How inhibitory circuits in the thalamus serve vision?

How inhibitory circuits in the thalamus serve vision?

The visual sector of the overlying thalamic reticular nucleus receives input from relay cells and supplies feedback inhibition to them in return. Together, these two inhibitory circuits influence all information transmitted from the retina to the primary visual cortex.

Is the thalamus involved in visual processing?

In the visual system, the thalamus receives input from the retina, which is relayed to the brain via the optic nerve. The thalamus not only relays the information but also processes it, as each of the primary sensory relay areas receives information back from the cerebral cortex (called back projections).

Where does the inhibition of the thalamic neurons take place?

The thalamus receives inhibitory afferents from the thalamic reticular nucleus (TRN) as well as from extrathalamic sources. These two types of inhibition display major differences in connectivity, synaptic organization and physiology suggesting distinct functions.

Which area in the thalamus is specialized to receive and process direct visual information from the retina?

lateral geniculate nucleus
For example, visual information from your retina travels to the lateral geniculate nucleus of the thalamus, which is specialized to handle visual information, before being sent on to the primary visual cortex (the main area for visual processing in the brain).

How is the thalamus related to vision?

The visual thalamus is classically known to relay visual stimuli coming from the retina to the cerebral cortex. Researchers from the Max Planck Institute of Neurobiology now show that although neurons in the mouse visual thalamus connect to both eyes, they establish strong functional connections only with one retina.

What is the main area dedicated to vision in the thalamus?

In the visual system, the lateral geniculate nucleus (LGN) of the dorsal thalamus is the gateway through which visual information reaches the cerebral cortex.

Is the thalamus inhibitory or excitatory?

The ventrolateral thalamus (VL) relays excitatory motor signals to the motor cortex (Graybiel, 1990) and VL lesions lead to severe motor dysfunction in monkeys (Canavan et al., 1989, van Donkelaar et al., 2000).

How does dopamine inhibit the indirect pathway?

The “Indirect pathway” inhibits motor activity. The dorsal striatal neurons expressing the D2-family of dopamine receptors are inhibited by dopamine from the SN. These D2R neurons send inhibitory GABAergic connections to the GPe.

What is the visual thalamus?

In mammals, the visual thalamus, the lateral geniculate nucleus (LGN), relays visual information from the retina to the primary visual cortex (V1) and also receives feedback from V1. Both retinal and cortical inputs are critical to processing visual information within the LGN.

Which layer of the visual cortex does visual input from the thalamus project to?

In the visual system, retinal ganglion cells (RGCs) project directly to the lateral geniculate nucleus (LGN) of the dorsal thalamus, which in turn projects to the primary visual cortex (V1).

Where is the visual cortex located?

the occipital lobe
The primary visual cortex is found in the occipital lobe in both cerebral hemispheres. It surrounds and extends into a deep sulcus called the calcarine sulcus.

Which visual property is processed by the magnocellular layers?

The magnocellular visual stream signals us to an awareness of the time properties of objects. For instance, detection of the movement, distance, and speed of an object moving towards us. ‘Parvocells’ or P-cells carry visual information along the ventral stream of the brain.