The zonal layer (also known as the stratum zonale or layer 1) represents the most superficial layer of the superior colliculus (SC), a paired midbrain structure critical for orienting behaviors and multisensory integration. Located dorsally above the intermediate and deep layers, the zonal layer receives direct input from the retina and visual cortex, playing a fundamental role in visual processing and the initiation of orienting responses. This page provides comprehensive information about the structure, function, cellular composition, and role of zonal layer neurons in neurodegenerative diseases. [1]
| Property | Value | [2]
|----------|-------| [3]
| Category | Midbrain | [4]
| Location | Superior colliculus, superficial layer (layer 1) | [5]
| Cell Types | Vertical cells, horizontal cells, marginal cells, pyriform neurons | [6]
| Primary Neurotransmitter | GABA (inhibitory), Glutamate (excitatory) | [7]
| Key Markers | Calbindin D-28k (CaBP), Parvalbumin, Calretinin, Neurofilament proteins | [8]
| Input Sources | Retina, visual cortex (V1, V2), pretectal area | [9]
| Output Targets | Intermediate layers, deep layers, thalamus (pulvinar) | [10]
The superior colliculus consists of seven distinct laminae, with the zonal layer (stratum zonale) comprising the most superficial tier. This thin but architecturally distinct layer sits atop the superficial gray layer (stratum griseum superficiale) and extends approximately 100-150 μm in depth in primates [1]. [11]
Vertical Cells (Tectal Columnar Neurons) [12]
Horizontal Cells (Tangential Neurons) [13]
Marginal Cells [14]
Pyriform Neurons [15]
Retinal Ganglion Cell Input [16]
Cortical Visual Input [17]
Pretectal Input [18]
Intralaminar Projections [19]
Thalamic Projections [20]
Spatial Organization [21]
Latency [22]
The zonal layer serves as a critical node in transforming visual coordinates into motor commands: [23]
Saccadic Abnormalities [24]
Eye Movement Deficits [25]
Mechanistic Basis [26]
Vertical Gaze Palsy [27]
Oculomotor Dysfunction [28]
Neuropathology [29]
Visual Processing Deficits [30]
Anatomical Connections [31]
Potential Mechanisms [32]
Saccadic Dysfunction
Oculomotor Findings
Eye Tracking
Neuroimaging
Superior Colliculus as Target
Subthalamic Nucleus/Globus Pallidus Stimulation
Dopaminergic Medications
Cholinergic Agents
The study of Zonal Layer Superior Colliculus Neurons has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
May PJ. The mammalian superior colliculus: laminar structure and connections. Prog Brain Res. 2006;151:321-351. 2006. ↩︎
Munoz DP, Wurtz RH. Saccade-related activity in monkey superior colliculus. I. Temporal and spatial displacement. J Neurophysiol. 1995;73(6):2424-2447. 1995. ↩︎
Mize RR, Spencer RF. Comparative patterns of synaptic organization in the primate superficial superior colliculus. Prog Brain Res. 2006;151:367-395. 2006. ↩︎
Huberman AD, Niell CM. What can mice tell us about visual function in the superior colliculus? Learn Mem. 2011;18(5):298-306. 2011. ↩︎
Stein BE, Stanford TR. Multisensory integration: current issues from the perspective of the single neuron. Nat Rev Neurosci. 2008;9(4):255-266. 2008. ↩︎
Fitousi D. On the internal organization of the primate superior colliculus. Front Neuroanat. 2015;9:84. 2015. ↩︎
Cave C, Sharpe J. Corticocollicular projections to the superior colliculus in the mouse. Brain Struct Funct. 2021;226(8):2569-2585. 2021. ↩︎
Gamlin PD. The pretectum: connections and oculomotor-related roles. Prog Brain Res. 2006;151:379-405. 2006. ↩︎
