Nervous System I Flashcards
CNS Building Blocks
Neurons (CNS drug targets) and glial cells (most abundant)
Glial cells are composed of
Astrocytes and Oligodendrocytes
Astrocytes
The most abundant cells in the brain. Support neurons (physical, nutritional, healthy environment) MLS, ALS, Repair after spinal cord injury.
Oligodendrocytes
Form the myelin sheaths wrapping around axons. Enhance the conduction of action potentials (neurological and physichiatric conditions) epilepsy.
Voltage-gated channels
located on the axon. responsible for fast action potential.
Neurotransmitter Receptors
mediate effects of neurotransmitters receiving information (postsynaptic neuron)
Ligand Gated Channels are:
Ionotropic. Direct binding directly opens the channel. Fast transmission. Example: Nicotinic (ACh Receptor)
Metabotropic Receptors are:
G-protein coupled.Binding of neurotransmitters does NOT result in the direct gating of the channel. Engages a G-protein / an additional enzyme, leading to the production of second messengers that modulate voltage-gated channels (K+ and Ca2+) – the effects last much longer
• For example, serotonin receptors
Excitatory Neurotransmitters (Glutamate aa)
Act to stimulate the firing of a postsynaptic neuron
• Lead to changes that generate an action potential in the responding neuron
Inhibitory Neurotransmitters (GABA)
Act to inhibit or block the changes that cause an action potential to be generated in the responding neuron
Glutamate- excitatory
Learning and memory (long-term potentiation; LTP)– Alzheimer’s disease
AMPA/ NMDA major receptors
Drug memantine
GABA- inhibitory
Important in producing sleep, reducing anxiety, and forming
memories
– Basal ganglia: voluntary movement and coordination– Huntington’s disease
Dopamine is in what part of the brain?
Substantia Nigra: controls movement
Parkinsons disease
What part of the brain is serotonin in?
Raphe Nucleus: mood, emotions, anxiety, aggression, and sleep
Low levels cause depression
