Is the vestibular ganglia located in the CNS or PNS?

Question

Is the vestibular ganglia located in the CNS or in the PNS?
Today in my nervous systems class we were talking about the cranial nerves. My professor said that only ANS nerves have ganglia in the PNS, and all sensory and somatic motor nerves synapse within the CNS. When we were looking at the vestibulcochlear nerve (cranial nerve 9) I noticed in the diagram the vestibular ganglia appeared to be in the PNS, but since this is a sensory only nerve, the ganglia should be in the CNS. I asked my professor about it after class, and he said it was a good question and that I should research it. I was wondering if anyone here has taken a neurobiology class and can help me out. Thanks in advance.

Answer 1

Your professor is correct in that the nerves of the autonomic N/S do have ganglia in the PNS, but a cranial nerve with sensory afferents will have a ganglia in the CNS like CN-7 utilizes the Geniculate ganglion for the cell bodies of its primary sensory function. The vestibularcochlear nerve is CN-8. This is actually 2 nerves the vestibular nerve and the cochlear nerve. The cochlear nerve consists principally of axons of cells in the Spiral Ganglion. The spiral ganglion is indeed in the CNS. Your professor is incorrect in that nerves of the ANS are the only ones that have ganglia in the PNS. The sensory nerves of the body are of the pseudounipolar neurons that have the cell bodies in the Dorsal Root Ganglia, located just next to the spinal column. These ganglia contain the cell bodies for the body sensory nerves. I hope this helps and now you can correct your professor about the Dorsal root ganglia in the pns.

Answer 2

Vestibular Ganglia

Answer 3

Mr. Answerman is spot on!