Question

Glutamate is known to be the major excitatory neurotransmitter in mammals. Glutamate does NOT A. depend on its receptors in whether it will be excitatory or inhibitory. B. become released into the synaptic cleft by vesicles. C. mediate epileptogenesis via its receptors. D. All of the above

Short answer

None of the options (A, B, C, or D) are correct.

Step-by-step solution

Understanding the Prompt

The exercise is asking which statement is NOT true about the neurotransmitter glutamate.

Analyze Option A

Option A states that glutamate does not depend on its receptors in whether it will be excitatory or inhibitory. This statement is false because glutamate is indeed excitatory and this is determined by its interaction with its receptors.

Analyze Option B

Option B states that glutamate does not become released into the synaptic cleft by vesicles. This statement is also false because glutamate is released into the synaptic cleft by vesicles in the process of neurotransmission.

Analyze Option C

Option C states that glutamate does not mediate epileptogenesis via its receptors. This statement is false because glutamate is known to be involved in epileptogenesis through its action on its receptors.

Analyze Option D

Option D states 'All of the above.' Since all the provided statements (A, B, and C) are false, this indicates that D is not a correct summary of true statements. Therefore, it is also not correct.

Final Decision

Given that all options A, B, and C are statements that are actually true about glutamate, none of them correctly represent what glutamate does NOT do.

Key concepts

Excitatory Neurotransmitter

Glutamate is a crucial excitatory neurotransmitter in the human brain. This means it plays a vital role in activating neurons to send signals. When glutamate is released, it binds to specific receptors on neighboring neurons and triggers an excitatory response.
This increases the likelihood that the receiving neuron will generate its action potential and continue the communication chain.
The main point to remember is that glutamate helps facilitate neural activity, making it a key player in many brain functions, including learning and memory.

Synaptic Cleft

The synaptic cleft is the small gap between neurons at a synapse. When a neuron sends a signal, it releases neurotransmitters like glutamate from synaptic vesicles into this gap.
These neurotransmitters cross the synaptic cleft and bind to receptors on the neighboring neuron, continuing the communication process.
This space is critical for proper neurotransmission, allowing precise control over signal transmission between neurons. It's like a bridge that connects one neuron to another, ensuring messages are passed accurately and efficiently.

Vesicle Release

Vesicle release is a fundamental process in neurotransmission. Inside the neuron, neurotransmitters like glutamate are stored in small sacs called vesicles.
When an action potential reaches the end of a neuron, these vesicles fuse with the neuron's membrane and release their contents into the synaptic cleft.
This process allows neurotransmitters to travel across the synaptic gap and interact with receptors on the next neuron. It's an essential step that ensures the continuity of neural signaling.

Receptor Interaction

Receptors are specialized proteins on the surface of neurons that bind to neurotransmitters like glutamate. This binding triggers a response in the receiving neuron.
There are several types of glutamate receptors, including NMDA, AMPA, and kainate receptors. Each type responds differently, contributing to various aspects of neural communication.
Understanding receptor interaction is key to knowing how excitatory signals are propagated and regulated within the brain. It's like a lock-and-key mechanism where the neurotransmitter (key) must fit into the receptor (lock) to open the door for further signaling.

Epileptogenesis

Epileptogenesis is the process by which a normal brain becomes prone to seizures and epilepsy. Glutamate can play a significant role in this process.
Overactivation of glutamate receptors may lead to excessive excitation of neurons, potentially causing seizures. This excessive neuronal activity can disrupt normal brain function and contribute to the development of epilepsy.
It's important to understand how glutamate's action on its receptors can influence epileptogenesis, as this knowledge can help in developing treatments for seizure disorders.