Ganglion cranial

The peripheral sensory neurons that supply the chemoreceptors in the oral cavity reside in four distinct cranial ganglia (Figure 4). The trigeminal ganglion contains the sensory... 

The cell bodies of parasympathetic preganglionic neurons are located in the brainstem and the sacral spinal cord. Parasympathetic outflow is channeled from the brainstem (1) through the third cranial nerve (oculomotor n.) via the ciliary ganglion to the eye (2) through the seventh cranial nerve (facial n.) via the pterygopalatine and submaxillary... 

Figure 1. Diagram of the three cranial nerves and associated sensory ganglia that innervate taste buds. As illustrated, electrical recordings were taken from single neurons in the ganglia. Geniculate ganglion in facial nerve petrosal in glossopharyngeal nodose in vagus.

A switch in neurotrophin requirements has been found for neurons which depend only on NGF for survival (sympathetic, dorsomedial trigeminal, jugular, some DRG cells Buj-Bello et al. (1994)). A wide range of these neurons show a switch from a transient early dependence on NT-3 and/or BDNF to a later dependence on NGF (for a review see Davies, 1994). For instance, up until ElO, survival of trigeminal ganglion neurons is dependent on BDNF and/or NT-3 later, when naturally programmed cell death takes place (E13-E18) these neurons require only NGF (Buchman and Davies, 1993). Similarly, the survival of NGF-dependent, but not BDNF-dependent, cranial sensory neurons is promoted by different neurotrophins early in their development (Buj-Bello et al.,... 

The parasynqtathetic system is also known as the craniosacral portion of the autonomic nervous system because of the sites of origin of the pre-ganglionic fibers. The cranial portion has ganglia associated with the third, seventh, ninth, and tenth cranial nerves. Spinal cord segments S2, S3, and S4 comprise the sacral portion. 

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