Related Experiment Video
Updated: Aug 8, 2026

Imaging Serotonergic Fibers in the Mouse Spinal Cord Using the CLARITY/CUBIC Technique
Published on: February 26, 2016
Less than 15% of the spinothalamic fibers originate from neurons in lamina I in cat
E M Klop1, L J Mouton, G Holstege
1Department of Anatomy and Embryology, Faculty of Medical Sciences, Rijksuniversiteit Groningen, Antonius Deusinglaan 1, bldg 3215, P.O. Box 196, 9700 AD Groningen, The Netherlands.
Abstract:
Lamina I neurons sending their axons into the spinothalamic tract are thought to play a crucial role in nociception, but many spinothalamic fibers do not originate from lamina I neurons. In cat, no consensus exists about what percentage of the spinothalamic tract cells are located in lamina I. After wheat germ agglutinin-conjugated horseradish peroxidase injections that covered large parts of the thalamus, retrogradely labeled cells were plotted and counted in all segments of the spinal cord. Results show that, averaged over all spinal segments, the percentage of labeled lamina I neurons was 4.9-14.2%. These results demonstrate that, in contrast to what is concluded in several previous studies, lamina I in the cat provides only a limited part of the total spinal input to the thalamus.
Related Concept Videos
The Spinal Cord
Spinal Cord: Cross-sectional Anatomy
Gray Matter and its Components
Central to the gray matter is...
Spinal Cord: Information Processing
Sensory Information Processing
Sensory information processing begins at the sensory receptors located in the skin and other tissues, which detect somatic sensory stimuli such as touch, temperature, or pain. These receptors function as catalysts, initiating...
Spinal Nerves: Anatomy
There are 31 bilateral pairs of spinal nerves, each emerging from the spinal cord through the intervertebral foramina—openings between adjacent vertebrae. These nerves are...
Overview of Somatic Sensory Pathways
The somatosensory system is divided into three main pathways: the dorsal (or posterior) column-medial lemniscus, spinothalamic (or anterolateral), and spinocerebellar pathways.
The dorsal...
Major Somatic Sensory Pathways

