Adrenergic Receptors Overview

Enzymes that break down monoamines, like dopamine, norepinephrine and serotonin, in the cytoplasm.

A type of drug that blocks the activity of MAO, leading to an increase in neurotransmitter levels.

A condition caused by taking MAOIs and consuming foods rich in tyramine, a substance that can trigger the release of norepinephrine, leading to high blood pressure.

A group of receptors that are activated by catecholamines (epinephrine, norepinephrine, and dopamine).

The uptake of neurotransmitters back into the presynaptic neuron, a key process in regulating neurotransmission.

Adrenergic receptors are a type of receptor that binds to the neurotransmitters noradrenaline and adrenaline (also known as norepinephrine and epinephrine). These receptors are involved in the sympathetic nervous system, which is responsible for the "fight or flight" response.

Catecholamines are a class of neurotransmitters that includes noradrenaline, adrenaline, and dopamine. They are synthesized from the amino acid tyrosine and play important roles in the sympathetic nervous system and other bodily functions.

Alpha and beta receptors are two major subtypes of adrenergic receptors. The effects of noradrenaline and adrenaline vary depending on which subtype they bind to. For example, alpha receptors are involved in vasoconstriction and beta receptors are involved in bronchodilation.

Noradrenaline and adrenaline are the main neurotransmitters that bind to adrenergic receptors. Noradrenaline is released by post-ganglionic sympathetic neurons and adrenaline is released by the adrenal medulla.

Adrenergic signaling is mediated through the release of the catecholamines noradrenaline and adrenaline. These neurotransmitters bind to adrenergic receptors leading to a cascade of downstream effects.

A type of adrenergic receptor that is coupled to Gs protein, leading to increased cAMP production and activation of protein kinase A (PKA).

β1 adrenoceptors are primarily found in the heart and kidneys, where they stimulate increased heart rate (chronotropy) and force of contraction (inotropy).

β2 adrenoceptors are expressed in smooth muscle, liver, and skeletal muscle. They cause relaxation of smooth muscle and promote glycogen breakdown in the liver.

β3 adrenoceptors are specifically found in adipose tissue and stimulate lipolysis, the breakdown of lipids into triglycerides.

Presynaptic α2 receptors act as a negative feedback mechanism to control the release of neurotransmitters. By binding to these receptors, neurotransmitters can inhibit their own release, preventing excessive activity.

One example of a neurotransmitter whose receptors are categorized by numbers and subtypes like 5-HT1, 5-HT2, 5-HT3, etc. Each type exhibits distinct signaling mechanisms and responses.

A type of serotonin receptor that activates the G protein, Gi/Go. This activation leads to a decrease in cAMP levels, resulting in an inhibitory response.

A type of serotonin receptor that activates Gq. This activation leads to an increase in IP3 and DAG, ultimately triggering a cascade of events that cause an excitatory response.

A type of serotonin receptor that is a ligand-gated ion channel. When activated, it allows sodium and potassium ions to flow across the membrane, leading to a rapid depolarization and an excitatory response.

A type of serotonin receptor that activates Gs. This activation leads to an increase in cAMP levels, resulting in an excitatory response.

A type of serotonin receptor that activates Gs. This activation leads to an increase in cAMP levels, resulting in an excitatory response.

A type of serotonin receptor that activates Gs. This activation leads to an increase in cAMP levels, resulting in an excitatory response.

A class of drugs that primarily target serotonin receptors and are commonly used in the treatment of depression.

Dopamine receptors are a type of G protein-coupled receptor (GPCR) that are primarily found in the central nervous system (CNS) and play a critical role in various functions, including motivation, pleasure, memory, and fine motor control.

D1-like receptors are a subtype of dopamine receptors that are coupled to the stimulatory G protein, Gs. These receptors activate adenylyl cyclase, leading to an increase in cAMP levels within the cell.

D2-like receptors are another subtype of dopamine receptors, but unlike D1-like receptors, they are coupled to the inhibitory G protein, Gi. This coupling inhibits adenylyl cyclase, leading to a decrease in cAMP levels.

Abnormal dopaminergic function (including malfunctions in dopamine receptors) is linked to several neuropsychiatric disorders. These disorders include Parkinson's disease, where dopamine levels are reduced, and schizophrenia, where there's an imbalance in dopamine signaling.

Purine receptors, also known as purinoceptors, are a diverse family of receptors that are activated by purines, such as adenosine, ATP, ADP, and AMP.

P1 receptors are a type of purine receptor that is specifically activated by adenosine. These receptors are GPCRs and are involved in various functions, including regulating blood flow and neurotransmission in the brain.

P2Y receptors are another type of purine receptor that are activated by a range of nucleotides, including ATP, ADP, UTP, and UDP. They are also GPCRs and play roles in processes such as platelet aggregation, smooth muscle contraction, and inflammation.

P2X receptors are unique among purine receptors because they are ligand-gated ion channels. This means they directly open up ion channels when ATP binds to them, allowing ions like calcium to flow into the cell. These receptors contribute to a wide range of functions, including neuronal excitability and neurotransmitter release.

GABA (Gamma-Aminobutyric Acid) is the main inhibitory neurotransmitter in the mammalian central nervous system (CNS). It regulates neuronal excitability, causing hyperpolarization of neurons by increasing the influx of chloride ions (Cl-) through the GABA_A receptor - a ligand-gated chloride ion channel.

GABA_A receptors are ligand-gated ion channels that open when GABA binds to them, allowing chloride ions (Cl-) to flow into the neuron, making it more negatively charged and less likely to fire an action potential.

Benzodiazepines (BDZs), like Diazepam (Valium), are a group of drugs that enhance (augment) the effects of GABA by binding to the GABA_A receptor and acting as positive allosteric modulators (PAM). This means they need GABA to be present to work.

5-HT, or serotonin, is a monoamine neurotransmitter synthesized from tryptophan in serotonergic neurons. It plays a role in various functions like mood, sleep, and cognition.

Serotonin (5-HT) is transported into synaptic vesicles by VMAT, re-uptaken into the presynaptic neuron, and broken down by MAO (monoamine oxidase). It also has pre-synaptic autoreceptor inhibition.

Serotonin (5-HT) affects various functions in the mammalian nervous system including mood, sleep, pain perception, cognition, motivation, and reward. Additionally, it plays a role in physiological processes like neuroendocrine function, vasoconstriction, and gastrointestinal motility.

The 5-HT receptor family consists of many subtypes with different functions and locations in the body. They are involved in various processes mediated by serotonin, including the regulation of mood, sleep, and appetite.

5-hydroxytryptamine (5-HT) is the chemical name for serotonin, a neurotransmitter that plays important roles in the brain and body.