A periodic production of action potentials that takes place even without synaptic input is referred as........

Correct option is C

Spontaneous firing rate refers to the baseline activity of neurons that fire action potentials periodically without requiring external synaptic input. Some neurons exhibit intrinsic rhythmic activity due to their membrane properties and the presence of pacemaker currents. This spontaneous activity is important for maintaining baseline neural activity and can be modulated by synaptic inputs.

Information Booster:
1. Intrinsic Excitability: Certain neurons possess ion channels that allow them to depolarize spontaneously to threshold without external stimulation
2. Pacemaker Neurons: Found in various brain regions including the thalamus, cerebellum, and brainstem, these neurons maintain rhythmic firing patterns
3. Functional Significance: Spontaneous activity provides a baseline for neural coding - both increases and decreases from baseline can convey information
4. Modulation: While spontaneous, this firing rate can be increased or decreased by excitatory and inhibitory synaptic inputs
5. Clinical Relevance: Abnormal spontaneous firing rates are associated with various neurological conditions including epilepsy and chronic pain

Additional Knowledge:
• Reflex arc (A): A neural pathway involving sensory input, integration, and motor output for reflexive responses
• Temporal summation (B): The process where multiple synaptic inputs occurring close in time combine to reach threshold
• Excitatory potential (D): Refers to excitatory postsynaptic potentials (EPSPs) that result from synaptic input, not spontaneous activity