Double Stimulation in a Spiking Neural Network Model of the Midbrain Superior Colliculus
The midbrain superior colliculus (SC) is a crucial sensorimotor interface in the generation of rapid saccadic gaze shifts. For every saccade it recruits a large population of cells in its vectorial motor map. Supra-threshold electrical microstimulation in the SC reveals that the stimulated site prod...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2018-10-01
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| Series: | Frontiers in Applied Mathematics and Statistics |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fams.2018.00047/full |
| _version_ | 1818935791380856832 |
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| author | Bahadir Kasap A. John van Opstal |
| author_facet | Bahadir Kasap A. John van Opstal |
| author_sort | Bahadir Kasap |
| collection | DOAJ |
| description | The midbrain superior colliculus (SC) is a crucial sensorimotor interface in the generation of rapid saccadic gaze shifts. For every saccade it recruits a large population of cells in its vectorial motor map. Supra-threshold electrical microstimulation in the SC reveals that the stimulated site produces the saccade vector specified by the motor map. Electrically evoked saccades (E-saccades) have kinematic properties that strongly resemble natural, visual-evoked saccades (V-saccades), with little influence of the stimulation parameters. Moreover, synchronous stimulation at two sites yields eye movements that resemble a weighted vector average of the individual stimulation effects. Single-unit recordings have indicated that the SC population acts as a vectorial pulse generator by specifying the instantaneous gaze-kinematics through dynamic summation of the movement effects of all SC spike trains. But how to reconcile the a-specific stimulation pulses with these intricate saccade properties? We recently developed a spiking neural network model of the SC, in which microstimulation initially activates a relatively small set of (~50) neurons around the electrode tip, which subsequently sets up a large population response (~5,000 neurons) through lateral synaptic interactions. Single-site microstimulation in this network thus produces the saccade properties and firing rate profiles as seen in single-unit recording experiments. We here show that this mechanism also accounts for many results of simultaneous double stimulation at different SC sites. The resulting E-saccade trajectories resemble a weighted average of the single-site effects, in which stimulus current strength of the electrode pulses serve as weighting factors. We discuss under which conditions the network produces effects that deviate from experimental results. |
| first_indexed | 2024-12-20T05:25:47Z |
| format | Article |
| id | doaj.art-670e2c6f7723496e97416d484c4bfe1f |
| institution | Directory Open Access Journal |
| issn | 2297-4687 |
| language | English |
| last_indexed | 2024-12-20T05:25:47Z |
| publishDate | 2018-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Applied Mathematics and Statistics |
| spelling | doaj.art-670e2c6f7723496e97416d484c4bfe1f2022-12-21T19:51:53ZengFrontiers Media S.A.Frontiers in Applied Mathematics and Statistics2297-46872018-10-01410.3389/fams.2018.00047414130Double Stimulation in a Spiking Neural Network Model of the Midbrain Superior ColliculusBahadir KasapA. John van OpstalThe midbrain superior colliculus (SC) is a crucial sensorimotor interface in the generation of rapid saccadic gaze shifts. For every saccade it recruits a large population of cells in its vectorial motor map. Supra-threshold electrical microstimulation in the SC reveals that the stimulated site produces the saccade vector specified by the motor map. Electrically evoked saccades (E-saccades) have kinematic properties that strongly resemble natural, visual-evoked saccades (V-saccades), with little influence of the stimulation parameters. Moreover, synchronous stimulation at two sites yields eye movements that resemble a weighted vector average of the individual stimulation effects. Single-unit recordings have indicated that the SC population acts as a vectorial pulse generator by specifying the instantaneous gaze-kinematics through dynamic summation of the movement effects of all SC spike trains. But how to reconcile the a-specific stimulation pulses with these intricate saccade properties? We recently developed a spiking neural network model of the SC, in which microstimulation initially activates a relatively small set of (~50) neurons around the electrode tip, which subsequently sets up a large population response (~5,000 neurons) through lateral synaptic interactions. Single-site microstimulation in this network thus produces the saccade properties and firing rate profiles as seen in single-unit recording experiments. We here show that this mechanism also accounts for many results of simultaneous double stimulation at different SC sites. The resulting E-saccade trajectories resemble a weighted average of the single-site effects, in which stimulus current strength of the electrode pulses serve as weighting factors. We discuss under which conditions the network produces effects that deviate from experimental results.https://www.frontiersin.org/article/10.3389/fams.2018.00047/fullsaccadesmotor mapspatial-temporal transformationelectrical stimulationpopulation codingvector averaging |
| spellingShingle | Bahadir Kasap A. John van Opstal Double Stimulation in a Spiking Neural Network Model of the Midbrain Superior Colliculus Frontiers in Applied Mathematics and Statistics saccades motor map spatial-temporal transformation electrical stimulation population coding vector averaging |
| title | Double Stimulation in a Spiking Neural Network Model of the Midbrain Superior Colliculus |
| title_full | Double Stimulation in a Spiking Neural Network Model of the Midbrain Superior Colliculus |
| title_fullStr | Double Stimulation in a Spiking Neural Network Model of the Midbrain Superior Colliculus |
| title_full_unstemmed | Double Stimulation in a Spiking Neural Network Model of the Midbrain Superior Colliculus |
| title_short | Double Stimulation in a Spiking Neural Network Model of the Midbrain Superior Colliculus |
| title_sort | double stimulation in a spiking neural network model of the midbrain superior colliculus |
| topic | saccades motor map spatial-temporal transformation electrical stimulation population coding vector averaging |
| url | https://www.frontiersin.org/article/10.3389/fams.2018.00047/full |
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