Neurotransmitters and Neuropharmacology

Flashcards covering key concepts in neurotransmitters and neuropharmacology from the lecture notes.

What is the primary function of most synapses?

To communicate information via transmitters from the presynaptic neuron to the postsynaptic cell.

What are the major families of neurotransmitters?

Quaternary amine acetylcholine, monoamines, amino acid transmitters, neuropeptides, and gases.

What steps in synaptic transmission are potential targets for neuropharmacological compounds?

Every step, from synthesis to axonal transport to postsynaptic effects.

When a brain receptor for an exogenous drug is discovered, what does its existence imply?

That the brain makes an endogenous ligand for that receptor.

What factors influence the bioavailability of drugs?

Route of administration, biotransformation, pharmacokinetics, dose-response curves, and the ability to cross the blood-brain barrier.

What are the two main types of tolerance that can develop with repeated drug use?

Metabolic tolerance (efficient drug clearing by organ systems) and functional tolerance (up- or down-regulation of synaptic receptor density).

How can drugs affect presynaptic function?

By altering transmitter production (synthesis, transport, storage), release (axon potential propagation, transmitter release, autoreceptors), or clearance (reuptake, degradation).

What are some ways drugs can affect postsynaptic function?

Activating or blocking postsynaptic receptors, altering second messenger activity, altering gene expression, and up- or down-regulating postsynaptic receptor density.

How did first-generation antipsychotics primarily function, and how do second-generation antipsychotics differ?

First-generation antipsychotics selectively blocked dopamine D2 receptors, while second-generation antipsychotics exhibit both dopaminergic and nondopaminergic actions.

How do most common treatments for affective disorders, such as tricyclic antidepressants, SSRIs, and SNRIs, work?

They increase synaptic transmission by either inhibiting reuptake or preventing enzymatic degradation of neurotransmitters.

What are enkephalins and endorphins, and what properties do they share with opiates like morphine?

They are endogenous peptides that bind to opiate receptors and have morphine-like analgesic properties.

How does nicotine primarily act in the brain and what widespread effects does it have?

It binds to acetylcholine nicotinic receptors in the periphery and CNS, enhancing cognitive performance and activating reward pathways.

Describe the biphasic psychoactive effect of alcohol on the nervous system and the reversibility of chronic abuse effects.

An initial stimulant phase is followed by a prolonged depressant phase; many chronic effects on brain function and structure are reversible after cessation of use.

What is the active ingredient in cannabis, and what endogenous compound mediates its physiological and psychological effects?

Delta-9-tetrahydrocannabinol (THC) is the active ingredient, and endocannabinoid anandamide produces effects like improved mood, pain relief, and lowered blood pressure.

Compare the mechanisms of action for stimulants like nicotine, amphetamine, and cocaine.

Nicotine imitates excitatory transmitters; amphetamine causes release of excitatory transmitters and blocks reuptake; cocaine causes synaptic accumulation, especially of dopamine.

How do hallucinogenic drugs primarily affect perception, and what common receptor do many target?

They alter or distort existing sensory perceptions and often act as serotonin receptor agonists or partial agonists, especially at 5-HT2A receptors.

Which model of drug abuse emphasizes the activation of a dopamine-containing reward mechanism in the basal forebrain?

The positive reward model.

What has the increased understanding of the neurophysiological bases of drug abuse led to?

Proposals for several pharmacological interventions for the treatment of substance-related disorders.