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F Mora

Publications and source records attributed to F Mora.

At least 145 records · Page 8Linked to original sources
PubMed1983

Involvement of alpha- and beta-adrenoreceptors in the central action of norepinephrine on temperature, metabolism, heart and respiratory rates of the conscious primate.

The effect of the central blockade of alpha- and beta-adrenoreceptors on the action of norepinephrine (NE) infused by the intracerebroventricular (ICV) route was examined in the unanesthetized primate. After cannulae for ICV infusion were implanted sterotaxically, each monkey (Macaca fasicularis) was placed in a restraint chair fitted with a transparent dome for measurement of O2 uptake. During an experiment, the following responses were monitored simultaneously on a polygraph: skin and colonic temperatures, heart and respiratory rates, and metabolic rates as reflected by O2 uptake. Following an ICV infusion of 150 micrograms NE, colonic temperature, heart and metabolic rates declined while skin temperature increased and respiratory rate remained unchanged. Pretreatment with ICV phentolamine (100 micrograms), an alpha-adrenoreceptor antagonist, attenuated the changes in temperature, heart and metabolic rates and reduced respiratory rate. Similar ICV infusion of 100 micrograms propranolol, a beta-adrenoreceptor antagonist, tended also to attenuate the responses induced by NE, but overall was much less efficacious than phentolamine. Our results indicate that although catecholaminergic neurons mediate these vital physiological processes principally by central alpha-adrenoreceptors, a substantial beta-adrenoreceptor component also participates in the mechanism responsible for specific functional changes.

Animals↗
PubMed1983

Putative amino acid neurotransmitters and the nucleus dorsomedialis thalamus-prefrontal cortex pathway in the rat.

Endogenous levels of putative amino acid neurotransmitters (glycine, glutamic acid, aspartic acid, and GABA) in medial and sulcal prefrontal cortex of the rat were analyzed using gas liquid chromatography. No changes were found in the levels of these amino acids in medial and sulcal prefrontal cortex after lesion of the nucleus dorsomedialis of the thalamus suggesting, therefore, that the NDMT-prefrontal cortex pathway is not mediated by these amino acids.

Amino Acids↗
PubMed1983

Monoamines and self-stimulation of the medial prefrontal cortex in the rat.

The participation of noradrenaline (NE) and serotonine (5-HT) in self-stimulation (SS) of the medial prefrontal cortex (MPC) in the rat has been studied. Three groups of rats with bilateral electrodes implanted into the MPC were used in these experiments. In one of the groups, electrodes were also implanted into the locus coeruleus. In the first group, the rats received systemic injections of the following drugs: clonidine (alpha-agonist), phenoxybenzamine (alpha-antagonist), isoproterenol (beta-agonist) and propranolol (beta-antagonist). In the second group, p-chlorophenylalanine (a 5-HT synthesis inhibitor) was administered intragastrically and SS measured during the following 16 days. In these two groups of rats and previous to every SS session, spontaneous motor activity (SM) was measured as control for non specific effects of the drugs. In a third group of rats, lesions of the locus coeruleus were performed unilaterally and SS measured in both prefrontal cortex during the following 16 days post-lesion. SS contralateral to the lesioned side served as control for non-specific effects of the lesions. After all these treatments, SS of the MPC was not specifically affected. Our results suggest the non participation of NE and 5-HT terminals in the neural substrates underlying SS of the MPC.

Adrenergic alpha-Antagonists↗
PubMed1982

Temperature regulation and dopaminergic systems in the brain: does the substantia nigra play a role?

Male Sprague-Dawley rats (250-300 g) were stereotaxically implanted above the substantia nigra (SN) and preoptic/anterior hypothalamus (PO/AH) with 23 gauge stainless-steel guide tubes. Microinjections of apomorphine (APO), pimozide, or 0.9% saline were made bilaterally in 0.5 or 1.0 microliter vols. using a Harvard infusion pump. Oxygen consumption, and colonic (Tc), tail-skin, and ambient temperatures were monitored each minute. Microinjections of APO into the SN produced a dose dependent hypothermia that was antagonized by the central (1.0 microgram) or systemic (0.5mg/kg i.p.) injection of pimozide. This hypothermia was associated with increased heat loss and decreased heat production and occurred at ambient temperatures of 15, 23 and 25 degree C indicating that APO did not produce a poikilothermic state. Injecting 20 microgram APO into the PO/AH or SN produced similar hypothermic responses; Tc fell 0.87 /+- 0.10 degree C and 1.02 /+- 0.08 degree C, respectively. Pimozide injected into the SN failed to alter thermoregulation during exercise or exogenous heating. Moreover, systemic injections of APO before and after electrolytic lesioning of the SN produced similar hypothermic responses. However, when the SN was lesioned, (a) resting Tc was significantly reduced, and (b) during exposure to a 35 degree C environment for 55 min, Tc rose to 39.5 /+- 0.68 degree C before the lesion compared with a rise to only 38.5 /+- 0.13 degree C after the lesion. We conclude that the pharmacological data implicate a thermoregulatory role for dopamine receptors in the rat, but the functional significance of this central location in temperature regulation remains to be elucidated.

