The Role of the Superior Colliculus in Fast and Slow Gaze Orientation

1996 ◽  
pp. 165-183
Author(s):  
A. Roucoux ◽  
M. Missal ◽  
M. Crommelinck ◽  
P. Lefevre
Keyword(s):  
Superior Colliculus

Effects of Local Nicotinic Activation of the Superior Colliculus on Saccades in Monkeys

2005 ◽  
Vol 93 (1) ◽  
pp. 519-534 ◽  
Author(s):  
Masayuki Watanabe ◽  
Yasushi Kobayashi ◽  
Yuka Inoue ◽  
Tadashi Isa
Keyword(s):  
Superior Colliculus ◽  
Reaction Times ◽  
Low Frequency ◽  
Visually Guided ◽  
Population Activity ◽  
Affected Area ◽  
Movement Field ◽  
Neural Interactions ◽  
Restricted Region

To examine the role of competitive and cooperative neural interactions within the intermediate layer of superior colliculus (SC), we elevated the basal SC neuronal activity by locally injecting a cholinergic agonist nicotine and analyzed its effects on saccade performance. After microinjection, spontaneous saccades were directed toward the movement field of neurons at the injection site (affected area). For visually guided saccades, reaction times were decreased when targets were presented close to the affected area. However, when visual targets were presented remote from the affected area, reaction times were not increased regardless of the rostrocaudal level of the injection sites. The endpoints of visually guided saccades were biased toward the affected area when targets were presented close to the affected area. After this endpoint effect diminished, the trajectories of visually guided saccades remained modestly curved toward the affected area. Compared with the effects on endpoints, the effects on reaction times were more localized to the targets close to the affected area. These results are consistent with a model that saccades are triggered by the activities of neurons within a restricted region, and the endpoints and trajectories of the saccades are determined by the widespread population activity in the SC. However, because increased reaction times were not observed for saccades toward targets remote from the affected area, inhibitory interactions in the SC may not be strong enough to shape the spatial distribution of the low-frequency preparatory activities in the SC.

GABAA and GABAC Receptors Have Contrasting Effects on Excitability in Superior Colliculus

1999 ◽  
Vol 82 (4) ◽  
pp. 2020-2023 ◽  
Author(s):  
Michael Pasternack ◽  
Mathias Boller ◽  
Belinda Pau ◽  
Matthias Schmidt
Keyword(s):  
Superior Colliculus ◽  
Receptor Agonist ◽  
Brain Slices ◽  
Superficial Layer ◽  
Field Potentials ◽  
Competitive Antagonist ◽  
Postsynaptic Potential ◽  
Late Potential ◽  
Receptor Agonists And Antagonists

We have recently found that GABAC receptor subunit transcripts are expressed in the superficial layers of rat superior colliculus (SC). In the present study we used immunocytochemistry to demonstrate the presence of GABAC receptors in rat SC at protein level. We also investigated in acute rat brain slices the effect of GABAA and GABAC receptor agonists and antagonists on stimulus-evoked extracellular field potentials in SC. Electrical stimulation of the SC optic layer induced a biphasic, early and late, potential in the adjacent superficial layer. The late component was completely inhibited by 6-cyano-7-nitroquinoxaline-2,3-dione or CoCl2, indicating that it was generated by postsynaptic activation. Muscimol, a potent GABAA and GABAC receptor agonist, strongly attenuated this postsynaptic potential at concentrations >10 μM. In contrast, the GABAC receptor agonist cis-aminocrotonic acid, as well as muscimol at lower concentrations (0.1–1 μM) increased the postsynaptic potential. This increase was blocked by (1,2,5,6-tetrahydropyridine-4-yl)methylphosphinic acid, a novel competitive antagonist of GABAC receptors. Our findings demonstrate the presence of functional GABAC receptors in SC and suggest a disinhibitory role of these receptors in SC neuronal circuitry.

scholarly journals Amygdala Underlies the Environment Dependency of Defense Responses Induced via Superior Colliculus

2022 ◽  
Vol 15 ◽  
Author(s):  
Kaoru Isa ◽  
Kota Tokuoka ◽  
Sakura Ikeda ◽  
Sara Karimi ◽  
Kenta Kobayashi ◽  
...  
Keyword(s):  
Superior Colliculus ◽  
Natural Environment ◽  
Ibotenic Acid ◽  
Defense Responses ◽  
Male Mice ◽  
Contextual Modulation ◽  
Innate Defense ◽  
Open Platform ◽  
Environmental Setting

In our previous study, we showed that the defense responses induced by the selective optogenetic activation of the uncrossed output pathway from the deeper layer of the superior colliculus were environment dependent in the mouse. In a small closed box, the stimulus frequently induced flight (fast forward run away) responses, while in a large open field, the stimulus tended to induce backward retreat responses. We tested a hypothesis that the amygdala is involved in such environment dependency of the innate defense responses. For this purpose, we made a bilateral lesion of the amygdala induced by the ibotenic acid injections in male mice. As a result, in the mice with lesions of substantial portions of the basolateral and basomedial complex, the flight responses in the closed box disappeared and retreat responses were mainly induced. The retreat responses on the open platform were unchanged. Classically, the amygdala has been considered to be involved in the memory-dependent contextual modulation of the fear responses. In contrast, the present results suggest a novel view on the role of the amygdala in which the amygdala plays a key role in sensing the current environmental setting for making a quick decision of action upon emergency, which is critical for survival in the natural environment.

