Nervous system pain transmission

Analgesics interfere with the generation and/or transmission of impulses following noxious stimulation ( nociception) in the nervous system. This can occur at peripheral and/or central levels of the neuraxis. The therapeutic aim is to diminish the perception of pain. 

Endogenous opioid peptide released both in the central nervous system and in other apparatuses of the body that have many regulatory functions, including inhibition of pain transmission. 

The primary counterirritant in group D is capsaicin, a natural substance found in red chili peppers and responsible for the hot, spicy characteristic when used in foods.32,33,48 Capsaicin stimulates the release of substance P from local sensory nerve fibers, depleting substance P stores over time. A period of reduced sensitivity to painful stimuli follows, and transmission of pain impulses to the central nervous system is reduced.42... 

What is a synapse In the brain, the nerve cells or neurons are connected at special functional junctions called synapses, which depend on many proteins, including large complexes. They participate in basic functions with important roles in coordinating every characteristic of the nervous system, including physiology, emotions, learning, sleep, memory, and pain signal transmission. 

Binds to DNA and prevents separation of the helical strands Affects neuronal transmissions Binds to opiate receptors and blocks pain pathway Acts as central nervous system depressant Inhibits Na/K/ATPase, increases intracellular calcium, and increases ventricular contractibility Blocks the actions of histamine on Hi receptor Blocks ai-adrenergic receptor, resulting in decreased blood pressure Inhibits reuptake of 5-hydroxytryptamine (serotonin) into central nervous system neurons Inhibits cyclooxygenase, inhibition of inflammatory mediators Inhibits replication of viruses or tumor cells Inhibits HIV reverse transcriptase and DNA polymerase Antagonizes histamine effects... 

Pain, muscular weakness, cramps and ease of fatigue are the most usual symptoms of muscular disease. In most cases, it is diseases of the vascular or nervous system or problems with the processes providing energy within the muscle that are responsible for clinical problems with muscles. Other clinical problems include the muscular dystrophies, myotonic disorders, inflammatory myopathies and disorders of neuromuscular transmission (see Walton, 1996). The best known is Duchenne muscular dystrophy. 

One of the most promising helds of drug research is the search for chemical compounds that can relieve pain. Although the hiomo-lecular process by which pain is produced is not fully understood, scientists now have some important clues. One currently popular hypothesis ties the transmission of pain to a chemical compound known as substance P. Evidence suggests that substance P is a neurotransmitter that carries a "pain message from one neuron to an adjacent neuron. It may he responsible for the transmission of such messages from neurons in the peripheral nervous system to the brain. 

Substance P An eleven-amino add neurotransmitter that appears in both the central and peripheral nervous systems. It is involved in transmission of pain, causes rapid contractions of the gastrointestinal smooth muscle, and modulates inflammatory and immune responses. [NIH]... 

Methadone and opiates were first used for pain relief, and are still chiefly used in that area of medicine. It is important to remember that methadone and other opiates do not exert their pain control by altering a person s sensitivity to pain. Rather, methadone and other opiates interfere with the transmission of pain impulses from the nervous system to the brain. They accomplish this by a variety of methods. First, they decrease the transmission of nerve signals that conduct pain messages from various parts of the body to the spine. Secondly, they prevent production of neurochemicals that transfer this pain information to the spine. Finally, they mimic the actions of endorphins, which are the body s own pain-controlling chemicals. While methadone and other opiates work quite well to control pain, they do not affect touch, vision, or hearing. 

The ability to control pain and inflammation is an area of continued interest within the pharmaceutical industry. Sensoneuropeptide tachykinins, distributed in the peripheral and central nervous systems, are known to be involved in neurologic inflammation, pain transmission, and broncho-constriction.39 The activation of NK-1 (neurokinin-1), NK-2, and NK-3 receptors can mediate the effects of these tachykinins, resulting in a search for new antagonists as a means of controlling... 

Enkephalins are found in varying amounts in nearly all regions of the nervous system, in the posterior lobe of the pituitary, and in the adrenal cortex. They play a role in pain transmission in that they act as transmitters for the pain-inhibiting neurons in the spinal cord. 

Another endogenous peptide which has been implicated in pain transmission and the central integration of pain responses is neurotensin (NeT) (Dobner, 2006 Gui et al., 2004 Pettibone et al., 2002). NeT is a brain-gut tridecapeptide that fulfils a dual function as a neurotransmitter/neuromodulator in the nervous system, and as a paracrine and circulating hormone at the periphery. Three NeT receptors, NTRl,... 

Substance P is an 11-amino-acid peptide amide hormone discovered by von Euler and Gaddum in 1931 (43) from certain tissue extracts, especially from intestinal plain muscles and brains of horses. It is involved in the transmission of pain impulses from peripheral receptors to the central nervous system. It is also involved in the vomit reflex, stimulates salivary secretions, and induces vasodilation. Antagonists seem to have antidepressant properties. 

The nervous system consists of sensory and motor compo-nenLs. The. sensory compiment responds to various external stimulations, which it transmits in the form of a nerve impulse to the CNS for interpretation. The motor component of the nervous. system carries a signal from the CNS to the appropriate part of the bixly to elicit the rasponse to the stimulation. One of thc.se rcspoascs is the sensation known as pain. Nerve impulses arc now known to take the form of an electrical impulse. Experimental evidence suggests that both stimulation and the transmission of a nerve impulse may be bUx ked by the action of local anesthetic agents. Consequently, understanding this action requires a knowledge of the structure and action of the nervous system. 

Diethyl ether was the first general anesthetic used. The dentist Dr. William Morton is credited with its introduction in the 1800s. Diethyl ether functions as an anesthetic by interacting with the central nervous system. It appears that diethyl ether (and many other general anesthetics) functions by accumulating in the lipid material of the nerve cells, thereby interfering with nerve impulse transmission. This results in analgesia, a lessened perception of pain. 

The skeletal muscle ma5 be relaxed by two different groups of drugs, namely first, by those exerting an aetion on the central nervous system (CNS) and used mainly for the relief of painful muscle spasms of spasticity taking place either in neuromuseular or musculoskeletal disorders secondly, those aflfeeting neuromuscular transmission that are employed as adjrmcts in anaesthesia in order to modify the musele relaxation ability. 

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