Stress-Response
Acute Stress Response: Analgesia
Purpose: to decrease the perception of pain
Two forms of stress-induced analgesia (SIA):
- opiate-dependent SIA: endogenous opiates (enkephalins and ?-endorphin) are released within the brain to inhibit the processing of sensory information associated with pain
- opiate-independent SIA: other neurotransmitters (e.g., glutamate) can also act to inhibit the processing of painful information; endogenous opiates are not involved in this process
- both forms of SIA would occur during a normal stress encounter
Adaptive nature of SIA: the zebra and the lion
- a lion attacks but does not kill a zebra; the zebra�s stomach is ripped open (stress response), yet for the next few hours, it has enough strength to evade the lion; a part of this response is the occurrence of SIA; if the zebra stopped to attend to it�s wound, it would most likely be killed by the lion; the decrease in perception of pain allows the zebra to continue to flee from the lion