Glutamate 

(synthesis, storage, release, reuptake, receptors)

• Obtained through the diet
• Transported into vesicles by vGLuT, release and uptake by glial cell Glu channel, converted into glutamine by glutamine synthase, released to presynaptic neuron where it is converted back into glutamate by glutaminase
• Receptors - AMPA and kainate (inotropic, excitatory), NMDA (ionotropic, voltage gated), mGluR-I (G_q), MGluR-II/III (G_i)

GABA

 (synthesis, storage, release, reuptake, receptors)

• Synthesised from glutamate by glutamate decarboxylase (GAD)
• Packaged into vesicles by vesicular GABA transporter, release and uptake by GAT1/2/3 on glial cell (and presynaptic terminal), conversion to glumate by GABA-T, then glutamine by glutamine synthase, transport pack to presynapic neuron and conversion to glutamate by glutaminase, then GABA by GAD.
• Receptors - GABA_A - ligand gated ion channel to allow chloride entry and hyperpolarisation. GABA_B - G protein coupled, facilitate the opening of potassium channels, reduce AC activity

Glycine

(synthesis, storage, release, reuptake, receptors)

• Biosynthesised from serine
• Packaged into vesicles by VGAT (same transporter as GABA), released and taken up by GlyT on astrocytes and presynaptic terminals, packaged again into vesicles or converted to serine
• Acts on ligand gated ion channels to allow chloride entry (in spinal cord) as well as on NMDA receptors as a co-agonist

Monoamines 

(synthesis, storage, release, reuptake)

• L-phenylalanine to L-tyrosine (AAAH), L-tyrosine to L-DOPA (AAAH), L-DOPA to dopamine (AADC), dopamine to noradrenaline (DBH), noradrenaline to adrenaline (PNMT)
• Moved into vesicles by VMAT, release, degradation by COMT and MAO
• Transfer back into synapses by DAT, NET, SERT

• Alertness, arousal and readiness for action
• Cell group A1 in caudal ventrolateral medulla, A2 in solitary nucleus, A5 and A7 to project to spinal cord
• Most important group - A6 - locus coeruleus - projects to every major part of brain and spinal cord
• CNS adrenergic receptors - α₂ (G_i coupled)

• Production and release of dopamine from the VTA (projection to prefrontal cortex via mesocortical pathway and nucleus accumbens via mesolimbic pathway - reward and motivation) and SNc (project to dorsal striatum via nigrostriatal pathway - motor function and new motor skill acquisition)
• D_1/5 - G_s, D_2/3/4 - G_i, TAAR - G_q/s

• Rostral group - causal linear nuclei, dorsal raphe nuclei, median raphe nuclei to project to (sub)cortical structures
• Caudal group - nucleus raphe magnus, raphe obscurus nucleus, raphe pallidus nucleus and lateral medullary reticular formation to project to spinal cord - pain regulation 
• 5-HT₁ family are G_i/0- _1A (memory, learning, analgesia, aggression, dopamine release) and _1B/D vasocontriction in PNS
• 5-HT₂ family are G_q - _2A - psychedelia, depression, anxiety, NAd release from nucleus coeruleus, prefrontal glutamate release

Acetylcholine

(synthesis, storage, release, reuptake, receptors)

• Synthesis from acetyl CoA and choline by ChAT
• Packaged into vesicles by VAChT, breakdown in synapse by AchE, choline taken up by ChT
• Nuclei - pedunculopontine nucleus and laterodorsal tegmental nucleus 
• Action on M₁ receptors (G_q) on brainstem, cerebellar nuclei, pontine nuclei, locus coeruleus, raphe nucleus, reticular nucleus and inferior olive, as well as projecting to thalamus, tectum, basal ganglia, basal forebrain, neocortex and hippocampus - thought to play a role in alertness, sustaining attention and in learning and memory