After the brain was exposed, the left superficial layer of the superior colliculus (sSC) and the central nucleus of the inferior
colliculi (ICc) on both sides were cauterized.
One recent study showed decreased connectivity between the inferior
colliculi and the auditory cortices [17].
The brains displayed a pattern of vacuolation characterized by intense spongiosis with many confluent vacuoles in the basal telencephalon (septum, striatum, caudate putamen nuclei), midbrain (thalamus, hypothalamus), mesencephalon (
colliculi), and in some parts of the brainstem (tegmental ventral area, raphe nuclei).
Visual inspection of these brains confirmed that the volume of cerebral cortex was reduced dramatically by a dose of 25 mg/kg, as indicated by the exposed dorsal surface of both inferior and superior
colliculi (Figure 1).
Classically in Wernicke encephalopathy prominent involvement of inferior
colliculi and periaqueductal area are seen in diffusion weighted images(DWI).
However, in sCJD-infected mice, vacuolar lesions were mostly observed in the anterior parts of the brain (except the parietal cortex), whereas in mice infected with lemur-passaged L-BSE, the lesions were more widely distributed, involving the
colliculi and the hypothalamus.
Because the cerebellum represents an inappreciable proportion of brain weight on GD21, the remainder was designated "brainstem." This dissection, which follows the natural planes of the fetal and neonatal rat brain, includes the corpus striatum, hippocampal formation, and neocortex within the area designated "forebrain." The region designated "brainstem" includes the midbrain,
colliculi, pons, and medulla oblongata (but not cervical spinal cord), as well as the thalamus.
Altered auditory inputs may support in tinnitus patients widespread functional reorganization of synaptic connections leading to dysfunctional activity in several subcortical lemniscal structures [36, 49, 53, 60-62, 67, 68, 78, 79] (cochlear nuclei, inferior
colliculi (IC), and medial geniculate bodies) and associative auditory cortex [67]; Cochlear nuclei (ventral and dorsal) have been found hyperactive [51, 52, 54, 55, 59, 61, 62], IC has been found reduced in volume [44] and both hyper and hypoactive [45,46,49] and Medial geniculate bodies have been found hypoactive in left sided tinnitus patients [49].
Perhaps the influence of directed attention is carried out through additional descending circuits of saccade initiation from the cortical frontal oculomotor fields to the brainstem saccadic generator, bypassing the superior
colliculi (Gaymard et al., 1998).
The abducens nuclei occupy a posterior position close to, but not at, the midline of the middle-to-caudal pons (Figure 5), separated from the floor of the 4th ventricle by axon fascicles of the main facial (7th cranial) nerves which bend around them forming paired posterior surface swellings at this pontine level (the facial
colliculi).
The function of the orientation network is to select sensory stimuli, and its activity is related to the posterior parietal cortex, the pulvinar nucleus of the thalamus and the superior
colliculi (Posner & Raichle, 1994).
They are thought to be caused by abnormal insertion of the mesonephric ducts into the cloaca in the place of the normal plicae
colliculi, which cause varying degrees of obstruction.