Serotonin: Interactions with Dopamine
Serotonin and dopamine systems influence one another through networks rather than operating independently. Activity at particular serotonin receptors can change dopamine release or the behaviour of circuits receiving dopamine. This is relevant to antipsychotics that…Continue Reading
Serotonin: 5-HT1A Receptors
5-HT1A receptors occur in several brain systems, including as autoreceptors that influence serotonin neuron activity. Some antipsychotics, such as aripiprazole, cariprazine and lurasidone, have partial agonist activity at this receptor. Researchers investigate possible contributions to…Continue Reading
Serotonin: 5-HT2A Receptors
5-HT2A receptors are important targets of many second-generation antipsychotics. Blocking them can alter interactions between serotonin and dopamine pathways. This has been proposed as one contributor to the lower movement-related risk of some receptor profiles…Continue Reading
Serotonin: Receptor Families
Serotonin receptors are grouped into families identified as 5-HT1 through 5-HT7, with several subtypes. Most are G protein-coupled receptors; 5-HT3 is an ion channel. They differ in distribution, signalling and function. A drug’s action at…Continue Reading
Serotonin: Chemical Signalling
Serotonin signalling occurs when serotonin is released and binds to receptors on nearby cells. Its effects are regulated by synthesis, release, reuptake and metabolism. Different receptors trigger different cellular responses, so changing serotonin signalling in…Continue Reading
Dopamine Receptors: Antagonism and Partial Agonism
An agonist activates a receptor, while an antagonist prevents activation by occupying or otherwise blocking it. A partial agonist produces less activation than a full agonist under comparable conditions. At dopamine receptors, partial agonists can…Continue Reading
Dopamine Receptors: Intracellular Signalling
Intracellular signalling is the chain of events inside a cell after a receptor is activated. Dopamine receptors influence enzymes, second messengers, ion channels and proteins that regulate cellular activity. D1-like receptors generally increase cyclic AMP…Continue Reading
Dopamine Receptors: D3 and D4 Receptors
D3 and D4 are members of the D2-like receptor family. They have different distributions and pharmacological properties from D2. D3 is studied in relation to motivation and reward, while D4 has attracted interest partly because…Continue Reading
Dopamine Receptors: D2 Receptors
D2 receptors are central targets of most established antipsychotics. They usually signal through Gi/o proteins and influence cyclic AMP, ion channels and other cellular processes. They occur on receiving neurons and as autoreceptors involved in…Continue Reading
Dopamine Receptors: D1 and D5 Receptors
D1 and D5 belong to the D1-like receptor family. Their signalling generally increases cyclic AMP through Gs or Golf proteins. D1 receptors are important in prefrontal networks supporting working memory and other cognitive functions. Experimental…Continue Reading