Critical role of superior colliculus in enhancing behavioral accuracy but not reaction time by audiovisual integration

2009 ◽  
Vol 65 ◽  
pp. S171
Author(s):  
Junya Hirokawa ◽  
Osamu Sadakane ◽  
Shuzo Sakata ◽  
Miquel Bosch ◽  
Yoshio Sakurai ◽  
...  
Keyword(s):  
Reaction Time ◽  
Superior Colliculus ◽  
Critical Role ◽  
Audiovisual Integration

scholarly journals Perturbation of Combined Saccade-Vergence Movements by Microstimulation in Monkey Superior Colliculus

1999 ◽  
Vol 81 (5) ◽  
pp. 2279-2296 ◽  
Author(s):  
Vivek Chaturvedi ◽  
Jan A. M. van Gisbergen
Keyword(s):  
Superior Colliculus ◽  
Local Population ◽  
Three Dimensional ◽  
Weighted Averaging ◽  
Target Onset ◽  
Saccade Onset ◽  
Different Depths

Perturbation of combined saccade-vergence movements by microstimulation in monkey superior colliculus. This study investigated the role of the monkey superior colliculus (SC) in the control of visually (V)-guided combined saccade-vergence movements by assessing the perturbing effects of microstimulation. We elicited an electrical saccade (E) by stimulation (in 20% of trials) in the SC while the monkey was preparing a V-guided movement to a near target. The target was aligned such that E- and V-induced saccades had similar amplitudes but different directions and such that V-induced saccades had a significant vergence component (saccades to a near target). The onset of the E-stimulus was varied from immediately after V-target onset to after V-saccade onset. E-control trials, where stimulation was applied during fixation of a V-target, yielded the expected saccade but no vergence. By contrast, early perturbation trials, where the E-stimulus was applied soon after the onset of the V-target, caused an E-triggered response with a clear vergence component toward the V-target. Midflight perturbation, timed to occur just after the monkey initiated the movement toward the target, markedly curtailed the ongoing vergence component during the saccade. Examination of pooled responses from both types of perturbation trials showed weighted-averaging effects between E- and V-stimuli in both saccade and fast vergence components. Both components exhibited a progression from E- to V-dominance as the E-stimulus was delayed further. This study shows that artificial intervention in the SC, while a three-dimensional (3D) refixation is being prepared or is ongoing, can affect the timing (when) and the metric specification (where) of both saccades and vergence. To explain this we interpret the absence of overt vergence in the E-controls as being caused by a zero-vergence change command rather than reflecting the mere absence of a collicular vergence signal. In the perturbation trials, the E-evoked zero-vergence signal competes with the V-initiated saccade-vergence signal, thereby giving rise to a compromised 3D response. This effect would be expected if the population of movement cells at each SC site is tuned in 3D, combining the well-known topographical code for direction and amplitude with a nontopographical depth representation. On E-stimulation, the local population would yield a net saccade signal caused by the topography, but the cells coding for different depths would be excited equally, causing the vergence change to be zero.

Diurnal activity rhythm of rats with lesions of superior colliculus and visual cortex

1962 ◽  
Vol 202 (6) ◽  
pp. 1205-1207 ◽  
Author(s):  
Joseph Altman
Keyword(s):  
Superior Colliculus ◽  
Striate Cortex ◽  
Activity Rhythm ◽  
Lesion Group ◽  
Cortex Lesion ◽  
Activity Preference ◽  
Activity Cycles ◽  
Bilateral Lesions ◽  
The Brain

The role of two central nervous visual structures. the superior colliculus and striate cortex, was investigated in the coordination of the day-night activity cycles of rats. While both normal rats and rats with bilateral lesions in superior colliculus or striate cortex showed higher rates of general activity at night than during the day, the brain-operated animals showed less difference than the normals. Decrease in nocturnal activity preference was considerable in the striate cortex lesion group in which mean destruction of tissue was as high as 91%, whereas in the superior colliculus similar effects were obtained with mean destruction of only 41% of tissue.

Injection of Nicotine Into the Superior Colliculus Facilitates Occurrence of Express Saccades in Monkeys

1999 ◽  
Vol 82 (3) ◽  
pp. 1642-1646 ◽  
Author(s):  
Hiroshi Aizawa ◽  
Yasushi Kobayashi ◽  
Masaru Yamamoto ◽  
Tadashi Isa
Keyword(s):  
Superior Colliculus ◽  
Nicotinic Acetylcholine Receptors ◽  
Acetylcholine Receptors ◽  
Marked Change ◽  
Major Change ◽  
Visually Guided ◽  
Express Saccades ◽  
Macaque Monkeys ◽  
The Relationship

To clarify the role of cholinergic inputs to the intermediate layer of the superior colliculus (SC), we examined the effect of microinjection of nicotine into the SC on visually guided saccades in macaque monkeys. After injection of 0.4–2 μl of 1–100 mM nicotine into the SC, frequency of extremely short latency saccades (express saccades; reaction time = 70–120 ms) dramatically increased, for the saccades the direction and amplitude of which were represented at the location of the injection site on the collicular map. However, no marked change was observed for the relationship between the peak velocities and the amplitudes of saccades. These results suggested that activation of nicotinic acetylcholine receptors in the SC can facilitate initiation but causes no major change in dynamics of visually guided saccades.

scholarly journals Role of the superior colliculus in the expression of acute and kindled audiogenic seizures in Wistar audiogenic rats

Epilepsia ◽  
2009 ◽  
Vol 50 (12) ◽  
pp. 2563-2574 ◽  
Author(s):  
Maria C. Doretto ◽  
José A. Cortes-de-Oliveira ◽  
Franco Rossetti ◽  
Norberto Garcia-Cairasco
Keyword(s):  
Superior Colliculus ◽  
Audiogenic Seizures
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