Neurotransmitters

Definition

Neurotransmitters are chemical messengers that transmit signals across a synapse from one neuron to another in the nervous system. They play a crucial role in facilitating communication between neurons, affecting various functions such as mood, memory, and motor control, ultimately contributing to the overall organization and operation of both the central and peripheral nervous systems.

5 Must Know Facts For Your Next Test

1. There are over 100 different neurotransmitters identified, with each playing specific roles in various physiological processes.
2. Common neurotransmitters include dopamine, serotonin, and acetylcholine, which are crucial for regulating mood, cognition, and muscle movement.
3. Neurotransmitters are synthesized in the presynaptic neuron and stored in vesicles until they are released into the synaptic cleft upon nerve stimulation.
4. The balance between excitatory and inhibitory neurotransmitters is essential for maintaining homeostasis in neural communication.
5. Disruptions in neurotransmitter function can lead to various neurological and psychiatric disorders, such as depression, anxiety, and schizophrenia.

Review Questions

• How do neurotransmitters facilitate communication within the central and peripheral nervous systems?
  • Neurotransmitters facilitate communication by transmitting signals across synapses from one neuron to another. When a neuron is activated, it releases neurotransmitters into the synaptic cleft, where they bind to receptors on the postsynaptic neuron. This binding can either excite or inhibit the next neuron’s activity, thus propagating or modulating the signal throughout both the central and peripheral nervous systems.
• Discuss the roles of excitatory and inhibitory neurotransmitters in maintaining balance within neural circuits.
  • Excitatory neurotransmitters increase the likelihood of the postsynaptic neuron firing an action potential, while inhibitory neurotransmitters decrease this likelihood. This balance is crucial for proper neural circuit functioning, allowing for appropriate responses to stimuli. If there is an imbalance, such as excessive excitatory signals or insufficient inhibition, it can lead to overstimulation or underactivity of neural pathways, potentially resulting in disorders like epilepsy or depression.
• Evaluate how disruptions in neurotransmitter systems can lead to neurological disorders and what this implies for treatment approaches.
  • Disruptions in neurotransmitter systems can significantly impact brain function and behavior, leading to conditions like anxiety disorders, mood disorders, and neurodegenerative diseases. For instance, decreased serotonin levels are linked to depression. Understanding these connections helps inform treatment strategies such as using selective serotonin reuptake inhibitors (SSRIs) that target specific neurotransmitter systems. By restoring balance within these systems, effective management of symptoms can be achieved.

Related terms

Synapse: The junction between two neurons where neurotransmitters are released to transmit signals.

Receptors: Proteins on the surface of neurons that bind to neurotransmitters, initiating a response in the receiving cell.

Excitatory and Inhibitory Neurotransmitters: Types of neurotransmitters; excitatory neurotransmitters increase the likelihood of a neuron firing an action potential, while inhibitory neurotransmitters decrease it.