Pain is a complex and generally unpleasant experience that serves the important protective function of alerting us to situations that may threaten our well being. As such, pain is typically associated with noxious stimuli. Pain processing begins with specialized sensory neurons, called nociceptors, that are able to distinguish and preferentially respond to noxious stimuli.  Nociceptive primary afferent neurons receive information via free nerve endings at their peripheral terminals and pass that information to second order neurons in the dorsal horn of the spinal cord. The first synapse in the pain pathway is one of the most targeted sites for analgesic drugs. From here, several ascending pathways exist to relay messages related to arousal as well as affective and other aspects of pain.

This eBook covers the various pain processing pathways, common drug classes and choosing the suitable pain behaviors for efficacy testing:

• Cannabinoid Receptor anagonists
• FAAH inhibition
• Opioids
• α2-adrenergic agonists
• Tricyclic anti-depressants
• NSAIDs
• Cation Channel Blockers (Na+, Ca+, TRPV1)