37 Animals and human beings sense and react to real/potential dangerous stimuli. However, 38 the supraspinal mechanisms relating noxious sensing and nocifensive behavior are mostly 39 unknown. The collateralization and spatial organization of interrelated neurons are 40 important determinants of coordinated network function. Here we electrophysiologically 41 studied medial medullary reticulospi...

In adults, nociceptive reflexes and behavioral responses are modulated by a network of brain regions via descending projections to the spinal dorsal horn [1]. Coordinated responses to noxious inputs manifest from a balance of descending facilitation and inhibition. In contrast, young infants display exaggerated and uncoordinated limb reflexes [2]. Our understanding of nociceptive processing in ...

BACKGROUND The effect of neonatal anesthesia and pain on the developing brain is of considerable clinical importance, but few studies have evaluated noxious surgical input to the infant brain under anesthesia. Herein, the authors tested the effect of increasing isoflurane concentration on spontaneous and evoked nociceptive activity in the somatosensory cortex of rats at different postnatal ages...

Electroencephalography and ethological behavioural analysis have proved to be useful in the investigation of pain in animals in a number of applied animal welfare research environments. We have used these techniques in our laboratory to investigate the effects of age on castration pain in lambs, methods of analgesia following velvet antler removal in red deer and surgical dehorning pain in catt...

Animals have evolved several chemosensory systems for detecting potentially dangerous foods in the environment. Activation of specific sensory cells within these chemosensory systems usually elicits an aversive behavioral response, leading to avoidance of the noxious foods. Although this aversive behavioral response can be adaptive, there are many instances in which it generates "false alarms,"...

Both invertebrates and vertebrates make immediate simple reactions to noxious stimuli; a tail flip escape is typical example in crayfish. More complex sustained emotional responses, such as anxiety or fear, can be demonstrated many but until recently have not been seen crustaceans. Several recent studies found anxiety-like behavior (ALB) crayfish response electric shock social bullying, this su...

I n animals, anesthetic requirements for a supramaximal noxious stimulus are usually determined using a hemostat applied to the tail or extremity (1,2). Although a generally accepted technique, the applied force is either not stated or unknown. Furthermore, when a noxious mechanical stimulus is applied to determine neurophysiological responses (e.g., dorsal horn activity), the force is often va...

Assessment of locomotion following exposure of animals to noxious or painful stimuli can offer significant insights into underlying mechanisms of injury and the effectiveness of various treatments. We developed a novel method to track the movement of mice in two dimensions using computer vision and neural network algorithms. By using this system we demonstrated that mice exposed to chlorine (Cl...

General anesthetics (GAs) have transformed surgery through their actions to depress the central nervous system and blunt the perception of surgical insults. Counterintuitively, many of these agents activate peripheral nociceptive neurons. However, the underlying mechanisms and significance of these effects have not been explored. Here, we show that clinical concentrations of noxious i.v. and in...

This study mapped the fine-scale functional representation of tactile and noxious heat stimuli in cortical areas around the central sulcus of anesthetized squirrel monkeys by using high-resolution blood oxygen level-dependent (BOLD) fMRI at 9.4T. Noxious heat (47.5°C) stimulation of digits evoked multiple spatially distinct and focal BOLD activations. Consistent activations were observed in are...