Lateral inhibition

As lateral inhibition ( inhibition environment, lateral inhibition, Lateralhemmung or Lateralinhibition ) is called in neurobiology a Verschaltungsprinzip of nerve cells of the neurophysiological processing of stimuli and in cell biology and developmental biology a mechanism, genetic selection with the individual cells.

Verschaltungsprinzip the lateral inhibition

The drawing on the right side simplifies the understanding of this principle. On display are three receptors, for example on the surface of the skin. The outer two are more excited than the inner receptor. The adjacent numbers are arbitrary relative units to provide information about the strength. The larger the number, the greater the excitement. Positive, red numbers are arousing, negative, green numbers are inhibitory. The strength of the excitation is now converted and passed to an action potential frequency. The Verschaltungsschema above shows inhibitory interneurons that transform an exciting incoming signal ( afferent ) in an inhibitory ( inhibitory ) continued leading signal. The switch of excitation in the inhibition occurs ( locking: GABA, glycine, adrenaline) by means of different neurotransmitters. Through these inhibitory interneurons the next-door transmission is attenuated to a so-called second neuron. This attenuation is proportional to the excitation of the inter- neuron ( inhibition: negative, green numbers in the figure) by simply summing the excitatory and inhibitory influences on the second neuron results in a contrast enhancement. This is represented by the diagram on the left graph.

Lateral inhibition as a general principle

Lateral inhibition is a general principle which is used anywhere in the central nervous system. It occurs in complicated interwoven circuits as they are located, for example in the ganglion cell nodes or the eye in the upper layers of the retina.

In the retina, inhibitory interneurons are referred to as horizontal cells and serve the lateral interconnection of the photoreceptors ( rods and cones ). However, to enhance the image contrast, and rapid detection of movements of the retina has not more complex possibilities of interconnection. The result of lateral inhibition is mainly the contrast enhancement and thus the emergence of shape boundaries that can serve as the basis of spatial orientation.