Answer
A neural circuit is a network of neurons arranged to process/transmit specific types of information.
These networks have different arrangements in the body and serve different functions.
The four common types of neural circuits are the divergent, convergent, reverberating, and parallel after-discharge
Work Step by Step
In a divergent circuit . a single presynaptic neuron stimulates more and more postsynaptic neurons farther from the origin of the stimulus. This enables one postsynaptic neuron to influence several postsynaptic neurons at the same time. This facilitites coordination of activities, for example, the contraction of muscle fibers, or the secretion of glands.
In a convergent circuit, several presynaptic neurons synapse with a single post synaptic output neuron . This increases the effectiveness of a stimulation. For example, messages from several parts of the brain may converge at a postsynaptic neuromuscular junction.
In reverberating circuits, stimuli may cycle through the circuit repeatedly before exciting an effect, or being inhibited. In this kind of circuit, the input neuron stimulates the second neuron which stimulates the third, and so on. But branches of the circuits may develop and these neurons return the signal backward, again and again in the original circuit. The circuit is often ended by inhibitiry outputs. This type of circuit functions in breathing , in waking up, and in the operation of short term memory.
The fourth type of neural circuit is the parallel after-discharge circuit. In this type of circuit a single presynaptic neuron stimulates a group of postsynaptic neurons. Each group ends up synapsing with one final output post synaptic neuron. The number of synapses in each chain-- from common original input neuron to final common out put neuron-- is different for each chain. The result is that the postsynaptic delay in each chain of the circuit is different. This difference is expressed as multiple EPSPs or multiple IPSPs at the output neuron. This kind of circuit is important in the execution of precise activities as in mathematical calculations.
