Editing Pharmacology (section)

===Systems, receptors and ligands===
{{Expand section|date=July 2019}}{{Main|Ligand (biochemistry)|List of drugs|Neurotransmitter}}
[[File:Cholinergic synapse.svg|class=skin-invert-image|thumb|300px|The [[acetylcholine|cholinergic]] synapse. Targets in synapses can be modulated with pharmacological agents. In this case, [[cholinergic]]s (such as [[muscarine]]) and [[anticholinergic]]s (such as [[atropine]]) target receptors; [[Reuptake modulator|transporter inhibitors]] (such as [[hemicholinium]]) target membrane transport proteins and [[anticholinesterase]]s (such as [[sarin]]) target enzymes.]]

Pharmacology is typically studied with respect to particular systems, for example endogenous [[neurotransmitter systems]]. The major systems studied in pharmacology can be categorised by their [[ligand (biochemistry)|ligand]]s and include [[acetylcholine]], [[adrenaline]], [[glutamate]], [[GABA]], [[dopamine]], [[histamine]], [[serotonin]], [[cannabinoid]] and [[opioid]].

Molecular targets in pharmacology include [[receptor (biochemistry)|receptor]]s, [[enzyme]]s and [[membrane transport protein]]s. Enzymes can be targeted with [[enzyme inhibitors]]. Receptors are typically categorised based on structure and function. Major receptor types studied in pharmacology include [[G protein coupled receptors]], [[ligand gated ion channels]] and [[receptor tyrosine kinases]].

Network pharmacology is a subfield of pharmacology that combines principles from pharmacology, systems biology, and network analysis to study the complex interactions between drugs and targets (e.g., receptors or enzymes etc.) in biological systems. The topology of a biochemical reaction network determines the shape of drug [[dose-response relationship|dose-response curve]]<ref>{{cite journal |last1=van Wijk |first1=Roeland |last2=Tans |first2=Sander J. |last3=Wolde |first3=Pieter Rein ten |last4=Mashaghi |first4=Alireza |title=Non-monotonic dynamics and crosstalk in signaling pathways and their implications for pharmacology |journal=Scientific Reports |date=18 June 2015 |volume=5 |issue=1 |page=11376 |doi=10.1038/srep11376 |pmid=26087464 |pmc=5155565 |bibcode=2015NatSR...511376V }}</ref> as well as the type of drug-drug interactions,<ref name="Mehrad Babaei 2023">{{cite journal |last1=Babaei |first1=Mehrad |last2=Evers |first2=Tom M.J. |last3=Shokri |first3=Fereshteh |last4=Altucci |first4=Lucia |last5=de Lange |first5=Elizabeth C.M. |last6=Mashaghi |first6=Alireza |title=Biochemical reaction network topology defines dose-dependent Drug–Drug interactions |journal=Computers in Biology and Medicine |date=March 2023 |volume=155 |pages=106584 |doi=10.1016/j.compbiomed.2023.106584 |pmid=36805215 |hdl=1887/3632248 |hdl-access=free }}</ref> thus can help designing efficient and safe therapeutic strategies. The topology Network pharmacology utilizes computational tools and network analysis algorithms to identify drug targets, predict drug-drug interactions, elucidate signaling pathways, and explore the polypharmacology of drugs.