Cardiovascular adjustments in limb retraction provoked by noxious stimulation in decerebrate and spinal cats: evidence for a somatotopic organization

Arterial blood pressure, heart rate and iliac blood flow were continuously recorded in 61 adult cats and their alteration induced by noxious stimulation of the interdigital spaces of the four limbs was studied in intact (anesthetized) and in decerebrate and spinal preparations. Noxious stimulation of any limb in the decerebrate animals provoked retraction 61 percent of the times and an increase of blood pressure and heart rate in approximately 80 percent of the stimulations. Stimulations of a hindlimb provoked an increase of blood flow in the same limb in about 80 percent of the stimulations, due to active vasodilation. Contralateral stimulation provoked as smaller increase of blood flow but with an increase in vascular resistance, indicating some degree of vasoconstriction. Stimulation of the forelimbs induced small increases of blood flow in the hindlimbs but the calculated vascular resistance was higher than the basal values, also indicating vasoconstriction. Neuromuscular blockade with gallamine did not affect the increase of hindlimb blood flow, suggesting a central regulation of the intricate distribution of blood to the limbs...

Theta waves and behavioral manifestations of alertness and dre4aming activity in the rat

Electro-oscillographic recordings show that when up, behavioral manifestations such as head dorsal extension and snout and eye movements (which occur in this sequence) occasionally followed by brief ear areas 3 and 17 and in the hippocampus. Heart rate increases when the animal passes from synchronized sleep to relaxed wakefulness to exploratory behavior. During desynchronized sleep theta waves, similar to those found during alertness, usually precede and are simultaneous with rostrum and eye movements and brief ear and limb twitches. Heart rate also increases during dreaming activity. A high degree of coherence (near 1.0) was found among theta bursts in different hippocampal areas in both highly attentive alertness and dreaming. It is suggested that theta waves are related to attention as part of some kinds of behavior and of the process of dream shaping and expression, both characterized by consciousness

Theta waves in the papez circuit during alertness and dreaming in the rat

An electro-oscillographic study of the hippocampus, thalamic anterior nuclei and cingulate and pericingulate cortical areas was performed in the rat during the wakefulness-sleep cycle. High voltage (usually from 100 to 200 uV) theta waves, oscvillating at regular frequencies from 6 to 10 Hz, were found to occur simultaneously in all of these components of the Papez circuit during attentive behavior and dreaming

Contractions of the gastric antrum induced by stimulation of the medial forebrain bundle in the rat

Glucoreceptors sensitive to cytoglucopenia exist in the medial forebrain bundle of the rat. The selective activation of these receptors provokes an increase in glycemia and gastric secretion. In the present work, we found that stimulation of this diencephalic area in rats also provokes potent gastric contractions. Stimulation with high voltage usually inhibited this effect

Electrical activity of the posterior thalamic nucleus and the hippocampus during wakefulness and desynchronized sleep in the rat: a spectral analysis

The electrical activity of the posterior thalamic nuclear complex was studied in rats and related to the simultaneous hippocampal electro-oscillogram. Electrocorticographic tracings and spectral analysis showed that during attentive wakefulness the electro-oscillogram peaked at 8 Hz and in desynchronized sleep it oscillated at regular frequencies between 8 and 9 Hz. In quiet wakefulness, frequency was lower (around 5 Hz) and during synchronized sleep rhytmicity disppeared. The electrophysiological patterns during wakefulness and desynchronized sleep are proposed to be linked to the retrieeval and combination of information for the generation of attention and dream content

Stationarity and normality of distribution of rat cortical brain waves

Establishing the stationarity and statistical distribution of potentials recorded from the nervous system is cricial for the application of frequency analysis. Both parameters were determined in the electrocorticograms of six adult Wistar rats during wakefulness and desynchronized sleep, during both of which desinchronization prevails. Stationarity of the signals was found to occur during at least 20 s in both states of the wakefulness-sleep cycle. A normal distribution was also found for at least 6.7 s. These findings provide strong support for the use of frequency analysis of brain waves as a reliable method to quantify neural electro-oscillograms

Rostrum movements in desynchronized sleep as a prevalent manifestation of dreaming activity in wistar rats

Considering that eye movements express visual dreams in humans and are prominent during desynchronized sleep in cats, monkeys and birds, rostrum movements were investigated in a macrosmatic species, the rat, to the hypothesis that, expressisng olfactory and tactile (involving the vibrissae) dreams, they would prevail over eye movements. Desynchronized sleep episodes lasted 148.8 ñ 12.4 s, rostrum movements lasted 80.7 ñ 6.9 s and eye movements occurred during 40.4 ñ 3.9 s, all in accordance with the original hypothesis