Introduction: Natural rewards are essential for survival. However, drug-seeking behaviors can be maladaptive and endanger survival. The present study was conducted to enhance our understanding of how animals respond to food and morphine as natural and drug rewards, respectively, in a conditioned place preference (CPP) paradigm. Methods: We designed a protocol to induce food CPP and compare it ...

Experiment 1 investigates effects of different levels of start-box novelty and complexity on rats' running speed to food; Experiment 2 investigates effects of 2 degrees of goal-box novelty and complexity on the persistence of eating in the start box. Both experiments are conceptualized in a framework focusing attention on shifts from one behavior (ongoing) to another (alternative) in which late...

Food and water restriction protocols are common in animal research, yet they often elicit discussion and controversy among institutional animal care and use committee members who review them. Determining a single standard by which all restriction protocols can be evaluated or performed may not be realistic. However, information about the physiologic and behavioral impact of food and water restr...

Surplus energy is principally stored in white adipose tissue (WAT) as triacylglycerol and mobilized via lipolysis through norepinephrine (NE) released from sympathetic nervous system terminals innervating WAT. We demonstrated that central melanocortin receptor agonism provokes differential sympathetic drives across WAT pads and interscapular brown adipose tissue (IBAT). Here we tested for diffe...

Earlier studies have shown that thwarting of feeding behaviour in the laying hen is expressed through a specific vocalisation, the gakel-call. The first aim of this study was to investigate whether the effect of deprivation per se on the occurrence of gakel-calls can be distinguished from the effect of the additional frustration. Frustration is defined as the state of an animal that results fro...

Global climate models suggest an increase in evapotranspiration, changing storm tracks, and moisture delivery in many parts of the world, which are likely to cause more prolonged and severe drought, yet the weakness of climate models in modeling persistence of hydroclimatic variables and the uncertainties associated with regional climate projections mean that impact assessments based on climate...

INTRODUCTION The concentration of noradrenalin and corticosterone as the two nociception modulators change after fasting or stress situation. The aim of present study was to investigate the effect of food deprivation on formalin-induced nociceptive behaviours and plasma levels of noradrenalin and corticosterone in rats. METHODS Food was withdrawn 12, 24 and 48 h prior to performing the formal...