The central tegmental tract contains descending and ascending fibers. It runs from the
red nucleus to the inferior
olivary nucleus. In humans it is very small and runs ventral to the
lateral corticospinal tract. The inferior olivary nucleus projects to the contralateral
cerebellum via
olivocerebellar fibers. The rubro-olivary fibres descend through the
superior cerebellar peduncle.
Ascending fibers Ascending fibers are
second-order axons projecting from the
gustatory nucleus (the rostral part of the
solitary nucleus] to the
ventral posteromedial nucleus of
thalamus (
third-order neurons in turn project to the
gustatory cortex). Ascending reticulothalamic fibres project from the medial zone nuclei of the
reticular formation to the
hypothalamus (to mediate autonomic nervous system response), and the
intralaminar thalamic nuclei (to mediate a startle response to pain). == Clinical significance ==