Feedback

In feedback circuits, the higher order cells begin connections to the lower order cells. The connections might be excitatory but are more typically made through inhibitory interneurons to cause feedback inhibition; the neural is equivalent of the negative feedback. The Feedback inhibition permits motor systems to correct mistakes during the execution of the movement. A neuron might feedback on itself by making the recurrent connections. The Recurrent excitation as shown in figure by axon collaterals is significant in the hippocampus, whereas the recurrent inhibition shown in figure below of motor neurons in the spinal cord by the Renshaw cells is vital.

                          Figure: The Recurrent excitation in the CA3 area of the hippocampus

Figure: The Feedback (i.e., recurrent) inhibition. The Excitatory neurons are open circles, while the inhibitory neurons are filled circles.