation time
In Vitro Techniques
Inhibitory postsynaptic potential
03 medical and health sciences
0302 clinical medicine
Imaging
Three-Dimensional
3-D reconstruction
Microscopy
Electron
Transmission
medicine
Animals
Axon
Rats
Wistar
Research Articles
030304 developmental biology
Neurons
0303 health sciences
Neurotransmitter Agents
General Neuroscience
Lysine
Anatomy
Dendrites
Spinal cord
Axons
varicosity distribution
Rats
Lumbar Spinal Cord
medicine.anatomical_structure
Nociception
nervous system
Animals
Newborn
Spinal Cord
Vesicular Glutamate Transport Protein 2
Nerve Net
Neuroscience
030217 neurology & neurosurgery
Zdroj: The Journal of Comparative Neurology
ISSN: 1096-9861
0021-9967
Popis: Spinal lamina I is a key area for relaying and integrating information from nociceptive primary afferents with various other sources of inputs. Although lamina I projection neurons have been intensively studied, much less attention has been given to local-circuit neurons (LCNs), which form the majority of the lamina I neuronal population. In this work the infrared light-emitting diode oblique illumination technique was used to visualize and label LCNs, allowing reconstruction and analysis of their dendritic and extensive axonal trees. We show that the majority of lamina I neurons with locally branching axons fall into the multipolar (with ventrally protruding dendrites) and flattened (dendrites limited to lamina I) somatodendritic categories. Analysis of their axons revealed that the initial myelinated part gives rise to several unmyelinated small-diameter branches that have a high number of densely packed, large varicosities and an extensive rostrocaudal (two or three segments), mediolateral, and dorsoventral (reaching laminae III–IV) distribution. The extent of the axon and the occasional presence of long, solitary branches suggest that LCNs may also form short and long propriospinal connections. We also found that the distribution of axon varicosities and terminal field locations show substantial heterogeneity and that a substantial portion of LCNs is inhibitory. Our observations indicate that LCNs of lamina I form intersegmental as well as interlaminar connections and may govern large numbers of neurons, providing anatomical substrate for rostrocaudal “processing units” in the dorsal horn. J. Comp. Neurol. 521:2719–2741, 2013.
Databáze: OpenAIRE
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