| Pseudounipolar neuron | |
|---|---|
 1: Pseudounipolar neuron; 2:Bipolar neuron | |
 | |
| Details | |
| System | Nervous system |
| Identifiers | |
| Latin | neuron pseudounipolare |
| TH | H2.00.06.1.00047 |
| Anatomical terms of neuroanatomy | |
Apseudounipolar neuron is a type ofneuron which has one extension from its cell body. This type of neuron contains anaxon that has split into two branches. They developembryologically asbipolar in shape, and are thus termed pseudounipolar instead ofunipolar.[1]
A pseudounipolar neuron has oneaxon that projects from thecell body for relatively a very short distance, before splitting into two branches. Pseudounipolar neurons aresensory neurons that have nodendrites, the branched axon serving both functions.[2] The peripheral branch extends from the cell body to organs in the periphery including skin, joints and muscles, and the central branch extends from the cell body to thespinal cord.[3]
The cell body of a pseudounipolar neuron is located within adorsal root ganglion.[2] The axon leaves the cell body (and out of the dorsal root ganglion) into the dorsal root, where it splits into two branches. The central branch goes to thedorsal columns of the spinal cord, where it formssynapses with other neurons. The peripheral branch travels through the distaldorsal root into the spinal nerve all the way until skin, joint, and muscle.
Pseudounipolar neurons are found in the sensory ganglia of mostcranial nerves.
Specifically the:
Pseudounipolar neurons in cranial nerve sensory ganglia synapse in themain sensory trigeminal nucleus,spinal trigeminal nucleus orsolitary nucleus.
While thevestibulocochlear nerve has two ganglia associated with it (spiral ganglion andvestibular ganglion), both containbipolar neurons, not pseudounipolar.
The mesencephalic nucleus is made up of pseudounipolar neurons which migrated into thebrainstem during embryological development. It is the only location in thecentral nervous system where the cell bodies of pseudounipolar neurons are found.
All pseudounipolar neurons are sensory neurons. The ones found in the dorsal root ganglia, and majority of those in cranial nerve sensory ganglia carry information about touch, vibration, proprioception, pain and temperature.
Pseudounipolar neurons in the geniculate ganglion, inferior ganglion of theglossopharyngeal nerve and inferior ganglion of thevagus nerve also carry information about taste from taste buds.
Some of the pseudounipolar neurons in the inferior ganglion of the glossopharyngeal nerve carry information from thecarotid body andcarotid sinus.
The pseudounipolar neurons in themesencephalic nucleus carry proprioceptive information from themuscle of mastication.