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With depression affecting around 1 in 10 of us at some point during our lives, the need for new and improved treatments is a top priority for researchers – and it appears that spinal cord stimulation could be one route for experts to investigate.
A team led by researchers at the University of Cincinnati College of Medicine devised a pilot clinical trial in which a little black box was placed on the spinal cord of 20 volunteers with depression, with one electrode on the back and one on the right shoulder..Story continues…
By: DAVID NIELD
Source: Marketing Scoops: The Spinal Cord Could Provide a Radical New Way To Treat Depression
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Critics:
The spinal cord proper terminates in a region called the conus medullaris, while the pia mater continues as an extension called the filum terminale, which anchors the spinal cord to the coccyx. The cauda equina (“horse’s tail”) is a collection of nerves inferior to the conus medullaris that continue to travel through the vertebral column to the coccyx.
The cauda equina forms because the spinal cord stops growing in length at about age four, even though the vertebral column continues to lengthen until adulthood. This results in sacral spinal nerves originating in the upper lumbar region. For that reason, the spinal cord occupies only two-thirds of the vertebral canal. The inferior part of the vertebral canal is filled with cerebrospinal fluid and the space is called the lumbar cistern.
Within the central nervous system (CNS), nerve cell bodies are generally organized into functional clusters, called nuclei. Axons within the CNS are grouped into tracts. The spinal cord is made from part of the neural tube during development. There are four stages of the spinal cord that arises from the neural tube: The neural plate, neural fold, neural tube, and the spinal cord.
Neural differentiation occurs within the spinal cord portion of the tube. As the neural tube begins to develop, the notochord begins to secrete a factor known as Sonic hedgehog (SHH). As a result, the floor plate then also begins to secrete SHH, and this will induce the basal plate to develop motor neurons. During the maturation of the neural tube, its lateral walls thicken and form a longitudinal groove called the sulcus limitans. This extends the length of the spinal cord into dorsal and ventral portions as well.
Meanwhile, the overlying ectoderm secretes bone morphogenetic protein (BMP). This induces the roof plate to begin to secrete BMP, which will induce the alar plate to develop sensory neurons. Opposing gradients of such morphogens as BMP and SHH form different domains of dividing cells along the dorsal ventral axis. Dorsal root ganglion neurons differentiate from neural crest progenitors.
As the dorsal and ventral column cells proliferate, the lumen of the neural tube narrows to form the small central canal of the spinal cord. The alar plate and the basal plate are separated by the sulcus limitans. Additionally, the floor plate also secretes netrins. The netrins act as chemoattractants to decussation of pain and temperature sensory neurons in the alar plate across the anterior white commissure, where they then ascend towards the thalamus.
Following the closure of the caudal neuropore and formation of the brain’s ventricles that contain the choroid plexus tissue, the central canal of the caudal spinal cord is filled with cerebrospinal fluid. Earlier findings by Viktor Hamburger and Rita Levi-Montalcini in the chick embryo have been confirmed by more recent studies which have demonstrated that the elimination of neuronal cells by programmed cell death is necessary for the correct assembly of the nervous system.
Overall, spontaneous embryonic activity has been shown to play a role in neuron and muscle development but is probably not involved in the initial formation of connections between spinal neurons. The human spinal cord is divided into segments where pairs of spinal nerves (mixed; sensory and motor) form. Six to eight motor nerve rootlets branch out of right and left ventralateral sulci in a very orderly manner.
Nerve rootlets combine to form nerve roots. Likewise, sensory nerve rootlets form off right and left dorsal lateral sulci and form sensory nerve roots. The ventral (motor) and dorsal (sensory) roots combine to form spinal nerves (mixed; motor and sensory), one on each side of the spinal cord. Spinal nerves, with the exception of C1 and C2, form inside the intervertebral foramen. These rootlets form the demarcation between the central and peripheral nervous systems.
Generally, the spinal cord segments do not correspond to bony vertebra levels. As the spinal cord terminates at the L1-L2 level, other segments of the spinal cord would be positioned superior to their corresponding bony vertebral body. For example, the T11 spinal segment is located higher than the T11 bony vertebra, and the sacral spinal cord segment is higher than the L1 vertebral body.
The grey column, (as three regions of grey columns) in the center of the cord, is shaped like a butterfly and consists of cell bodies of interneurons, motor neurons, neuroglia cells and unmyelinated axons. The anterior and posterior grey column present as projections of the grey matter and are also known as the horns of the spinal cord. Together, the grey columns and the grey commissure form the “grey H.”
The white matter is located outside of the grey matter and consists almost totally of myelinated motor and sensory axons. “Columns” of white matter carry information either up or down the spinal cord. The spinal cord proper terminates in a region called the conus medullaris, while the pia mater continues as an extension called the filum terminale, which anchors the spinal cord to the coccyx.
The cauda equina (“horse’s tail”) is a collection of nerves inferior to the conus medullaris that continue to travel through the vertebral column to the coccyx. The cauda equina forms because the spinal cord stops growing in length at about age four, even though the vertebral column continues to lengthen until adulthood. This results in sacral spinal nerves originating in the upper lumbar region.
For that reason, the spinal cord occupies only two-thirds of the vertebral canal. The inferior part of the vertebral canal is filled with cerebrospinal fluid and the space is called the lumbar cistern.
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