About amacrine cells
- Amacrine cells are a type of interneuron within the human retina.
- Amacrine cells are located in a central but inaccessible region of retinal circuitry.
- Amacrine cells are driven by and feedback to bipolar cells. They also have junctions with ganglion cells, as well as with each other.
- Amacrine cells are known to add information to the stream of data through bipolar cells and then to control and refine the response of ganglion cells and their subtypes.
- Most amacrine cells don’t have tale-like axons. But whilst they clearly have multiple connections to other neurons around them, research into their precise inputs and outputs is ongoing.
Amacrine cells functions
Amacrine cells are known to contribute to narrowly task-specific visual functions such as:
- Efficient transmission of high fidelity visual information with a good signal-to-noise ratio.
- Maintaining the circadian rhythm which keeps our lives tuned to the cycles of day and night and helps to govern our lives throughout the year.
- Measuring the difference between the response of specific photoreceptors compared with surrounding cells (centre-surround antagonism), so enabling edge detection and contrast enhancement.
- Object motion detection which provides an ability to distinguish between the true motion of an object across the field of view and our own eye movements.
Centre-surround antagonism refers to the way retinal neurons organize their receptive fields.
- The centre component is primed to measure the sum-total of signals received from a small number of cone cells directly connected to a bipolar cell.
- The surround component is primed to measure the sum of signals received from a much larger number of cones around the centre point.
- The two signals are then compared to find the degree to which they disagree.