NROSCI 0081 Lecture Notes - Lecture 14: Limbic System, Deep Brain Stimulation, Opioid
Document Summary
Pain: unpleasant sensory or emotional experience associated with actual or potential tissue damage. Hyperalgesia increased sensitivity to pain following an injury. Allodynia a normally non-painful stimulus becomes painful after an injury. Nociception: encoding and processing of painful stimuli: done by central and peripheral nervous systems, sensation of pain. C not myelinated, throbbing, chronic pain. Ascending pain pathway: nociceptors dorsal horn of spinal cord spinothalamic tract. Descending pain pathway inhibitory input: primary somatosensory cortex/amygdala (limbic system) hypothalamus periaqueductal gray (opioids, turns down pain, deep brain stimulation) raphe nucleus (medulla) dorsal horn of spinal cord. At that synapse, it inhibits the neuron from sending more pain activation back up. Opioid receptors: activated by endogenous opioids and external opiates. Endogenous endorphins, dynorphins, enkephalins: inhibit neurotransmission inhibits calcium channels, activate potassium in postsynaptic side, opioids can affect pain . Pag activation increases the descending pain pathway.
