Mohamad Hafiz Abd Rahim 1. Reason out the following: Reciprocal inhibition circuit prevents overactivity of the brain. To avoid the abnormally high sensitivity that could lead to almost continuous muscle cramps, convulsion, psychotic disturbances, hallucinations, tension, and other nervous disorder To adjust the sensitivity in each circuit to almost the exact level required for proper functions
2. Why is it important for a signal to be prolonged? Give examples of appropriate situations.
The prolongation is important in order to regulate the alertness or sensitivity of the neuronal impulse and also help the organ to detect the impulse and give feedback to the impulse.
The example is excitatory signal from a neuron in the spinal cord causing forward movement of a leg whereas inhibitory signal through separate neurons to back muscles leg not to oppose the forward movement.
3. Describe the mechanisms involved in prolongation of the signal.
a) Synaptic after discharge
When an excitatory synapse discharges on the surfaces of dendrites or soma, a postsynaptic potential develops last longer because of the long-acting synaptic transmitters. As long the potential last, it will continue to excite the neuron to transmit a continuous train of output impulses. Therefore, single instantaneous input can cause a sustained signal output, a series of repetitive discharges that lasting for many milliseconds. b) Reverberatory (Oscillatory) circuit It caused by positive feedback within the neuronal network. The output of a neuronal circuit feeds back to re-excite the input of the same circuit. Once stimulated, the circuit discharges repetitively for a long time.