Neurotransmitters Ch. 8, 9

Practice flashcards covering neurotransmitter types, receptor functions, synthesis pathways, and the impacts of various substances of abuse as detailed in the lecture recordings.

What term is used to describe any substance that binds to a receptor?

A ligand

What is a ligand called if it binds to a receptor and produces a similar response to the endogenous ligand?

Receptor agonist

How do competitive antagonists function at a receptor?

They block responses by competing for the same binding site as the agonist.

What is the role of a noncompetitive ligand, also known as a neuromodulator?

It binds to a modulatory site to alter the receptor response.

Who is credited with discovering the first neurotransmitter, Acetylcholine, in the 1920s?

Otto Loewi

Which two molecules are used to synthesize Acetylcholine in nerve terminals?

Choline and acetyl CoA

What are the two main types of cholinergic receptors?

Nicotinic (ionotropic) and muscarinic (metabotropic)

Which neurotransmitter is identified as the most abundant excitatory neurotransmitter in the CNS?

Glutamate

Through which local precursor is Glutamate synthesized in neurons?

Glutamine

What are the three specific types of ionotropic glutamatergic receptors?

NMDA, AMPA, and kainate

Dysregulation of which glutamatergic receptor type is associated with Fragile X/autism and Schizophrenia?

mGluR

What is the most abundant inhibitory neurotransmitter in the Central Nervous System?

GABA ($\gamma$-aminobutyric acid)

Through which ion channels do GABAA and GABAC receptors typically operate?

$Cl^-$ channels

From which amino acid is the inhibitory neurotransmitter Glycine synthesized?

Serine

Which three neurotransmitters are categorized as Catecholamines?

Dopamine, norepinephrine, and epinephrine

What is the main brain area associated with the excitatory neurotransmitter Dopamine?

Corpus striatum

Which amino acid serves as the derivative for Dopamine synthesis?

Tyrosine

What is the main brain area for Norepinephrine, also known as noradrenaline?

Locus coeruleus

Which neurotransmitter is a derivative of norepinephrine and functions in respiration and cardiac function?

Epinephrine (adrenaline)

Where is the main area for Serotonin (5-HT) production in the brain?

The raphe of pons and upper brainstem

From which amino acid is Serotonin derived?

Tryptophan

What is the target for SSRIs in the serotonergic system?

SERTs (specific serotonin transporters)

Which excitatory neurotransmitter is a derivative of histidine and functions in arousal and attention?

Histamine

Where are neuropeptides synthesized within the cell?

In the cell body (Rough ER)

What is one of the most abundant neuropeptides, which acts as a vasoconstrictor in the PNS?

NPY (Neuropeptide Y)

What are the three main classes of endogenous opioids produced by neurons?

Endorphins, enkephalins, and dynorphins

Which receptors were originally discovered as the targets of $\Delta^9$-tetrahydrocannabinol?

Endogenous cannabinoid receptors

Which endocannabinoid is associated with appetite, immune system functions, and pain management?

2-arachidonoylglycerol (2-AG)

What enzyme is responsible for removing endocannabinoids from the synapse via reuptake into the postsynaptic cell?

FAAH

Why is Nitric Oxide (NO) considered an unconventional retrograde neurotransmitter?

It is a gas, it is not stored in vesicles, and it has no receptors.

Which brain circuit is responsible for learning associated with reward and is hijacked by psychoactive drugs?

Dopamine reward system

Which specific ionotropic channel does alcohol activate to cause postsynaptic inhibition?

GABAA ionotropic $Cl^-$ channel

According to the lecture, what percentage of nAChR in the body are bound by the nicotine from a single cigarette?

$$88\%$$

How does cocaine increase the amount of Dopamine in the synapse?

By blocking reuptake

Which synthetic stimulants resemble dopamine and norepinephrine and can treat ADHD or narcolepsy?

Amphetamines

Which group of drugs distorts senses and adds to the effects of serotonin, norepinephrine, or ACh?

Hallucinogens (or psychedelics)

What plant is the source of natural opiates like codeine and morphine?

Papaver somniferum (opium poppy)

What percentage of heroin use is estimated to stem from nonmedical prescription opioid addiction?

$$86\%$$

What medication is used as an emergency nasal spray or injection to reverse an opioid overdose?

Naloxone (Kloxxado, Narcan, or Zimhi)

Which medication is a daily liquid used as an opioid receptor agonist to reduce opioid use and cravings?

Methadone (Dolophine, Methadose)