Physiology & behavior
-
Physiology & behavior · Feb 2003
Sleep and EEG patterns in the chronic constriction injury model of neuropathic pain.
Chronic neuropathic pain patients often report sleep disturbances such as reduced amount of sleep and excessive daytime tiredness. The aim of this study was to evaluate possible abnormalities in sleep patterns in a widely used animal model of neuropathic pain. Adult male Sprague-Dawley rats were chronically implanted with electrodes for electroencephalogram (EEG) and electromyogram (EMG) registrations to allow continuous 24-h polygraphic recording. ⋯ It is concluded that in the chronic phase, this neuropathic pain model does not produce clear sleep disturbances. Such an absence of general suffering from sleep disturbances is advantageous to the CCI model as it makes use of the model more acceptable ethically. Nonetheless, this outcome appears to be in contrast with the clinical situation in neuropathic pain and therefore could also be seen as a disadvantage for the face validity of the CCI model.
-
Glucose homeostasis is of paramount concern to the brain since glucose is its primary fuel. Thus, the brain has evolved mechanisms to sense and respond to changes in glucose levels. The efferent aspects of the central nervous system response to hypoglycemia are relatively well understood. ⋯ The various subtypes of physiologically relevant glucose-sensing neurons will then be discussed. Based on the relative glucose sensitivity of these subtypes of glucose-sensing neurons, possible roles in the regulation of glucose homeostasis are hypothesized. Finally, the question of whether these neurons are only glucose sensors or whether they play a more integrated role in the regulation of energy balance will be considered.
-
Physiology & behavior · Jun 2002
Comparative Study Clinical TrialOdors modulate pain perception: a gender-specific effect.
Odors naturally provoke emotions that are pleasant or unpleasant. Prior studies have demonstrated the effects of pleasing odors on cognition and mood perception, but no studies have reported if they influence pain perception. In the present study, we measured the effect of, and relationship between, different odors on mood and experimental pain perception. ⋯ However, the effect of odor on pain was gender specific, as only women experienced the effects of odor on pain perception. Because no relationship was found between mood and pain perception, it could suggest that different mechanisms are involved in the emotional aspects of mood and pain perception. These results and their potential clinical implications are discussed.
-
Physiology & behavior · Jun 2002
Comparative StudySex differences in the acquisition of a radial maze task in the CD-1 mouse.
The purpose of the present study was to investigate spatial processing performance in male and female CD-1 mice. A substantial literature supports the existence of significant sex differences in both human and rodent models of learning and memory. The nature of these differences is dependent upon the parameters of the task, species and strain of animal. ⋯ In addition, female mice obtained significantly fewer rewards during the final two testing sessions. The present data provide the first evidence for sex differences in radial maze learning in the CD-1 mouse, a strain known for its estrogen insensitivity. Consistent with the majority of literature that supports sex differences in spatial processing in rodents, female CD-1 mice acquired significantly fewer rewards than male CD-1 mice during an eight-arm radial maze task.
-
Physiology & behavior · Mar 2002
Effect of the 5-HT(1A) receptor agonist 8-OH-DPAT on food and water intake in chickens.
The effects of the 5-HT(1A) receptor agonist 8-OH-DPAT on food and water intake in 16-week-old male chickens were investigated. Injection of 25 or 50 microg/kg of 8-OH-DPAT 15 min before refeeding starved animals (starved-refed) produced a decrease in food intake 1 h after the start of refeeding. No effect was observed in water intake. ⋯ The results show that the effect on food intake of the agonist 8-OH-DPAT in chickens was similar to that observed in mammals. Also, the results show that the agonist-induced increase in water intake may act via a different mechanism. The results show that the 8-OH-DPAT, as in mammals, has a complex effect on food and water intake in chickens and that further works need to be carried out to understand the mechanisms involved in the food and water intake using different animal models.