P3: Neurotransmission Flashcards
What are different classes of Neurotransmitters and which one belongs to which class?
Amino acids: Glutamate, Aspartate, Glycine, GABA
Monoamines: Catecholamines: Dopamine, Epinephrine, Norepinephrine
Monoamines: Indolamines: Serotonin
Acetylcholine: Acetylcholine
Unconventional neurotransmitters: Soluble gases: Nitric oxide, Carbon monoxide
Unconventional neurotransmitters: Endocannabinoids: Anandamide
Which Neurotransmitters are small and which are large molecules?
small ones: are amino acids, monoamines, ACH, Gases and Cannabinoids
big ones are the peptides: in general: Pituitary peptides,
Hypothalamic peptides, Brain–gut peptides, Opioid peptides, NPY, AGRP, Vasopressin, Ghrelin, Oxytocin
What happens on the pre-synaptic side with Neurotransmitters?
Presynaptic Neuron/Axon Terminal/:
- Action potential coming down.
- Opens up voltage-gated Channels
- Calcium-IONs(+) move in, presynapse depolarises
- IONS dock wick chemicals on the presynaptic vesicles which activates proteins on the vesicles
- That enables the vesicles to dock on the Docking Protein at the Presynaptic side.
- Vesicles merge and dump their Neurotransmitters: Exocytosis.
What else happens with Neurotransmitters: Degradation, Reuptake, Inactivation,
What happens on the post-synaptic side with Neurotransmitters?
also called the button
- 0 Chemicals can dock with Receptors at the postsynaptic side. There are ionotropic(open up ion channel directly)and metabotropic receptors(opens up ion channels indirectly through G proteins).
- 1 There are subtypes of Neurotransmitters: for Serotonin there are 14 different subtypes of receptors with different effects. Serotonin interacts with all subtypes but drugs can be designed to interact only with one subtype to produce the specific effects.
What are second messengers?
Send internal chemical signals to affect ion-channels
Can amplify and prolong the synaptic signals. Are used in metabotropic receptors.
Wat are agonists, antagonists, and inverse agonists?
agonists: Normal effect of Neurotransmitter
Antagonists: Binds to the receptor but doesn’t activate it. It blocks the receptor from being activated by other ligands.
inverse agonists: Effect is the reverse of the normal function of the receptor. It has a negative efficacy. It exerts the opposite effect by suppressing spontaneous receptor signaling (when present)
What are retrograde transmitters?
They are diffusing from postsynaptic to presynaptic Neuron signaling the presynaptic cell to signal up - or downregulation.
What happens if what binds with Auto receptor? (agonist, antagonist)
Agonist(on the autoreceptor) would increase the release of neurotransmitters
Antagonist(on the autoreceptor) would slow down the release of neurotransmitters.
- -> so antagonist on the postsynaptic cell is an agonist on the autoreceptor(e.g.: idazoxan)
https: //www.ncbi.nlm.nih.gov/pubmed/8945740
Why do people overdose with the same amount of a drug?
Because of Conditioning and homeostatis. So in the conditioned environment e.g. home the body prepares for the intake of heroin by increasing the heart rate (conditioned responses)which compensates for the lowering of the hear rate by heroin. So it tries to keep the body on balance –> homeostasis. This homeostatic process might be triggered too late when the drug is taken in an unconditioned environment so the intake is suddenly and unexpected.
What are the effects of Alcohol in the brain?
GABA: inhibitory: is increased by Alc.
Glutamate: excitatory: is decreased by Alc.
Dopamine + Serotonin: increases release –> reward + uplift in mood
Brain Adapts: decrease of GABA + increase of Glutamate
Withdrawal: brain is hyperexcitable
What are the effects of Caffee in the brain?
Adenosine: slows down brain activity
Caffee is an Adenosine Antagonist.
Adrenaline: increased by Coffee
Dopamine: preventing reuptake of it –> increase
