CNS Drugs ETC - Pharmacology

Barbiturates in high doses can activate GABA receptors without the presence of GABA. This means that barbiturates can directly bind to GABA receptors and stimulate their activity, leading to an increase in chloride ion influx into the cell. This activation of GABA receptors by barbiturates can result in sedative, hypnotic, and anesthetic effects. It is important to note that GABA is an inhibitory neurotransmitter, so the activation of GABA receptors by barbiturates ultimately leads to a decrease in neuronal excitability, causing sedation and relaxation.

Tricyclic antidepressants are used to treat endogenous depression. Endogenous depression refers to a type of depression that is believed to be caused by internal factors such as genetics or biochemical imbalances in the brain. Tricyclic antidepressants work by increasing the levels of certain chemicals in the brain, such as serotonin and norepinephrine, which can help improve mood and alleviate symptoms of depression. Therefore, they are specifically prescribed for the treatment of endogenous depression.

The correct answer is b, c, e. This means that the statements "Plaques = extracellular deposits of beta-amyloid protein", "Bupropion increases dopamine levels", and "MAOIs take a long time to produce an effect because it takes time for changes to result from increased MAO levels (such as the production of BDNFs)" are all correct.

The correct answer is "a and e". This means that both statements "Clonidine helps with autonomic symptoms of withdrawal (from opioids, sedatives)" and "Benzodiazepines are used to treat ethanol withdrawal" are correct. Clonidine is commonly used to alleviate symptoms such as anxiety, sweating, and high blood pressure during opioid or sedative withdrawal. Benzodiazepines, on the other hand, are frequently prescribed to manage the symptoms of alcohol withdrawal.

Glutamate is a neurotransmitter that plays a role in excitatory signaling in the brain. It binds to NMDA channels, leading to the opening of ion channels and the efflux of Na+ and Ca2+ ions, as well as the influx of K+ ions. Glutamate hypofunction, or a decrease in glutamate activity, is associated with negative symptoms of psychosis. This means that when there is a decrease in glutamate function, it can contribute to symptoms such as reduced motivation, social withdrawal, and cognitive impairments. Additionally, it is mentioned that smoking marijuana can lead to increased glutamate release, which further supports the role of glutamate in excitatory signaling.

Tricyclic antidepressants, phenobarbital, heroin, and ethanol all cause CNS depression. CNS depression refers to a decrease in brain activity, leading to slowed reflexes, diminished cognitive function, and potentially unconsciousness. Tricyclic antidepressants are known to have sedative effects and can depress the central nervous system. Phenobarbital is a barbiturate that acts as a central nervous system depressant, causing sedation and sleepiness. Heroin is an opioid drug that also depresses the central nervous system, leading to drowsiness, respiratory depression, and potential overdose. Ethanol, commonly found in alcoholic beverages, is a well-known central nervous system depressant that can cause sedation, impaired coordination, and decreased cognitive function.

The correct answer is Nigostriatal. The dopamine pathway associated with movement is called the nigrostriatal pathway. This pathway originates in the substantia nigra, a region in the midbrain, and projects to the striatum, a part of the basal ganglia. It plays a crucial role in regulating voluntary movements and is involved in conditions such as Parkinson's disease, where there is a loss of dopamine-producing cells in the substantia nigra.

Dopamine has a role in inhibition, as D2 receptors bound presynaptically by dopamine cause a decrease in Ca2+ levels, leading to a decrease in dopamine release. This decrease in dopamine in the limbic system is associated with positive symptoms. Antipsychotics that block D2 receptors can cause Parkinson's like symptoms because they interfere with dopamine transmission. Therefore, the correct answer is that the role of dopamine is inhibition and D2 receptors bound presynaptically by dopamine cause decreased Ca2+, which decreases dopamine release. Additionally, antipsychotics that block D2 receptors can cause Parkinson's like symptoms.

Lithium causes a decrease in IP3 and DAG: This statement is correct because lithium is known to inhibit the enzyme inositol monophosphatase, which leads to a decrease in the production of IP3 and DAG, both of which are important second messengers involved in signal transduction pathways.

Serotonin Syndrome = seizures, cardiovascular instability, hyperthermia and severe muscular rigidity: This statement is correct because serotonin syndrome is a potentially life-threatening condition that can occur when there is an excess of serotonin in the central nervous system. It is characterized by a combination of symptoms including seizures, cardiovascular instability (such as high blood pressure and rapid heart rate), hyperthermia (elevated body temperature), and severe muscular rigidity.

Olazapine blocks muscarinic receptors which results in atropine-like symptoms: This statement is correct because olanzapine is an atypical antipsychotic medication that blocks muscarinic receptors, leading to anticholinergic effects. Atropine is a known muscarinic receptor antagonist, and the symptoms caused by olanzapine blocking these receptors can be similar to those seen with atropine use, such as dry mouth, blurred vision, constipation, and urinary retention.