Term
| What are the major events that occur in GABA neurotransmission? |
|
Definition
1) GABA synthesized in neurons from glutamate by glutamic acid decarboxylase (GAD), packaged into vesicles and stored at terminals.
2) GABA binds A (ligand-gated Cl- channels), B (GPCR to K and Ca channels) and C receptor (A in the RETINA) subtypes
3) Taken up by pre-synaptic terminal and glial cells |
|
|
Term
How do drugs such as Valium, Librium, Versed and Xanax work and how are they used clinically?
Why might you want to have Flumazenil nearby as well? |
|
Definition
- Benzodiazepines such as Diazepam (VALIUM), Chorodiazepoxide (LIBRIUM), midazolam (VERSED and alprazolam (XANAX) increases GABA affinity.
**Flumazenil will competitively inhibit Benzos**
- They cause sedation, hypnosis, anterograde amnesia, muscle relaxation and protect against seizures.
-Used to treat anxiety disorders, alcohol withdrawal, epilepsy and insomnia. |
|
|
Term
| How can the diversity of GABAa-R subunits (transmembrane spanning proteins) lead to differences in pharmacology and function? |
|
Definition
Benzodiazepine-induced behavior effects are mediated by subunit composition.
1) a2 GABAa-R is important for anxiolytic effects
2) a1 GABAa-R is important for amnestic effect
Need to make subunit-specific drugs for specific effects! |
|
|
Term
How do drugs such as Brevital, Nembutal, Luminal and Pentothal work and how are they used clinically?
Why might you want to have Flumazenil nearby as well? |
|
Definition
BARBITUATES such as methohexital (Brevital), pentobarbital (Nembutal), phenobarbital (Luminal) and thiopental (Pentothal) reversibly depress neuronal activity via GABAa-R (binding and direct activation vs. indirect effects of Benzos)
- fast-acting intravenous anesthetics used to treat epilepsy, but VERY DANGEROUS if used with alcohol and can lead to dependence with continued use. |
|
|
Term
| How do general anesthetics such as Propofol and Etomidate cause anesthesia? |
|
Definition
| Potentiate effects of GABA at GABAa-R (like Benzodiazepines) with subunit specificity |
|
|
Term
| Where do Neurosteroids such as Alphaxalone act in the brain and what effects do they exert? |
|
Definition
1) Many places but most sensitive at GABAa-R
2) Anti-convulsant, sedative and anesthetic |
|
|
Term
| Where do Anti-epileptics act in the brain and what effects do they exert? |
|
Definition
Alter GABA neurotransmission
1) Benzodiazepines like Klonopin and Valium ehance GABA affinity for GABAa-R
2) Barbiturates such as Luminal bind to and activate GABAa-R
3) GABITRIL blocks GABA re-uptake by pre-synaptic terminal and glial cells. |
|
|
Term
| Why would you prescribe drugs such as Ambien, Sonata and Lunesta? |
|
Definition
These drugs are Benzo-like compounds used as sleep aids, because they bind to benzodiazepine site on alpha subunits of GABAa-R and potentiate receptor function.
TRAFFIC ACCIDENTS |
|
|
