Summary of our current understanding of the neuron types in the VMH. Several lines of evidence indicate that the ERα-containing neurons are largely separate from the PAG-projecting neurons. Various markers have been co-localized with the ERα-containing neurons. The available evidence suggests that there is a third cell type, that is, non-ERα-containing neurons and non-PAG-projecting neurons. Although several features may be attributed to these neurons, it is not yet known if this represents a single cell type. Abbreviations: Enkephalin, Enk; Estrogen receptor-α; ERα; Neuronal nitrous oxide synthase, nNOS; Oxytocin receptor, OTR; Vesicular glutamate transporter 2, vGlut2. References: [75; 81; 82; 83; 84; 85; 94; 102; 103; 104; 109].