Regulation of Nucleus Accumbens Activity by the Hypothalamic Neuropeptide Melanin-Concentrating Hormone

Lateral Hypothalamus GABAergic Neurons Modulate Consummatory Behaviors Regardless of the Caloric Content or Biological Relevance of the Consumed Stimuli

“…MCH/GABAergic neurons in the LH project to the VTA and NAc (Bittencourt et al, 1992;DallvechiaAdams et al, 2002;Saito et al, 2001;Sears et al, 2010) and modulate consumption of natural and drug rewards (Morganstern et al, 2010;Parker and Bloom, 2012). However, as we used the same vGat-ires-cre mice used by Jennings et al (2015) and the same DREADD constructs, MCH/GABAergic neurons are unlikely to be involved as cre is not present in MCH neurons of the current vGat-ires-cre mice (Jennings et al, 2015).…”

Different distributions of preproMCH and hypocretin/orexin in the forebrain of the pig (Sus scrofa domesticus)

“…They project through the mfb in the rodent LHA. With regard to the very abundant MCH projections in these structures in the pig, it is possible that pig MCH neurons are especially involved in mediating these responses in amygdalar sites, while it has been shown that in rodent, MCH influence feeding by interacting with its receptor MCHR1 in the shell of the nucleus accumbens (Georgescu et al, 2005;Pissios et al, 2008;Sears et al, 2010). Other differences between rat and pig projections were also noted, for example in the mammillary nuclei, as MCH axons are abundant in the medial mammillary nucleus in rat (Casatti et al, 2002), while only a modest input was noted in pig.…”

Melanin-concentrating hormone inputs to the nucleus accumbens originate from distinct hypothalamic sources and are apposed to GABAergic and cholinergic cells in the Long-Evans rat brain

“…In fact, our findings regarding MCH innervation support this functional aspect. Considering that: (1) the orexigenic behavior can be initiated by inhibiting AcbSh GABAergic projection neurons (Stratford and Kelley, 1997), (2) MCH is well characterized by its inhibitory modulation of post-synaptic signaling through GABAergic and glutamatergic receptors (Gao and van den Pol, 2001), and (3) MCH suppresses action potential firing of MSNs [attributed be GABAergic cells] into the Acb, leading to food intake (Sears et al, 2010), our findings related to the MCH-ir fibers apposed to GABA-ir neurons give anatomical support to functional data currently available regarding MCH signaling. Hedonic aspects of feeding can be influenced by dopaminergic and opioidergic systems (Kelley et al, 2005b;Wise, 2005).…”