Saltatory conduction (a) requires more energy than...

Saltatory conduction (a) requires more energy than continuous conduction (b) occurs in unmyelinated neurons
(c) occurs when the action potential jumps from one node of Ranvier to the next (d) slows transmission of an impulse
(e) depends on the action of GABA

Key Concepts

Energy Efficiency in Neural Conduction

Saltatory conduction is more energy efficient compared to continuous conduction because the regeneration of the action potential occurs only at the nodes of Ranvier, reducing the overall ionic exchange and the energetic cost associated with restoring the resting membrane potential.

GABA and Neurotransmission

Gamma-aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the brain, working at synapses to modulate neuronal activity. It is not involved in the mechanism of saltatory conduction, which relates to the propagation of action potentials along axons.

Continuous Conduction

This is the propagation of an action potential along an unmyelinated axon, where the depolarization wave moves along every part of the membrane in a sequential manner. It is generally slower and less energy efficient compared to saltatory conduction.

Saltatory Conduction

This is the mechanism by which action potentials jump from one node of Ranvier to the next along a myelinated axon. It is a key adaptation in vertebrate nervous systems that significantly increases the speed of nerve impulse transmission compared to a continuous wave of depolarization.

Myelination

Myelination refers to the process by which axons are insulated by a fatty layer called myelin, produced by oligodendrocytes in the CNS and Schwann cells in the PNS. This insulation reduces ion leakage and capacitance, thereby allowing electrical impulses to propagate faster and more efficiently along the axon.

Nodes of Ranvier

These are periodic gaps in the myelin sheath along a myelinated axon where the axonal membrane is exposed. At these nodes, voltage-gated ion channels are concentrated, enabling the regeneration of the action potential as it travels down the axon.

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