Animals↗
PubMed1982

Gastroplasty with partial or total plication for gastroesophageal reflux: manometric and pH-metric postoperative studies.

From January, 1975, to December, 1980, 83 patients with sliding hiatal hernia, gastroesophageal reflux, or both were treated using a modified Collis gastroplasty associated with either partial or total gastric application. When partial plication was used, the five-year clinical results were considered satisfactory in 27 out of 35 patients (77%). When total plication was used, the results were satisfactory in 41 out of 46 patients (89%) after follow-up ranging from 12 to 60 months (average, 36 months), but no symptoms of gastroesophageal reflux reappeared in any patient. In patients undergoing partial plication, the mean preoperative high-pressure zone of 11.20 +/- 8.19 mm Hg increased after operation to 17.31 +/- 10.50 mm Hg, but in the second postoperative studies the value decreased to 13.69 +/- 7.24 mm Hg. When 360 degrees plication was used, the preoperative value of the high-pressure zone--9.36 +/- 4.80 mm Hg--increased after operation to 17.70 +/- 7.53 mm Hg but did not decrease significantly in the second postoperative studies: 16.46 +/- 7.99 mm Hg. When partial plication was used, the positivity of the abdominal compression test was 9 and 28% in the early and late postoperative studies, respectively. Using total plication, the percentage of positivity in the early and late postoperative periods was 0 and 2%, respectively. Concerning the acid reflux test, when partial plication was used, the test was positive in 3 out of 27 patients (11%) in the early postoperative studies and in 7 out of 30 (23%) one year later. For the total plication procedure, the percentage of positive tests was null in the first control and 3% in the second postoperative studies.

Deglutition Disorders↗
PubMed1982

Visceral larva migrans-like syndrome caused by Angiostrongylus costaricensis.

In two cases of ectopic localization of Angiostrongylus costaricensis adult worms and eggs were seen in the liver, causing a granulomatous inflammatory reaction with dense eosinophilic infiltration and necrosis. In the first case, although antibodies for A. costaricensis had been demonstrated, a clinical diagnosis of visceral larva migrans was recorded; however, further examination of a liver biopsy revealed eggs of A. costaricensis. In the second case, severity of the intestinal pathology masked the presence of lesions and an adult A. costaricensis that were discovered in a retrospective study of the liver 13 years later. A close similarity between the visceral larva migrans syndrome and ectopic localization (liver) of A. costaricensis is established.

Angiostrongylus↗
PubMed1981

Intracerebral self-administration of amphetamine by rhesus monkeys.

Four rhesus monkeys received intracranial implantation of cannulae aimed at the orbitofrontal cortex. Electrical intracranial self-stimulation was obtained readily from insulated electrodes placed temporarily into the orbitofrontal cortex via the outer guide tubes. Subsequently, each subject acquired a panel press operant response to deliver 0.05 microliter of D-amphetamine (10-6 M) into the orbitofrontal cortex via an inner cannula. The rate of panel pressing increased over several daily test sessions and extinguished after substitution of the vehicle solution. One animal responded readily on a fixed ratio-10 schedule. Control injections into the nucleus accumbens and lateral ventricles failed to maintain self-administration behavior.

Animals↗
PubMed1981

Motor activity after colon replacement of esophagus. Manometric evaluation.

Motor activity of the colon transplant for esophageal reconstruction is a point of controversy. In this paper we present manometric studies carried out in 15 patients subjected to isoperistaltic colon interposition. Manometric studies were carried out with two polyvinyl water-filled catheters inserted through pressure transducers. Basal colonic activity and motor activity following several stimuli and "dry swallows" were registered. The type of waves after stimuli were classified as (1) synchronous, (2) sequential or progressive, and (3) segmental. Details of the basal colonic waves and colon contractions after stimuli are given: i.e., rate, duration, amplitude, interval from the stimulus, and percentage of motor activity. The data reported here indicate the good motor response of the isoperistaltic colon to intraluminal injection of water or 0. 1 N hydrochloric acid and to chachet swallowing. Only two free-symptoms patients did not have motor activity. One of them was submitted to manometric studies too soon after the operation. We conclude that the presence of sequential waves in the interposed segment likely can help to propel the contents of the colon into the stomach and to clear gastric juice if reflux from the stomach should occur.

Adolescent↗
PubMed1980

Evidence for an involvement of acetylcholine in self-stimulation of the prefrontal cortex in the rat.

The effects of injections of antagonists of muscarinic and nicotinic receptors on self-stimulation of the prefrontal cortex in the rat were studied. The results of this investigation suggest that acetylcholine is involved in self-stimulation of the prefrontal cortex through activation of muscarinic receptors, and also suggest a possible interaction between acetylcholine and dopamine in mediating self-stimulation of this area of the brain.

Acetylcholine↗
PubMed1980

Neurophysiological analysis of brain-stimulation reward in the monkey.