Isa T, Sasaki S. Brainstem control of head movements during orienting: organization of the premotor circuitry. Curr Opin Neurobiol. 2002;12(6):633-638. 2002. ↩︎
Baldauf Z, Chomsung RD, Card JP, May PJ. Ultrastructural analysis of projections to the pulvinar nucleus of the cat. Exp Brain Res. 2005;162(3):304-312. 2005. ↩︎
Goldberg ME, Wurtz RH. Activity of superior colliculus in behaving monkey. I. Visual receptive fields of single neurons. J Neurophysiol. 1972;35(4):542-559. 1972. ↩︎
Sommer MA, Wurtz RH. A pathway in primate brain for internal monitoring of movements. Science. 2002;296(5572):1480-1482. 2002. ↩︎
Sparks DL. The functional organization of the primate superior colliculus. Annu Rev Neurosci. 1986;9:265-289. 1986. ↩︎
Terao Y, Fukuda H, Yugeta A, et al. Initiation and inhibitory control of saccades with the progression of Parkinson's disease. Brain. 2011;134(Pt 7):2089-2105. 2011. ↩︎
Pinkhardt EH, Jürgens R, Becker W, Valdarno F, Ludolph AC, Kassubek J. Saccadic impairment in Parkinson's disease: evaluation of characteristic patterns with standardized eye movement assessment. Clin Neurophysiol. 2013;124(4):700-708. 2013. ↩︎
Basso MA, Liu P. Complex questions about the function of the basal ganglia and the superior colliculus. J Neuroophthalmol. 2007;27(1):49-55. 2007. ↩︎
Bhattacharya K, Sae-Tell ST, Margolin E. The "downgaze" sign. CMAJ. 2012;184(2):197. 2012. ↩︎
Roh TG, Kang H, Lee BH, Kim HY, Sohn YH. Progression of vertical saccadic impairment in atypical parkinsonism. J Neurol Sci. 2020;415:116920. 2020. ↩︎
Dickson DW, Bergeron C, Haines A, et al. Neuropathologic variation in progressive supranuclear palsy. Acta Neuropathol. 2013;126(3):415-425. 2013. ↩︎
Tychsen L, Lisberger SG. Visual motion processing in the primate. J Clin Neurol. 2019;15(2):87-106. 2019. ↩︎
Chee MW, Rugg MD. Functional neuroimaging of memory in aging and Alzheimer's disease. Ann N Y Acad Sci. 2008;1144:3-13. 2008. ↩︎
Shadowska M, Stawarski M, Wiaderkiewicz R. Cholinergic mechanisms in the superior colliculus and their role in visual attention. Neurobiology (Bucur). 2018;26(1):1-15. 2018. ↩︎
Blekher T, Johnson SA, Marshall J, et al. Saccades in presymptomatic and early stages of Huntington disease. Neurology. 2006;67(3):394-399. 2006. ↩︎
Kim JS, Park JW, Heo WY, Kwon DY. Oculomotor dysfunction in multiple system atrophy. J Neurol Sci. 2008;271(1-2):83-89. 2008. ↩︎
Leigh RJ, Kennard C. Using saccades as a research tool in the clinical neurosciences. Brain. 2004;127(Pt 3):460-477. 2004. ↩︎
Filippi M, Agosta F. Neuroimaging of atypical parkinsonisms. Mov Disord. 2014;29(5):593-604. 2014. ↩︎
Nandi D, Aziz T, Carter H, Stein J. Deep brain stimulation of the pedunculopontine region: an emerging therapy for gait disorders. J Neurol Neurosurg Psychiatry. 2012;83(9):843-852. 2012. ↩︎
Fukuda H, Terao Y, Hikosaka O. Effects of subthalamic nucleus stimulation on saccade in Parkinson's disease. Brain. 2003;126(8):1739-1754. 2003. ↩︎
Hikosaka O, Wurtz RH. Effects of dopamine on saccadic eye movements. Prog Brain Res. 2011;183:199-210. 2011. ↩︎
Bezdicek O, Nikolai M, Stepankova H, et al. Effects of cholinesterase inhibitors on visual attention in Alzheimer's disease. J Alzheimers Dis. 2015;45(2):489-500. 2015. ↩︎
Keller EL, McPeek RM, Szatlocz E. Neural coding in the primate superior colliculus. Prog Brain Res. 2008;171:89-95. 2008. ↩︎
Gandhi CC, Katare B, Sahin B. Molecular characterization of the superior colliculus. Front Neuroanat. 2020;14:56. 2020. ↩︎