Which of these neurotransmitters is excitatory?
GABA
Serocetylamine
Glutamate
The correct answer and explanation is:
The correct answer is Glutamate.
Glutamate is the primary excitatory neurotransmitter in the brain. It plays a key role in synaptic transmission, where it helps to increase the likelihood that a neuron will fire an action potential. Glutamate functions by binding to receptors on the postsynaptic membrane, which leads to the influx of sodium and calcium ions into the neuron. This depolarizes the neuron, bringing it closer to the threshold needed to trigger an action potential. As a result, glutamate has a central role in processes like learning, memory, and neuroplasticity.
On the other hand, GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter in the central nervous system. It works by binding to GABA receptors on neurons, leading to an influx of chloride ions or the efflux of potassium ions, both of which make the neuron more negatively charged and less likely to fire an action potential. This inhibitory effect is crucial for maintaining balance and preventing excessive neuronal activity, which can lead to conditions like seizures.
Serotonin, which is the other neurotransmitter mentioned, can be excitatory or inhibitory depending on the type of receptor it binds to. Serotonin’s effects are more complex, as it influences mood, anxiety, and other aspects of behavior and physiology. It acts on various receptor subtypes, some of which may produce excitatory effects, while others may have inhibitory effects.
In summary, glutamate is the major excitatory neurotransmitter, and its role is essential for excitatory neurotransmission and the proper functioning of neural circuits involved in cognitive functions.