Antinociceptive system

Nociceptive system has a functional antipode - antinociceptive system, which controls the activity of the nociceptive system structures.

Antinociceptive system consists of a variety of nerve structures belonging to different departments and organizations CNS levels ranging from afferent inputs in the spinal cord and cerebral cortex ending. Each relay switch in the nociceptive system has its own control unit for the active constituent of nociceptive neurons.

Nociceptive and antinociceptive systems form a common system of pain sensitivity, which determines the nature of nociceptive signaling, measure its perception and the reaction to it.

Antinociceptive system plays an essential role in the mechanisms of prevention and elimination of pathological pain. Joining the reaction at nociceptive stimuli, it weakens the upward flow of nociceptive stimulation and the intensity of pain, so pain is under control and does not acquire pathological character. If any of the activities antinociceptive system nociceptive stimuli of small intensity even cause excessive pain. This effect takes place, for example, congenital or acquired deficiency antinociceptive mechanisms of the spinal cord, in particular when failure "gating control", in violation of the excitation by the thick fibers, activating this control, with injuries, infectious lesions of the central nervous system and so on.

In cases of failure antinociceptive system, it must be additional and special activation. The latter is carried out in various ways. Effective anti-nociceptive direct electrical stimulation of the brain structures that can cause suppression of even severe pathological pain. Many analgesics, including opioids endogenic peptides - endorphins, enkephalins exert their effect not only by a direct downward pressure on nociceptive neurons and blockade of excitatory synaptic transmission, but also via activation of antinociceptive system structures. Through activation of antinociceptive system function and non-pharmacological means of suppression of pain (eg, acupuncture). Electrical stimulation of thick fibers, activating "gating control" and other mechanisms of antinociceptive system, used clinically to suppress many kinds of pain, in particular peripheral origin.

However hyperactivation of antinociceptive system may lead to inadequate hypoalgesia and even profound suppression of pain sensitivity. These effects occur in the formation of structures in antinociceptive generator system. Hysterical loss of pain sensitivity, analgesia occurs in severe stress and some psychoses, it is also associated with increased activity of antinociceptive system.

CONTROL QUESTIONS

1. Mechanisms of brain Injury

2. Excitatory Amino Acid Injury

3. Increased intracranial pressure

4. Cerebral Edema

5. Hydrocephalus

6. Stroke, or “brain attack,”

7. The effects of traumatic head injuries

8. Cognitive disorders

9. Disorders of motor function

10. Disorders of peripheral nerves

11. Alterations in coordination of muscle movements