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Non-Synonyms (Similar-Sounding)
Published in Terence R. Anthoney, Neuroanatomy and the Neurologic Exam, 2017
Pretectal area (B&K, p. 110): An area in the rostralmost superior colliculus, near the posterior commissure, containing one or more nuclei. As a group, these nuclei may be called the pretectal nuclei: some have formal names that include the word “pretectal,” but others do not (see below).
Neurological Examination
Published in Walter J. Hendelman, Peter Humphreys, Christopher R. Skinner, The Integrated Nervous System, 2017
Walter J. Hendelman, Peter Humphreys, Christopher R. Skinner
Pathway (Figure 2.2): The visual image, light in this case, is carried from the retina into the optic nerve; after the partial crossing of fibers in the optic chiasm, the stimulus is carried in the optic tract. Some of these fibers leave the optic tract and go to the dorsal area of the midbrain, in the pretectal area, where they terminate in a group of cells called the light reflex centre; the information is relayed immediately to the same group of neurons on the other side.
Impact of Retinal Stimulation on Neuromodulation
Published in Yu Chen, Babak Kateb, Neurophotonics and Brain Mapping, 2017
The subcortical superior colliculus also is involved in spatial attention (Schneider and Kastner 2009). Studies have shown that the superior colliculus/pretectal area and the visual cortical areas are each affected by changes in light (Miller et al. 1998). The superior colliculus pathway is independent of the classic cone pathway of seeing (Leh et al. 2010). Yet, the superior colliculus is still responsive to colors (Zhang et al. 2015). Sensory systems interact with the basal ganglia (Prescott et al. 2006). A clinical trial demonstrated that patients given placebo glasses were not as effectively treated as those prescribed actual glasses with prisms (Bowers et al. 2014). In other words, varying the dispersion of light onto the retina affected the patients’ reactions. New research shows that prism glasses altering the “Where is it?” pathway by shifting apparent target location also have an effect on the “How am I?” chemical pathway.
Per1 mutation enhances masking responses in mice
Published in Chronobiology International, 2022
Nemanja Milićević, Arthur A. Bergen, Marie-Paule Felder-Schmittbuhl
Masking responses are mediated by classical photoreceptor input involving rods and cones (Thompson et al. 2008) and melanopsin (Opn4) positive, intrinsically photosensitive retinal ganglion cells (ipRGCs)(Mrosovsky and Hattar 2003). IpRGCs project to the central clock in suprachiasmatic nuclei (SCN) and to other brain areas via retinal projections, including the retinohypothalamic tract (RHT) (Berson et al. 2002). The RTH projections are necessary for masking responses (Li et al. 2005), but the role of the SCN is still debated (Li et al. 2005; Redlin and Mrosovsky 1999). Other brain regions modulate masking responses such as the dorsal lateral geniculate nucleus (Edelstein and Mrosovsky 2001), the visual cortex (Redlin et al. 2003) and the intergeniculate leaflet (Langel et al. 2014; Redlin et al. 1999) among others. The circadian system can, in turn, modulate masking responses in both diurnal and nocturnal species (Shuboni et al. 2012; Smale et al. 2003). The neural underpinnings of this link are not well understood, but extensive work on the Nile grass rat revealed that many brain regions play important roles, such as: the ventral subparaventricular zone (Gall et al. 2016), the olivary pretectal area (Gall et al. 2017; Langel et al. 2014), the superior colliculus (Gall et al. 2020), among others (reviewed in detail by (Yan et al. 2020)).
Amplitude of Accommodation in Patients with Multiple Sclerosis
Published in Current Eye Research, 2019
Bekir Küçük, Mehmet Hamamcı, Seray Aslan Bayhan, Hasan Ali Bayhan, Levent Ertuğrul Inan
When the target distance is changed, the lens power must be altered to clearly view it; this is known as ocular accommodation.25 The accommodation reflex starts in the retinal ganglion cells with the light reflex. These impulses are sent through the optic nerve, the optic chiasma, and the optic tract. Most optic tract fibers go to the pretectal area, although some fibers synapse with the second-order neurons in the lateral geniculate nucleus of the thalamus. Then, second-order neurons carry the impulses through the optic radiation to the visual cortex. Impulses pass from the visual cortex to the prefrontal cortex, and fibers pass through the internal capsule to reach the midbrain. Then, the fibers in the midbrain synapse with the oculomotor nucleus and the Edinger-Westphal nucleus.26 The motor fibers are carried by the oculomotor nerve from the oculomotor nucleus to the medial rectus muscle, where both eyes converge. The efferent fibers of the Edinger-Westphal nucleus (which is the parasympathetic autonomic nucleus) accompany the oculomotor nerve and synapse in the ciliary ganglion. Then, the postganglionic fibers of the ciliary ganglion pass the short ciliary nerves to supply the sphincter pupillae muscle and the ciliary muscle, which allows the lens to thicken27 (Figure 1). This mechanism is controlled by the autonomic nervous system.23