U6.1 INTRODUCTION TO CNS DRUGS Flashcards
T/F Nearly all drugs with CNS effects act on specific receptors that modulate transmission.
T
T/F CNS drugs are among the most important tools for studying all aspects of CNS physiology.
T
T/F Unraveling the actions of drugs with known clinical efficacy led to the hypotheses regarding the mechanism of disease.
T
Organization of the CNS
The CNS is composed of the ____ nd _____ and is responsible for integrating sensory information and generating motor output and other behaviors needed to successfully interact with the environment and enhance species survival.
brain and spinal cord
Organization of the CNS
Electrically excitable cells that process and transmit information via an electrochemical process.
Neurons
Organization of the CNS
Large number of non-neuronal support cells, called glia, that perform a variety of essential functions in the CNS.
Neuroglia
Organization of the CNS
A protective functional separation of the
circulating blood from the extracellular fluid of the CNS that limits the penetration of substances, including drugs.
Blood-Brain Barrier
Organization of the CNS : Neurons
receive and integrate the input from other neurons and conduct this information to the cell body.
Dendrite
Organization of the CNS : Neurons
carry the output signal of a neuron from the cell body, sometimes over long distances
Axons
Organization of the CNS : Neurons
makes contact with other neurons at specialized junctions called synapses where neurotransmitter chemicals are released that interact with receptors on other neurons
Axon terminal
Organization of the CNS : Neuroglia
most abundant cell in the brain and play homeostatic support roles
Astrocytes
Organization of the CNS : Neuroglia
cells that wrap around the axons of projection neurons in the CNS forming the myelin sheath
Oligodendrocytes
Organization of the CNS : Neuroglia
specialized macrophages derived from the bone marrow that settle in the CNS and are the major immune defense system in the brain
Microglia
Sodium Channel
Blocks channel from outside
Tetrodotoxin (TTX)
Sodium Channel
Slows inactivation, shifts activation
Batrachotoxoin (BTX)
Potassium channels
Blocks “small Ca-activated” K channel
Apamin
Potassium channels
Blocks “big Ca-activated” K channel
Charybdotoxin
Calcium channels
Blocks N-type channel
Omega conotoxin (ω-CTX-GVIA)
Calcium channels
Blocks P-type channel
Agatoxin (ω-AGAIVA)
Ligand-gated channel
Irreversible antagonist
α-Bungarotoxin
Ligand-gated channel
Blocks channel
Picrotoxin
Ligand-gated channel
Competitive antagonist
Strychnine
Ligand-gated channel
Blocks channel
Philanthotoxin
Ion Channel
Tetrodotoxin (TTX), Batrachotoxoin (BTX)
Voltage-gated, Sodium
Ion Channel
Apamin, Charybdotoxin
Voltage-gated, Potassium
Ion Channel
Omega conotoxin (ω-CTX-GVIA), Agatoxin (ω-AGAIVA)
Voltage-gated, Calcium
Ion Channel
α-Bungarotoxin
Ligand-gated, Nicotinic Ach receptor
Ion Channel
Picrotoxin
Ligand-gated, GABAA receptor
Ion Channel
Strychnine
Ligand-gated, Glycine
Ion Channel
Philanthotoxin
Ligand-gated, AMPA
The nerve cells contain two types of channels defined on the basis of the mechanism controlling their gating (opening and closing) :
- Voltage-gated channels
- Ligand-gated channels
Ion Channels
Responds to changes in membrane potential
Voltage-gated Ion Channels
Ion Channels
Concentrated on the initial segment of the axons in
nerve cells.
Voltage-gated Ion Channels