The amygdala, dorsal periaqueductal gray (dPAG), and medial hypothalamus have long been recognized to comprise a neural system responsible for the generation and elaboration of unconditioned fear in the brain. This neural substrate is well known to be under tonic inhibitory control exerted by γ-aminobutyric acid (GABA) mechanisms. Some evidence also suggests that these structures integrate cond...

Using a specific radioimmunoassay, we have found that immunoreactive (ir) a-neo-endorphin has a widespread and unique distribution in the rat brain and spinal cord. The highest concentration in brain is in the substantia nigra (1692.1 fmol/mg of protein). Very high concentrations of ir-a-neoedorphin (X00 fmol/mg of protein) are also found in the lateral preoptic nucleus, dentate gyrus, parabrac...

In mammals complex interactions between various brain structures and neuropeptides such as corticotropin-releasing factor (CRF) and urocortin 1 (Ucn1) underlay the control of feeding by the brain. Recently, in the amphibian Xenopus laevis, CRFand Ucn1-immunoreactivities were shown in the hypothalamic magnocellular nucleus (Mg) and evidence was obtained for their involvement in food intake. To g...

Previous studies have indicated that neurons in the dorsomedial hypothalamic nucleus (DMN) receive feeding-related signals from the gastric vagal nerves, glycemia as well as leptin. On the other hand, it is intriguing that the cerebellum participates in regulating nonsomatic visceral activities including food intake via the direct cerebellohypothalamic projections. The present study was designe...

Neuropeptide Y (NPY) acting in the hypothalamus is one of the most powerful orexigenic agents known. Of the five known Y receptors, hypothalamic Y1 and Y5 have been most strongly implicated in mediating hyperphagic effects. However, knockout of individual Y1 or Y5 receptors induces late-onset obesity--and Y5 receptor knockout also induces hyperphagia, possibly due to redundancy in functions of ...

Running wheel access and resulting voluntary exercise alter food intake and reduce body weight. The neural mechanisms underlying these effects are unclear. In this study, we first assessed the effects of 7 days of running wheel access on food intake, body weight, and hypothalamic gene expression. We demonstrate that running wheel access significantly decreases food intake and body weight and re...

Some animals and humans fed a high-energy diet (HED) are diet-resistant (DR), remaining as lean as individuals who were naïve to HED. Other individuals become obese during HED exposure and subsequently defend the obese weight (Diet-Induced Obesity- Defenders, DIO-D) even when subsequently maintained on a low-energy diet. We hypothesized that the body weight setpoint of the DIO-D phenotype resid...

The clock gene protein Per 1 (PER1) is expressed in several brain structures and oscillates associated with the suprachiasmatic nucleus (SCN). Restricted feeding schedules (RFS) induce anticipatory activity and impose daily oscillations of c-Fos and clock proteins in brain structures. Daily access to a palatable treat (chocolate) also elicits anticipatory activity and induces c-Fos expression m...

C3 neurons constitute one of three known adrenergic nuclei in the rat central nervous system (CNS). While the adrenergic C1 cell group has been extensively characterized both physiologically and anatomically, the C3 nucleus has remained relatively obscure. This study employed a lentiviral tracing technique which expresses green fluorescent protein behind a promoter selective to noradrenergic an...