Neurophysiology

Glial Cells

• Non-neuronal cells in the nervous system that provide support and maintenance functions are known as glial cells.
• Astrocytes are a type of glial cell that connect neurons with blood vessels.

Myelination

• Schwann cells produce myelin in the peripheral nervous system.
• Oligodendroglia produce myelin in the central nervous system, and their function is to form the myelin sheath around axons.

Neurodegenerative Disorders

• Multiple sclerosis is characterized by the progressive deterioration of myelin.

Microglia

• Microglia are a type of glial cell that function as the resident immune cells of the central nervous system.

Neuronal Structure and Function

• The axon is responsible for transmitting signals in a neuron.
• Dendrites have receptors and synapses that receive signals.
• Dendritic spines are small protrusions on dendrites that receive synaptic inputs.

Alzheimer's Disease

• The organelle implicated in Alzheimer's disease is the Golgi apparatus.

Synaptic Connections

• The term for the loss of the distal part (axon) of a neuron is axotomy.
• Neurobiotaxis occurs in the growth cone.
• The width of a synapse is approximately 20-30 Å.

Neuronal Properties

• Neurons have the special property of excitability, which allows them to generate action potentials.

Axonal Conduction

• The chemical components involved in axonal conduction are ions (Na+, K+, Cl-, and Ca2+).
• The research origin of axonal conduction was the Hodgkin-Huxley model.
• The active channels involved in neuronal conduction are sodium and potassium channels.

Synaptic Transmission

• Synaptic transmission occurs in the synapse, where neurotransmitters are released from the presynaptic terminal and bind to receptors on the postsynaptic terminal.

Neurotransmitters

• Dopamine is responsible for addiction to drugs that produce euphoria.
• Serotonin is derived from the chemical sequence: Tryptophan becomes 5Hydroxytryptophan becomes 5Hydroxytryptamine.
• GABA is a major inhibitory neurotransmitter in the brain.
• Serotonin regulates mood, sleep, and temperature.
• Endorphins are involved in pain reduction throughout the body.
• Norepinephrine is an excitatory neurotransmitter released pre-synaptically in the sympathetic nervous system.
• Norepinephrine is responsible for the classic fight or flight response.
• Norepinephrine is a vasoconstrictor used to stop hemorrhages and allergic reactions.
• Epinephrine is a cardiac stimulant used to resuscitate the heart.
• Serotonin is the active ingredient in most antidepressants known as SSRIs (selective serotonin reuptake inhibitors).