Evolutionofneurotransmittergamma-aminobutyricacid,glutamateandtheirreceptors

Gamma-aminobutyricacid(GABA)andglutamatearetwoimportantaminoacidneurotransmitterswidelypresentinthenervoussystemsofmammals,insects,roundworm,andplatyhelminths,whiletheirreceptorsarequitediversifiedacrossdifferentanimalphyla.However,theevolutionarymechanismsbetweenthetwoconservedneurotransmittersandtheirdiversifiedreceptorsremainelusive,andantagonisticinteractionsbetweenGABAandglutamatesignaltransductionsystems,inparticular,havebeguntoattractsignificantattention.Inthisreview,wesummarizetheextantresultsontheoriginandevolutionofGABAandglutamate,aswellastheirreceptors,andanalyzepossibleevolutionaryprocessesandphylogeneticrelationshipsofvariousGABAsandglutamatereceptors.WefurtherdiscusstheevolutionaryhistoryofExcitatory/NeutralAminoAcidTransporter(EAAT),atransportprotein,whichplaysanimportantroleintheGABA-glutamate“yinandyang”balancedregulation.Finally,basedoncurrentadvances,weproposeseveralpotentialdirectionsoffutureresearch.