Inferred network

R(Retina) → MPN(Medial preoptic nucleus)
MPN(Medial preoptic nucleus) → PAG(Periaqueductal gray)
PAG(Periaqueductal gray) → SNc(Substantia nigra compact part)
SNc(Substantia nigra compact part) → LHA(Lateral hypothalamic area)

Support information about direct projections from Retina to Medial preoptic nucleus:
Sending structure Receiving structureStrength of projection Type of connectionTechniqueGeneral descriptionCollatorAssociated reference
RetinaMedial preoptic nucleus light/moderatenot knownCholera toxin conjugated to HRP
Case pg348,349, fig5a-f. Soma notes 36 female Sprague-Dawley rats weighing 200-350g. 10 microliters of CT-HRP(.20%-.40%) were injected into one eye ?behind the lens into the vitreous chamber of the eye. pressure injection over 1 min. Terminal notes Medial component of the RHT included labeled fibres and terminals found near the midline involved the medial half of the medial preoptic area terminals evident in the ventral part of the medial preoptic nucleus.
 Levine JD, Weiss ML, Rosenwasser AM, Miselis RR., 1991

Support information about direct projections from Medial preoptic nucleus to Periaqueductal gray:
Sending structure Receiving structureStrength of projection Type of connectionTechniqueGeneral descriptionCollatorAssociated reference
Medial preoptic nucleusPeriaqueductal gray lightnot knownHRP/WGA
Case table1. Soma notes periventricular grey. Terminal notes WGA-HRP inj.
 Chiba T, Murata Y., 1985
Medial preoptic nucleusPeriaqueductal gray existsnot knownPHAL
Collator note: repeats not included from Swanson, Mogenson, Gerfen, & Robinson Brain Res. 295:161-178, 1984
 Swanson L.W., Mogenson G.J., Simerly R.B., Wu M., 1987

Support information about direct projections from Periaqueductal gray to Substantia nigra compact part:
Sending structure Receiving structureStrength of projection Type of connectionTechniqueGeneral descriptionCollatorAssociated reference
Periaqueductal graySubstantia nigra compact part moderatenot knownHRP
Case pg109, table1, fig1. Soma notes In addition moderate bilateral label is observed in the VTRZ, the nucleus parabrachialis pigmentosus and paranigralis and the compact part of the substantia nigra. Terminal notes The supraoculomotor portion of the periaqueductal gray, has been injected (HRP) in 3 rabbits & 1 rat. In all 4 cases the supraocmot/PAG has been successfully injected with minimal spread to the adjacent occulomotor nucleus..
 Giolli RA, Blanks RH, Torigoe Y, Williams DD., 1985

Support information about direct projections from Substantia nigra compact part to Lateral hypothalamic area:
Sending structure Receiving structureStrength of projection Type of connectionTechniqueGeneral descriptionCollatorAssociated reference
Substantia nigra compact partLateral hypothalamic area existsnot knownautoradiography
Case pg200, fig4. Soma notes 3H A.A. inj into medial part, slight involvement of SNr/VTA. Terminal notes not specified..
 Beckstead RM, Domesick VB, Nauta WJ., 1979