ABSTRACT
Pain thresholds were recorded in rats by progressive increase in electrical stimulation to induce tail withdrawal, vocalisation and vocalisation after discharge. It was observed that castration resulted in significant reduction of pain threshold which however returned to normal level on substitution with testosterone therapy.
Subject(s)
Animals , Electric Stimulation , Male , Mice , Nociceptors/drug effects , Orchiectomy , Pain Measurement , Pain Threshold/physiology , Rats , Testosterone/administration & dosage , Vocalization, Animal/drug effectsABSTRACT
The ability to regulate energy level by male albino rats on administration of food with varying caloric densities, was studied. The animals fed different caloric density diets exhibited marked variations in their caloric in take in the initial stages which stabilized after 5 to 10 days and maintained on lower mean caloric intake on diet having density of 2.63 Kcal/gm, and higher mean caloric intake on diet with density of 4.88 Kcal/gm. Similar variations in body weight were also evident with failure to maintain the body weight with caloric dilution.
Subject(s)
Animal Feed/analysis , Animals , Body Weight/physiology , Diet , Energy Intake/physiology , Energy Metabolism/physiology , Feeding Behavior/physiology , Male , RatsABSTRACT
Rats were subjected to immobilization stress of varying duration and their pain thresholds were recorded. It was seen that stress of lesser duration did not affect the endogenous opioid analgesic system while stressor of longer duration stimulated this system to its maximum irrespective of further increasing the duration of the stress condition even upto two fold.
Subject(s)
Animals , Endorphins/physiology , Immobilization , Male , Pain Measurement , Pain Threshold/physiology , Rats , Stress, Psychological/physiopathology , Time Factors , Vocalization, Animal/physiologyABSTRACT
Male rats were exposed to four different stress conditions, varying in duration and intensity, during separate periods and their copulatory behaviour was studied. The number of mounts and time spent in other sexual behaviours were reduced with intensity of stressor being primarily responsible rather than prolongation of duration of a less severe stress condition.
Subject(s)
Animals , Female , Male , Rats , Sexual Behavior, Animal , Stress, Physiological , Time FactorsABSTRACT
Changes in blood pressure, heart rate and respiration were studied in 15 cats on bilateral stimulation of rostral, middle and caudal regions of caudate nucleus. Hypotensive response was obtained on stimulation of anterior caudate nucleus, which changed to pressor response when posterior caudate nucleus was stimulated. Biphasic blood pressure responses were recorded on stimulation of middle caudatal area. No detectable changes were observed on heart rate and respiration. This suggests a role for caudate nucleus as a modulator in blood pressure regulation.
Subject(s)
Animals , Blood Pressure/physiology , Brain Chemistry , Cats , Caudate Nucleus/physiology , Coloring Agents , Electric Stimulation , Electrocardiography , Female , Ferrocyanides , Heart Rate/physiology , MaleABSTRACT
Male rats were subjected to conditioning, with light source as conditioned stimulus, followed by a noxious stimulus applied to the tail as unconditioned stimulus. There was development of conditioned response after a few days, which was inhibited later on.
Subject(s)
Animals , Caudate Nucleus/anatomy & histology , Conditioning, Classical/physiology , Electric Stimulation , Male , Nociceptors/physiology , Pain/psychology , RatsABSTRACT
Rats were fed with food of different caloric densities by addition of kaolin or groundnut oil to the normal food powder. The food intake, caloric intake and body weights were noted. These observations were compared before and after bilateral destruction of mid-dorsal caudate nucleus. The food intake before caudatal lesion varied appropriately with the caloric density of food thus maintaining caloric intake and body weight. After mid-dorsal caudatal destruction this feedback mechanism of maintaining body weight was operative with low caloric density diet but not with high caloric diet.
Subject(s)
Animals , Body Weight , Caudate Nucleus/physiology , Eating , Energy Intake , Male , RatsABSTRACT
Effects of mid-dorsal caudate nucleus on sensorimotor changes were studied in rats. After electrolytic lesion of this area of brain there was impairment in sensory functions and decline in motor component was observed to be statistically significant.
Subject(s)
Animals , Brain Mapping , Caudate Nucleus/physiology , Cerebral Cortex/physiology , Dopamine/physiology , Male , Motor Activity/physiology , Orientation/physiology , Rats , Sensation/physiologyABSTRACT
Pain threshold was determined in eleven adult male rats (Haffkine strain) on electrical stimulation of midpart of tail. Three responses, namely tail withdrawal, vocalization and vocalization afterdischarge were studied. Of these eleven animals, seven in experimental group were subjected to bilateral electrolytic lesion of mid-dorsal caudate nucleus while remaining four animals were sham operated. The increase in pain threshold after caudatal destruction for all the three responses suggests the possible modulatory role of mid-dorsal caudate nucleus in the mechanism of pain.