The term incerto-hypothalamic area (IHA) refers to a poorly defined cluster of chemically-defined ( A13 group ) dopaminergic cells and melanin-concentrating hormone expressing cells (MCH) in the medial zone of the hypothalamus (MZH).at its junction with zona incerta (ZI). It projects to the reuniens nucleus, precommissural nucleus (PCM), posterior hypothalamic area and dorsolateral periaqueductal gray ( Sita-2007 ). Updated 20 Oct 2025..