Neurons involved in the sensory modality of orofacial pain from periphery to encephalon

Abstract

Introduction: Pain from the head and neck is linked to the trigeminal pathway and three neurons participate: a first-order neuron located in the trigeminal ganglion, a second-order neuron from the subnucleus caudalis of the trigeminal nerve, and a third-order neuron which starts from the medial area of the ventrobasal thalamus complex and ends in the cerebral cortex. Objective: Describe the way in which a chain of neurons transmit tissue damage to the encephalon by means of nerve impulses. Content: In first-order neurons, their neuronal bodies are located in the trigeminal spinal ganglion, in temporal bone. In the subnucleus caudalis, second-order neurons are found which receive nociceptive and temperature stimuli from the face and mouth. Their axons cross over the extension of this subnucleus, ascend contralaterally and establish synapses with third-order neurons in the thalamus. In the encephalon there is not a single "pain center": third-order neurons end in different areas of the cerebral cortex recognized as the "pain matrix". Final considerations: Three sets of neurons make up the trigeminal nociceptive pathway. The first one is located in the trigeminal ganglion outside the central nervous system whereas the other two form nuclei within it.

Keywords

• nocicepción
• canales iónicos de alto umbral
• nociceptores seudounipolares.