Neurotransmission, Receptors, and Pharmacology – Lecture Notes

Vocabulary flashcards covering key concepts, transporters, receptors, pathways, and modulators from the lecture notes.

VMAT2

Vesicular monoamine transporter 2; packages monoamines (serotonin, norepinephrine, dopamine, histamine) into vesicles for release; primary vesicular transporter of interest in psychiatry.

Vesicular monoamine transporter (VMAT)

Packaging transporter that loads neurotransmitters into vesicles for release; VMAT2 is the main subtype in psychiatry.

Monoamines

Serotonin (5-HT), norepinephrine (NE), dopamine (DA), and histamine—the neurotransmitters packaged into vesicles and released in monoaminergic signaling.

SERT

Serotonin transporter; reuptake transporter for serotonin; substrate for MDMA; major target of SSRIs.

NET

Norepinephrine transporter; reuptake transporter for NE (can also transport dopamine due to similarity); relevant for ADHD medications.

DAT

Dopamine transporter; reuptake transporter for dopamine (and to some extent epinephrine); key target of many psychotropic medications.

MDMA

Ecstasy; acts as a substrate for SERT, NET, and DAT, causing massive release of monoamines.

SSRIs

Selective serotonin reuptake inhibitors; block SERT to elevate serotonin in the synaptic cleft.

MAO

Monoamine oxidase; enzyme that degrades monoamines; MAO inhibitors prolong monoamine signaling.

COMT

Catechol-O-methyltransferase; degrades catecholamines (e.g., dopamine); COMT inhibitors prolong monoamine action.

Monoamine reuptake transporters

SERT, NET, and DAT; reuptake monoamines from the synaptic cleft; primary targets of many antidepressants.

Ionotropic receptors

Ligand-gated ion channels; fast signaling by direct ion flux.

Metabotropic receptors

G-protein coupled receptors (GPCRs); slower signaling via second messengers.

First messenger

The neurotransmitter or ligand binding to a receptor to initiate signaling.

Second messenger

Intracellular signaling molecules (e.g., cAMP, IP3, DAG) activated by receptor signaling.

Third messenger

Downstream signaling elements that propagate signals within the cell.

Fourth messenger

Changes such as gene expression that lead to long-term cellular effects; e.g., lithium acts downstream.

Autoreceptors

Presynaptic receptors that regulate transmitter release and firing rate; provide negative feedback.

NMDA receptor

Glutamate receptor involved in synaptic plasticity; dysfunction linked to schizophrenia; targeted by ketamine.

Ketamine

NMDA receptor modulator with rapid-acting antidepressant effects via glutamatergic signaling.

GABA-A receptor

Ionotropic GABA receptor; benzodiazepines are positive allosteric modulators increasing inhibition.

GABA-B receptor

Metabotropic GABA receptor involved in slower inhibitory signaling.

Benzodiazepines

Positive allosteric modulators of GABA-A receptors; anxiolytic/sedative effects; risk of dependence with use.

5-HT1A

Serotonin receptor subtype; often inhibitory autoreceptor in some brain regions; affects mood and anxiety.

5-HT1B

Serotonin receptor subtype; involved in anxiety/depression; modulates drug effects.

5-HT2A

Serotonin receptor; target of many antipsychotics; modulates dopamine signaling and cognition; linked to antidepressant effects and side effects.

5-HT2C

Serotonin receptor; important for mood regulation; targeted to modulate norepinephrine/dopamine with fewer side effects.

5-HT3

Ionotropic serotonin receptor; linked to nausea, emesis, and certain anxiety pathways.

5-HT7

Serotonin receptor implicated in circadian rhythms and mood regulation.

Dopamine receptors D1–D5

Five receptor families; D2 blockade is central to many antipsychotics; D1–D5 have roles in cognition, mood, and motivation.

Nigrostriatal pathway

Dopamine pathway involved in movement and motor control; one of the major dopamine circuits.

Mesolimbic pathway

Dopamine pathway linked to reward and psychosis; target in antipsychotic therapy.

Mesocortical pathway

Dopamine pathway related to cognition and mood regulation; implicated in negative symptoms of schizophrenia.

Tuberoinfundibular pathway

Dopamine pathway regulating prolactin release; interacts with endocrine functions.

Acetylcholine (ACh)

Neurotransmitter involved in learning and memory; interacts with dopamine; implicated in dementia and schizophrenia-related processes.

Orexin

Hypothalamic system regulating wakefulness and arousal; orexin antagonists for insomnia; agonists for narcolepsy.

Endocannabinoids

Endogenous lipid neuromodulators involved in pain, appetite, anxiety; widespread roles in mood and pain.

Histamine receptors H1–H4

Histamine receptor subtypes with roles in arousal (H1), gastric signaling (H2), and other CNS functions (H3, H4).

Muscarinic receptors (M1–M5)

Acetylcholine receptors involved in cognition and memory; M4 modulates dopamine release; relevant to schizophrenia.

Gut–brain axis

Connectivity between gut signals and brain; 5-HT receptors are distributed in brain and gut; linked to mood and GI symptoms.