Neurotransmitters

Definition

Neurotransmitters are chemical messengers that transmit signals across synapses between neurons and other target cells. They play a crucial role in cellular signaling and signal transduction by enabling communication within the nervous system, affecting everything from muscle contraction to mood regulation.

5 Must Know Facts For Your Next Test

1. Neurotransmitters can be classified into different types, such as excitatory and inhibitory, depending on their effects on target cells.
2. Common neurotransmitters include serotonin, dopamine, norepinephrine, and acetylcholine, each having distinct roles in brain function and behavior.
3. The release of neurotransmitters is triggered by the arrival of an action potential at the axon terminal of a neuron.
4. After binding to their receptors, neurotransmitters can either be reabsorbed by the releasing neuron through reuptake or broken down by enzymes.
5. Dysregulation of neurotransmitter systems is associated with various neurological and psychiatric disorders, such as depression, anxiety, and schizophrenia.

Review Questions

• How do neurotransmitters facilitate communication between neurons?
  • Neurotransmitters facilitate communication between neurons by being released from the axon terminal of one neuron into the synapse. When they reach the target neuron, they bind to specific receptors on its surface, leading to a change in the electrical state of the target cell. This process allows for either excitation or inhibition of the next neuron, effectively transmitting signals throughout the nervous system.
• Discuss the role of neurotransmitters in modulating synaptic transmission and how this affects overall neural communication.
  • Neurotransmitters play a key role in modulating synaptic transmission by influencing the likelihood of an action potential occurring in the post-synaptic neuron. Excitatory neurotransmitters increase this likelihood, while inhibitory neurotransmitters decrease it. This delicate balance is essential for maintaining proper neural communication, as it allows for fine-tuning of neuronal responses to stimuli and helps regulate various functions such as reflexes, emotions, and cognitive processes.
• Evaluate how disruptions in neurotransmitter systems can lead to neurological disorders and impact behavior.
  • Disruptions in neurotransmitter systems can lead to a range of neurological disorders due to their critical role in regulating mood, cognition, and motor functions. For instance, an imbalance in serotonin levels is linked to depression and anxiety, while abnormal dopamine signaling is associated with schizophrenia and Parkinson's disease. These disruptions affect neural communication pathways, leading to altered behaviors and cognitive functions. Understanding these connections can inform treatment strategies aimed at restoring balance within neurotransmitter systems.

Related terms

Synapse: The junction between two neurons where neurotransmitters are released, allowing for signal transmission.

Receptors: Proteins on the surface of target cells that bind to neurotransmitters, triggering a response in the cell.

Action Potential: A temporary reversal of the electrical charge across a neuron's membrane, which is essential for the propagation of nerve impulses.