Question

Some neurotransmitters act indirectly on a neuron. This means, they cannot ________?

1) Affect the release of other neurotransmitters
2) Bind directly to the neuron's receptors
3) Alter the neuron's membrane potential
4) Activate intracellular signaling pathways

Answer 1

Neurotransmitters that act indirectly do not bind directly to the neuron's receptors but instead, they activate signaling pathways within the cell by triggering a series of molecular events involving second messengers.

Step-by-step explanation:

When neurotransmitters act indirectly on a neuron, they cannot bind directly to the neuron's receptors. Indirect acting neurotransmitters typically activate a receptor which then starts a signaling cascade within the cell through a process that involves secondary messengers. These neurotransmitters generally bind to metabotropic receptors, which activate G proteins, leading to subsequent activation of effector proteins. These effector proteins generate new molecules like cAMP as second messengers, which can then further affect the cell's functions such as metabolism, ion channel status, and even gene transcription.