Spinal nerves

The intrathecal space is located between the arachnoid and the pia mater of the spinal cord. It contains the cerebrospinal fluid, spinal nerves and blood vessels. 

AM1241 (360) exhibited high affinity and selectivity for CB2 [it (CBi) = 280 nM, (CB2) = 3.4 nM]. (360) Dose dependently inhibited experimental neuropathic pain in a spinal nerve ligation-induced tactile and thermal hypersensitivity model [224]. Other indole derivatives bearing sulfonamide moieties on the side chain, such as compound (361), were disclosed [225]. Though 67 derivatives including pyridyl and other heteroaromatics instead of the indole core were listed, no specific biological data were shown. 

Polyradiculitis Refers to inflammation of multiple spinal nerve roots. 

The central nervous system (CNS) consists of the brain and spinal cord. The peripheral nervous system (PNS) consists of 12 pairs of cranial nerves that arise from the brainstem and 31 pairs of spinal nerves arising from the spinal cord. These peripheral nerves carry information between the CNS and the tissues of the body. The PNS consists of two divisions ... 

The spinal nerves associate with the spinal cord by way of two branches, or roots ... 

GRAY MATTER WHITE MATTER SPINAL NERVES... 

Figure 7.1 Cross-sectional view of the spinal cord. In contrast to the brain, the gray matter of the spinal cord is located internally, surrounded by the white matter. The gray matter consists of nerve cell bodies and unmyelinated intemeuron fibers. This component of the spinal cord is divided into three regions the dorsal, lateral, and ventral horns. The white matter consists of bundles of myelinated axons of neurons, or tracts. Each segment of the spinal cord gives rise to a pair of spinal nerves containing afferent and efferent neurons. Afferent neurons enter the spinal cord through the dorsal root and efferent neurons exit it through the ventral root.

The cell bodies of somatic motor neurons are found in the ventral horn. The axons of these neurons exit the CNS through the ventral root of the spinal nerve and innervate skeletal muscles. The two types of motor neurons located in the ventral horn are ... 

Interneurons are found in all areas of the spinal cord gray matter. These neurons are quite numerous, small, and highly excitable they have many interconnections. They receive input from higher levels of the CNS as well as from sensory neurons entering the CNS through the spinal nerves. Many intemeurons in the spinal cord synapse with motor neurons in the ventral hom. These interconnections are responsible for the integrative functions of the spinal cord including reflexes. 

The primary site of action of epidurally administered agents is on the spinal nerve roots. As with spinal anesthesia, the choice of drug to be used is determined primarily by the duration of anesthesia desired. However, when a catheter has been placed, short-acting drugs can be administered repeatedly. Bupivacaine is typically used when a long duration of surgical block is needed. Lidocaine is used most often for intermediate length procedures chloroprocaine is used when only a very short duration of anesthesia is required. 

Other nerve structures are also subject to variation. The position in the vertebral column at which the spinal cord terminates varies over three full vertebrae, and no standard terminal position exists. The positions at which various nerves enter the spinal cord likewise vary from individual to individual. About 15 per cent of the population do not have a "direct pyramidal" nerve tract in the spinal cord. Most human beings have 31 pairs of spinal nerves corresponding to 30 vertebrae some, however, have 32 and some 33 pairs, corresponding to 31 and 32 vertebrae, respectively. Most people have two splanchnic nerves (sympathetic nerves to the digestive system), but occasional individuals have three. In some individuals the sciatic nerve is so embedded that it is always fully protected in others, the pathway of the nerve is such that injury is very likely to occur. 

Spinal anesthesia Spinal anesthesia is the introduction of local anesthetics directly into the spinal fluid, which causes a sympathetic blockage, or loss of feeling as well as muscle relaxation resulting from the interaction of anesthetic with every spinal nerve tract. This method is used during major surgical interventions. As a rule, lidocaine, mepivacaine, and bupivacaine are used for this purpose. 

Motor activity changes were also observed in rats administered doses of FireMaster FF-1 as low as 1 mg/kg/day for 4 weeks (Geller et al. 1979). In this experiment, neither learning nor performance of a simple discrimination task was affected by 1, 3, or 6 mg/kg/day dosage levels, but increased motor activity was observed at 1 mg/kg/day. No changes were apparent at 3 mg/kg/day and decreased motor activity was apparent at 6 mg/kg/day, compared with controls. Weakness of the hind limb was noted in rats treated with 10 mg/kg/day FireMaster FF-1 for 6 months compared with control rats (Cabe and Tilson 1978). Histological examination of brain and/or spinal nerve tissue found no FireMaster FF-l-related alterations in rats or mice administered up to 10 mg/kg/day for 25 weeks (NTP 1983) or 3.9 mg/kg/day for up to 105 weeks (NTP 1992). 

Kim, S. H. and Chung, J. M. An experimental model for peripheral neuropathy produced by segmental spinal nerve ligation in the rat, Pain 1992, 50, 355-363. 

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