Prior electrical stimulation of dorsal periaqueductal grey matter or deep layers of the superior colliculus sensitizes rats to anxiety-like behaviors in the elevated T-maze test

2006 ◽  
Vol 170 (2) ◽  
pp. 175-181 ◽  
Author(s):  
Leandro Pinto de Almeida ◽  
Patrício Lemos Ramos ◽  
José Eduardo Pandossio ◽  
Jesus Landeira-Fernandez ◽  
Hélio Zangrossi ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Superior Colliculus ◽  
Grey Matter ◽  
Periaqueductal Grey ◽  
Maze Test ◽  
Periaqueductal Grey Matter ◽  
Deep Layers ◽  
Stimulation Of

Topography of eye-position sensitivity of saccades evoked electrically from the cat's superior colliculus

1990 ◽  
Vol 4 (3) ◽  
pp. 289-298 ◽  
Author(s):  
James T. McIlwain
Keyword(s):  
Electrical Stimulation ◽  
Superior Colliculus ◽  
Vertical Component ◽  
Target Position ◽  
Eye Position ◽  
Starting Position ◽  
Position Sensitivity ◽  
Deep Layers ◽  
Stimulation Of ◽  
Retinotopic Map

AbstractSaccades evoked electrically from the deep layers of the superior colliculus have been examined in the alert cat with its head fixed. Amplitudes of the vertical and horizontal components varied linearly with the starting position of the eye. The slopes of the linear-regression lines provided an estimate of the sensitivity of these components to initial eye position. In observations on 29 sites in nine cats, the vertical and horizontal components of saccades evoked from a given site were rarely influenced to the same degree by initial eye position. For most sites, the horizontal component was more sensitive than the vertical component. Sensitivities of vertical and horizontal components were lowest near the representations of the horizontal and vertical meridians, respectively, of the collicular retinotopic map, but otherwise exhibited no systematic retinotopic dependence. Estimates of component amplitudes for saccades evoked from the center of the oculomotor range also diverged significantly from those predicted from the retinotopic map. The results of this and previous studies indicate that electrical stimulation of the cat's superior colliculus cannot yield a unique oculomotor map or one that is in register everywhere with the sensory retinotopic map. Several features of these observations suggest that electrical stimulation of the colliculus produces faulty activation of a saccadic control system that computes target position with respect to the head and that small and large saccades are controlled differently.

scholarly journals Electrical stimulation of superior colliculus affects strabismus angle in monkey models for strabismus

2017 ◽  
Vol 117 (3) ◽  
pp. 1281-1292 ◽  
Author(s):  
Suraj Upadhyaya ◽  
Hui Meng ◽  
Vallabh E. Das
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Superior Colliculus ◽  
Saccadic Eye Movements ◽  
Topographic Map ◽  
Neural Basis ◽  
Deep Layers ◽  
Fixation Task ◽  
Saccade Direction ◽  
Stimulation Of

Disruption of binocular vision during the critical period for development leads to eye misalignment in humans and in monkey models. We have previously suggested that disruption within a vergence circuit could be the neural basis for strabismus. Electrical stimulation in the rostral superior colliculus (rSC) leads to vergence eye movements in normal monkeys. Therefore, the purpose of this study was to investigate the effect of SC stimulation on eye misalignment in strabismic monkeys. Electrical stimulation was delivered to 51 sites in the intermediate and deep layers of the SC (400 Hz, 0.5-s duration, 10–40 μA) in 3 adult optical prism-reared strabismic monkeys. Scleral search coils were used to measure movements of both eyes during a fixation task. Staircase saccades with horizontal and vertical components were elicited by stimulation as predicted from the SC topographic map. Electrical stimulation also resulted in significant changes in horizontal strabismus angle, i.e., a shift toward exotropia/esotropia depending on stimulation site. Electrically evoked saccade vector amplitude in the two eyes was not significantly different ( P > 0.05; paired t-test) but saccade direction differed. However, saccade disconjugacy accounted for only ~50% of the change in horizontal misalignment while disconjugate postsaccadic movements accounted for the other ~50% of the change in misalignment due to electrical stimulation. In summary, our data suggest that electrical stimulation of the SC of strabismic monkeys produces a change in horizontal eye alignment that is due to a combination of disconjugate saccadic eye movements and disconjugate postsaccadic movements. NEW & NOTEWORTHY Electrical stimulation of the superior colliculus in strabismic monkeys results in a change in eye misalignment. These data support the notion of developmental disruption of vergence circuits leading to maintenance of eye misalignment in strabismus.

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