Chapter 4, The Chemistry of Behaviour Flashcards
What does Neurochemistry focus on?
The basic chemical composition and processes of the nervous system
What is Neuropharmacology?
The study of compounds that selectively affect the nervous system.
What is Neurochemistry?
The branch of neuroscience is concerned with the fundamental chemical composition and processes of the nervous system.
What is Exogenous?
Arising from outside the body.
Explain the versatility of Neurotransmitters.
May activate ionotropic receptors at some synapses.
- Different NT for different subtypes of receptor
- 14 subtypes for serotonin, 5 for Dopamine, 5 for Norepinephrine
May activate a metabotropic receptor at another synapse.
What is an Ionotropic Receptor?
Also called a Ligand-gated ion channel and chemically gated ion channel. A receptor protein includes an ion channel that is open when the receptor is bound by an agonist.
What is a Metabotropic Receptor?
A receptor protein that does not contain an ion channel but may, when activated, use a G-protein second-messenger system to alter the functioning of the postsynaptic cell.
What is a Receptor?
Also called receptor molecule. A protein that binds and reacts to molecules of a neurotransmitter or hormone.
What are the criteria for Neurotransmitters in the Presynaptic cell?
- Substance exists in presynaptic axon terminals
- Is synthesized in presynaptic cells
- Is released when action potentials reach axon terminals.
What are the criteria for Neurotransmitters in the Postsynaptic cell?
- Receptors for the substance exist on the postsynaptic membrane.
- When experimentally applied, the substance produces changes in postsynaptic cells
- Blocking substance release prevents changes in the postsynaptic cell
What are the types of Neurotransmitters (NT)?
- Amine NT = Acetylcholine, Dopamine, Serotonin, epinephrine, norepinephrine, melatonin
- Amino Acid NT = Gamma-aminobutyric acid (GABA), Glutamate, aspartate,
- Peptide NT (or neuropeptides) = Short-chain amino acids
- Gas NT = Soluble gases; nitric oxide, carbon dioxide.
What is Co-localization (co-release)?
Occurs when nerve cells contain more than one type of neurotransmitter.
A Neurotransmitter is what for a particular receptor?
An endogenous ligand
What is the name of a drug that can bind to a receptor and activate it?
A receptor agonist
Can drugs also act as agonists?
Yes, if they block reuptake or degradation of a Neurotransmitter.
What is the name of a drug that can bind to a receptor but does not activate it?
A receptor antagonist
What can Receptor Antagonists be?
It can be competitive (when they bind to the same site as the endogenous ligand)
Or they can be non-competitive or neuromodulators (when they bind to an alternate site and prevent the receptor from activating).
Can drugs interfere with synaptic transmission?
Yes, drugs can interfere with the many different processes involved in synaptic transmission.
What is Glutamate?
It is a major excitatory NT in the CNS.
- Most of the activity in the brain results from glutamate signaling.
- There are ionotropic and metabotropic glutamate receptors.
- To terminate glutamatergic synaptic transmission, glutamate is taken up by neighboring astrocytes.
What is GABA?
A major inhibitory NT in the CNS.
-Inhibition plays a very important role in brain function. GABA signaling is responsible for many of the IPSP’s generated in the brain.
What is Glutamatergic?
Referring to cells that use Glutamate as their synaptic transmitter.
What is Excitotoxicity?
The property by which neurons die when overstimulated, as with large amounts of Glutamate.
What are some of the Ionotropic Glutamate receptors?
- AMPA
- NMDA
- Kainate
The binding of glutamate to ionotropic receptors results in what?
The opening of a sodium ion channel.