RESUMO
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.
Assuntos
Animais , Estimulação Elétrica , Masculino , Camundongos , Nociceptores/efeitos dos fármacos , Orquiectomia , Medição da Dor , Limiar da Dor/fisiologia , Ratos , Testosterona/administração & dosagem , Vocalização Animal/efeitos dos fármacosRESUMO
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.
Assuntos
Animais , Endorfinas/fisiologia , Imobilização , Masculino , Medição da Dor , Limiar da Dor/fisiologia , Ratos , Estresse Psicológico/fisiopatologia , Fatores de Tempo , Vocalização Animal/fisiologiaRESUMO
Effects of intrastriatal injections of haloperidol (Dopamine antagonist) and D-amphetamine (Dopamine agonist) on lordosis behaviour were studied in ovariectomized female albino rats, after priming with subcutaneous injections of estrogen and progesterone. The lordosis quotient (LQ) significantly increased after haloperidol, and decreased following D-amphetamine treatment. However, the inhibitory effect of D-amphetamine was transient and could be reversed by haloperidol in the same animal when given one hour after the D-amphetamine injection. The ovarian hormones probably act centrally to suppress the DA system in the striatum thereby enhancing the tonic and dorsal immobility responses associated with lordosis.
Assuntos
Animais , Corpo Estriado/fisiologia , Dextroanfetamina/farmacologia , Dopamina/metabolismo , Estradiol/farmacologia , Feminino , Haloperidol/farmacologia , Injeções Subcutâneas , Ovariectomia , Postura , Progesterona/administração & dosagem , Ratos , Comportamento Sexual Animal/efeitos dos fármacosRESUMO
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.
Assuntos
Animais , Feminino , Masculino , Ratos , Comportamento Sexual Animal , Estresse Fisiológico , Fatores de TempoRESUMO
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.