Which statement accurately describes the roles of GABA and glutamate in neural signaling?

Which statement accurately describes the roles of GABA and glutamate in neural signaling?

• A. GABA is the primary inhibitory neurotransmitter and glutamate is the primary excitatory neurotransmitter.
• B. GABA is excitatory and glutamate is inhibitory.
• C. GABA and glutamate are both inhibitory.
• D. GABA and glutamate are unrelated to neural excitability.

Answer: (A)

Neural signaling hinges on a balance between inhibition and excitation, mainly governed by two key neurotransmitters. GABA is the primary inhibitory neurotransmitter in the adult brain, typically producing hyperpolarization by opening chloride channels (GABA-A) or by modulating ion channels and second messenger systems (GABA-B), which makes neurons less likely to fire. Glutamate is the primary excitatory neurotransmitter, activating NMDA, AMPA, and kainate receptors to allow positive ions into the neuron, leading to depolarization and a higher chance of firing. This pairing keeps neural circuits stable, supports precise signaling, and underpins learning and memory through regulated excitation and inhibition. While development can show occasional exceptions where GABA is excitatory due to different chloride gradients, the standard roles in the mature nervous system are clear: GABA inhibits, glutamate excites.

Neural signaling hinges on a balance between inhibition and excitation, mainly governed by two key neurotransmitters. GABA is the primary inhibitory neurotransmitter in the adult brain, typically producing hyperpolarization by opening chloride channels (GABA-A) or by modulating ion channels and second messenger systems (GABA-B), which makes neurons less likely to fire. Glutamate is the primary excitatory neurotransmitter, activating NMDA, AMPA, and kainate receptors to allow positive ions into the neuron, leading to depolarization and a higher chance of firing. This pairing keeps neural circuits stable, supports precise signaling, and underpins learning and memory through regulated excitation and inhibition. While development can show occasional exceptions where GABA is excitatory due to different chloride gradients, the standard roles in the mature nervous system are clear: GABA inhibits, glutamate excites.