7.2 Introduction to CNS [Yeye Edition] Flashcards
ION CHANNELS AND NEUROTRANSMITTER RECEPTORS
What are the 2 Ion Channels
- Voltage Gated
- Ligand Gated
Voltage-Gated: SODIUM channel
Affected by what 2 factors
Tetrodotoxin
Batrachotoxin
Voltage-Gated: POTASSIUM channel
Affected by what 2 factors
Apamin
Charybdotoxin
Voltage-Gated: Calcium channel
Affected by what 2 factors
Omega conotozin
Agatoxin
Voltage-Gated: SODIUM channel
_________: Blocks channel from outside, Puffer Fish
Tetrodotoxin [TTX]
Voltage-Gated: SODIUM channel
_________: Slows inactivation, shifts activation, Colombian Frog
Batrachotoxin [BTX]
Voltage-Gated: POTASSIUM channel
_________: Blocks “SMALL Ca-activated” K channel, Pacific Cone Snail
Apamin
Voltage-Gated: POTASSIUM channel
_________: Blocks “BIG Ca-activated K “channel, Funnel web spider
Charybdotoxin
Voltage-Gated: CALCIUM channel
_________: Blocks N-type channel, Pacific Cone Snail
Omega conotoxin
Voltage-Gated: CALCIUM channel
_________: Blocks P-type channel, Funnel Web spider
Agatoxin
What are the 3 Voltage Gated Channels
- Sodium
- Potassium
- Calcium
Ligand-Gated: Nicotinic ACh
Affected by what factors
Cx - Bungarotoxin
IRREVERISBLE ANTAGONIST, Marin Snake
Ligand-Gated: GABA RECEPTOR
Affected by what factors
Picrotoxin
Blocks channel, South Pacific Plant
Ligand-Gated: Glycine receptor
Affected by what factors
Strychnine
COMPETITIVE antagonist, Indian Plant
Ligand-Gated: AMPA Receptors
Affected by what factors
Philanthotoxin
Blocks channel, Wasp
Affected by several toxins such as TTX and BTX
Sodium Channels
What channel close or open depending on the charge inside and outside of the neurons
Voltage-Gated Channels
What channel requires a chemical ligand to attach to the binding site so that it will be opening or closing the gates
Ligand Gated Channel
What channel would have an opening that stimulated or inhibit the cells (neuron cells)
Ligand Gated Channels
What channel has exogenous and endogenous chemicals that can mimic the ligand to be able to open ionotropic and metabotropic channels
Ligand Gated Channels
Concentrated on the axon hillock or INITIAL SEGMENT of the axons in nerve cells as it exits the soma, the nerve cell
Voltage-Gated Ion Channel
What are the 2 classes of neurotransmitter receptors
- Ligand gated ion channel or Ionotropic Receptors
- Metabotropic Receptors
Chemically-gated, respond to chemical neurotransmitters (NTAs) that bind to receptor subunits of the channel
Ligand Gated Ion Channel
These receptors consist of multiple subunits, and binding of the neurotransmitter LIGAND directly opens the channel, which is an integral part of the receptor complex
Ionotropic Receptors
What receptor is SEVEN transmembrane G protein coupled (serpentine)
Metabotropic Receptors
Binding does not result in the direct gating of a channel
Metabotropic Receptors
True or False:
Membrane delimited pathway is the activation of metabotropic neurotransmitter receptors often leads to the modulation of voltage gated channels.
True
What are the 3 types of receptor channel coupling in LIGAND gated ion channel
- Receptors that acts DIRECTLY on the ion channel protein
- Receptors that is coupled to the ion channel through G protein
- Receptors coupled to a G protein that modulated the formation of diffusible second messengers
What are the 3 mechanism under Diffusible second messengers
- Cyclic adenosine monophosphate [cAMP]
- Ionositol triphosphate [IP3]
- Diacylglycerol [DAG]
Influx of ions whether inside or outside the cell is an electrical mechanism
Synapse
What are the 2 Synapse
Excitatory postsynaptic potentials (EPSPs)
or Inhibitory postsynaptic potentials (IPSP)
Depolarizing potential change
Excitatory postsynaptic potentials (EPSPs)
[Increase Positive, Decrease Negative]
It is positive outside and negative inside
Resting membrane
What are the 2 depolarizing change
- Opening of sodium (Na) or calcium channels (Ca)
- Closing of potassium (K) channels in some synapses
Higher Sodium [Na], Higher Calcium [Ca], Lower Potassium [K]
Excitatory postsynaptic potentials (EPSPs)
Hyperpolarizing potential change
Inhibitory postsynaptic potentials (IPSP)
[Increase Negative]
Generated by opening of potassium (K) or chloride (Cl) channels
Hyperpolarizing potential change
Higher Potassium [K], Higher Chlorine [CL] at postsynaptic, Lower Calcium [Ca] at presynaptic
Inhibitory postsynaptic potentials (IPSP)