Neuron Structure and Communication Quiz

Neuron Structure

• Glia: Support cells responsible for creating myelin sheath, which insulates axons.
• Dendrite: Receives signals from other neurons.
• Axon: Transmits electrical signals.
• Terminal branches: Release neurotransmitters into the synapse.

Neuronal Communication

• Electrical and Chemical Signaling:
  • Electrical: Changes in voltage within the neuron, traveling from dendrites, down the axon, to the terminals.
  • Chemical: Neurotransmitters released from terminal branches, crossing the synapse to bind with receptors on the dendrites of the next neuron.

Electrical Signals

• Action Potential (AP): Rapid change in voltage within a neuron caused by stimulation exceeding a critical threshold.
• Resting Potential (RP): Neuron is negatively polarized (-70 mV).
• Depolarization: Sufficient stimulation at the dendrite opens ion channels, allowing sodium ions (Na+) to enter, making the neuron more positive.
• Repolarization: Potassium ions (K+) leave the neuron, returning it to a negative charge.
• Refractory Period: Short period after an AP when the neuron is unable to fire another AP as it returns to resting potential.
• All-or-None Principle: An AP is fired once the resting potential threshold is met.
• Excitatory Signals: Promote the firing of an AP.
• Inhibitory Signals: Prevent or decrease the likelihood of an AP.

Chemical Signals

• Neurotransmission: Chemical communication between neurons.
  • Amino Acids:
    • Glutamate: Primary excitatory neurotransmitter, triggering APs.
    • GABA: Primary inhibitory neurotransmitter, preventing APs.
  • Monoamines:
    • Norepinephrine: Involved in the "fight or flight" response.
    • Dopamine: Associated with reward and pleasure.
    • Serotonin: Contributes to mood regulation.
  • Acetylcholine: Involved in muscle control, learning, and memory.
• Synapse: The space between the terminal branches of the sending neuron and the dendrites of the receiving neuron.
• Receptors: Specific proteins on the dendrites that bind to specific neurotransmitters.

Artificial Transmission

• Psychoactive Drugs: Influence neurotransmitter activity.
  • Agonist: Mimics the action of a neurotransmitter.
  • Antagonist: Blocks neurotransmission.

Genes and Environment

• Allele: Variant of a gene, with two alleles inherited from each parent (one dominant, one recessive).
• Epigenetics: Study of how the environment can influence gene expression.

Behavioral Genetics

• Behavioral Genetics: Investigates how genetic factors contribute to variations in traits among individuals within a population.
• Heritability: A measure of how much variation in a phenotype can be attributed to genetic differences.

Test your knowledge on the intricate structure of neurons and the processes of neuronal communication. This quiz covers key concepts such as glia, dendrites, axons, and the mechanisms of electrical and chemical signaling. Explore how action potentials and resting potentials influence neuronal activity.