Anatomical connections of the periaqueductal gray: specific neural substrates for different kinds of fear. D.M.L. Vianna and M.L. Brandão. Brazilian Journal of Medical and Biological Research, 36 (5): 557, 2003.

Figure 3. Main connections between hypothalamic behavioral defense nuclei and periaqueductal gray (PAG). The thickness of the arrows indicates the relative density of the projections. AHN, anterior hypothalamic nucleus; dlPAG, dmPAG, lPAG and vlPAG, dorsolateral, dorsomedial, lateral and ventrolateral PAG subdivisions, respectively; PMd, dorsal premammillary nucleus; VMH, ventromedial hypothalamus.