Psychopharmacology: Antidepressants, GABA, and Neurotransmitter Modulation

What is the primary goal of antidepressants?

To increase serotonin levels in the synapse for emotional stability.

What is the mechanism of action for MAOIs?

They block the enzyme monoamine oxidase, preventing the breakdown of serotonin.

What are the risks associated with MAOIs?

High toxicity and potential for lethality due to tyramine buildup, especially from certain foods.

How do tricyclic antidepressants work?

They block the reuptake of serotonin, dopamine, and norepinephrine, increasing their levels in the synapse.

What is a significant risk of tricyclic antidepressants at high doses?

They can block sodium channels, preventing action potentials.

What distinguishes SSRIs from other antidepressants?

SSRIs selectively block the reuptake of serotonin, making them safer and effective.

What is the goal of anxiolytics?

To increase GABA activity and decrease overall neuronal activity.

What is the role of GABA in the nervous system?

GABA is an inhibitory neurotransmitter that reduces neuronal excitability.

What are positive allosteric modulators (PAM) in relation to GABA?

They enhance GABA's effects but require GABA to be present for action.

What are the risks associated with barbiturates?

High risk of overdose and lethality; they are less commonly used today.

What is the biphasic effect of alcohol on GABA activity?

Low doses can increase GABA activity, while higher doses produce depressant effects.

How does caffeine affect adenosine receptors?

Caffeine acts as an adenosine antagonist, blocking its effects and promoting wakefulness.

What is the mechanism of action for nicotine?

Nicotine binds to acetylcholine receptors, mimicking acetylcholine's effects.

How does cocaine affect dopamine levels?

Cocaine is a reuptake blocker for dopamine, preventing its removal from synaptic clefts.

What is the effect of amphetamines on dopamine?

Amphetamines increase dopamine release and inhibit its breakdown by occupying enzymes.

What are the effects of methamphetamine on neurotransmitters?

Methamphetamine permanently occupies enzymes that break down dopamine, increasing its levels.

What is the primary action of hallucinogens like LSD?

They act as serotonin receptor agonists, altering perception and mood.

What are the effects of MDMA (Ecstasy)?

MDMA increases heart rate, sociability, and alters perceptions, impacting serotonin and dopamine.

What is the action of PCP on glutamate receptors?

PCP acts as an NMDA receptor antagonist, increasing sympathetic nervous system activity.

What are the potential long-term effects of glutamate antagonists like PCP?

Chronic use can lead to excitotoxicity, loss of brain cells, and tissue damage.