PSYC 1200 Lecture Notes - Lecture 18: Periaqueductal Gray, Neuroglia, Microglia

• School: University of Manitoba
• Department: Psychology
• Course: PSYC 1200
• Professor: Dawson Clary

Document Summary

Cognitive and emotional processes that unfold in higher brain centres can block pain signals coming from peripheral receptors. Gate-control theory = incoming pain sensations must pass through a gate in the spinal cord that can be closed block ascending pain signals (not anatomic gate, patterns of neural activity no. Endorphins = natural, morphine-like painkillers, play important role in pain modulation. Descending neural path, mediates suppression of pain, originates in midbrain (periaqueductal grey = pag) Neural activity in path initiated by endorphins acting on pag neurons. Triggers impulses sent down neural circuits that release serotonin. Circuits = synapse in spinal cord, release more endorphins. Inhibits activity of neurons normally transmitting oncoming pain impulses to brain. 2 types of glial cells in spinal cord: astrocytes and microglia (play role in chronic pain), activated by immune system responses to infection or by signals from neurons in pain pathways.