Neuronal activity related to brain-stimulation reward and to feeding was analyzed in rhesus monkeys and squirrel monkeys as follows. First, self-stimulation of the lateral hypothalamus, orbitofrontal cortex, amygdala and nucleus accumbens was found. Second, a population of single neurones in the lateral hypothalamus was found to be trans-synaptically activated from one or several self-stimulation sites. It was also found to populations of neurones in the orbitofrontal cortex and amygdala were activated from at least some of the self-stimulation sites. Thus, in the monkey, there is evidence for an interconnected set of self-stimulation sites, stimulation in any one of which may activate neurones in the other regions. These sites include the lateral hypothalamus, amygdala, and orbitofrontal cortex. Third, in one sample of 764 neurones in the lateral hypothalamus and substantia innominata which were activated from brain-stimulation reward sites, 13.6% were also activated during feeding, by the sight and/or taste of food. The responses of the neurones with activity associated with taste occurred only while some substances (e.g. sweet substances such as glucose) were in the mouth, depended on the concentration of the substances being tasted, and were independent of mouth movements made by the monkeys. Fourth, the responses of these neurones occurred to food when the monkeys were hungry, but not when they were satiated. Fifth, self-stimulation occurred in the region of these neurones in the lateral hypothalamus and substantia innominata, and was attenuated by satiety. These results suggest that self-stimulation of some brain sites occurs because of activation of neurones in the lateral hypothalamus and substantia innominata activated by the sight and/or taste of food in the hungry animal, and that these neurones are involved in responses to food reward.

Amygdala↗
PubMed1980

Effects of apomorphine and pimozide on temperature regulation during exercise in the rat.

The purpose of this study was to determine the effects of a specific dopamine receptor agonist (apomorphine) and antagonist (pimozide) on thermoregulation when the heat loss pathway was activated by the stress of exercise. Apomorphine or its control vehicle (0.9% wt/vol saline) was injected systemically (0.5, 1.0, 1.5 mg/kg ip) or within the preoptic-anterior hypothalamus (5, 10, 20 micrograms) immediately before the start of treadmill exercise at 21.5 m/min. Colonic, tailskin, and ambient temperatures were recorded each minute. Oxygen consumption was calculated from on-line measurements of percent O2 and CO2. Pimozide injected systemically (0.5 mg/kg ip) had no effect on resting colonic temperature, but caused a significant (P less than 0.05) hyperthermia during treadmill exercise compared to saline controls. Central and systemic injections of apomorphine caused a dose-dependent hypothermia that was blocked by pretreatment with pimozide. Oxygen uptake values during exercise following the central injection of apomorphine were virtually identical to those following the injection of saline, but colonic temperature was significantly (P less than 0.05) lower than saline controls, indicating that the hypothermia observed was not due to a reduction in metabolic rate. These data indicate that dopamine receptors in the preoptic-anterior hypothalamus of the rat participate in the mediation of heat dissipation when the animal is challenged with a heat stress.

Animals↗
PubMed1979

Intracranial self-stimulation in orbitofrontal cortex and caudate nucleus of rhesus monkey: effects of apomorphine, pimozide, and spiroperidol.

Rhesus monkeys were prepared with stimulating electrodes implanted into the orbitofrontal cortex and head of the caudate nucleus under stereotaxic control. These regions of the brain contain high levels of dopamine, and intracranial self-stimulation was readily elicited from these loci in all animals tested using licking behavior as the operant response. Self-stimulation at both sites was significantly attenuated following peripheral injections of the dopamine receptor blocker spiroperidol (0.02 mg/kg). Similarly, pimozide (0.15 and 0.20 mg/kg) significantly reduced self-stimulation in the orbitofrontal cortex, but the suppression observed at caudate placements did not reach statistical significance. Licking for a reward of blackcurrant juice was unaffected by either drug. Apomorphine (0.2, 0.4 mg/kg) had a differential effect on self-stimulation. This drug significantly attenuated self-stimulation in the orbitofrontal cortex, while the same treatment tended to facilitate self-stimulation in the caudate. Apomorphine did not significantly affect responding for the fruit juice reward. The parallels between the effects of dopamine agonists and antagonists on self-stimulation in the monkey and rat suggest that dopamine influences self-stimulation of some sites in both the primate and the rat.

Animals↗
PubMed1979

Effects of satiety on self-stimulation of the orbitofrontal cortex in the rhesus monkey.

Self-stimulation of the orbitofrontal cortex of the rhesus monkey was found to be attenuated after the monkeys were fed to satiety. Self-stimulation at some other sites (e.g. the nucleus accumbens septi, the region of the substantia nigra, and the caudate nucleus) was relatively unaffected in the same test sessions by the satiety. In recordings from single neurons in the monkey orbitofrontal cortex, neurons of the type found in the lateral hypothalamus with sustained responses associated with the sight of preferred foods were not found. However, some orbitofrontal neurons did respond to the removal of food or other desired objects. These experiments show that self-stimulation of the monkey orbitofrontal cortex in modulated by hunger, and show that some orbitofrontal neurons have complex responses which could be related to the control of feeding.

Animals↗