Spinal cord Anatomical divisions Regionally elevated protein expression in human Regionally elevated protein expression in pig

Spinal cord

Summary

The spinal cord is part of the central nervous system that extends from the medulla oblongate. It is situated inside the vertebral canal and is the major link between body and brain. The spinal cord controls movement, processes sensory information like touch, vibration or presure (mechanoreception), temperature (thermoception), postion of lims (proprioception) and pain (nociception) but also controls autonomous functions like blood pressure, heart rate, body temperature and bodily functions like breathing, bladder control and bowel movements.

The transcriptome analysis shows that 67% (n=13529) of all human protein-coding genes (n=20090) are expressed in the human spinal cord grey matter, and that 13109 of all pig orthologues (n=15829) are expressed in the pig spinal cord.

Figure 1. Schematic drawing of the human brain, indicating the location of spinal cord from a sagittal perspective.

Anatomical divisions

The spinal cord extends from the medulla oblongate and is situated inside the vertebral canal. Based on the corresponding vertebrae level spinal cord is divided into the cervical (C1-8), thoracic (T1-12), lumbar (L1-5) and sacral (S1-5) segments. Spinal cord grey matter can be divided in dorsal horn, central grey and ventral horn. The dorsal horn comprises of sensory nuclei that process somatosensory input from sensory neurons. Motor neurons innervating skeletal muscles are located in the ventral horn. The intermediate column also containing the central grey is involved in controlling autonomic motor functions. The spinal cord white matter is divided in three tracts, the dorsal funiculus, lateral funiculus and anterior funiculus. The dorsal funiculs, also known as posterior funiculus, contains mainly ascending sensory fibers. The lateral and anterior funiculi contain ascending sensory fibers (spinothalamic tract) and descending motor fibers (corticospinal tract).

Regionally elevated protein expression in human

Table 1: Number of genes within the different categories of regionally elevated expression, in human spinal cord.

Specificity	Number of Human elevated genes
Region enriched	4
Group enriched	21
Region enhanced	10
Elevated	35

Table 2. The 4 genes with the highest level of enriched expression in human white matter. "Predicted localization" shows the classification of each gene into three main classes: Secreted, Membrane, and Intracellular, where the latter consists of genes without any predicted membrane and secreted features. RS-score (Regional Specificity score) corresponds to the score calculated as the fold change to the second highest region.

Gene	Description	Predicted location	RS-score
IGKJ3	Immunoglobulin kappa joining 3	Intracellular	12
IGKV3-11	Immunoglobulin kappa variable 3-11	Secreted	9
IGKV1-33	Immunoglobulin kappa variable 1-33	Intracellular,Secreted	7
IGHV4-28	Immunoglobulin heavy variable 4-28	Secreted	5

Regionally elevated protein expression in pig

Table 3: The 89 of genes within the different categories of regionally elevated expression, in pig spinal cord.

Specificity	Number of Pig elevated genes
Region enriched	89
Group enriched	45
Region enhanced	80
Elevated	214