Hypothalamic melanin-concentrating hormone projections to the septo-hippocampal complex in the rat

► The hypothalamic sources of MCH-ir/NEI-ir inputs to the hippocampal formation are the periventricular nucleus, incerto-hypothalamic area, the lateral hypothalamic area and the supramammillary nucleus. ► The MCH-ir fibers make putative synapse contact to cholinergic cells in the medial septal nucleus which in turn sends out projections to the hippocampal formation. ► The MCH-ir fibers make putative synapse contact to GABAergic basket cells in the hippocampal formation. ► We propose that there are two pathways, one direct and the other indirect from hypothalamic sites to the hippocampal formation, and these would work as the pathways subserving the food-seeking behavior.