Impaired drinking responses of rats with lesions of nucleus medianus: circadian dependence

1985 ◽  
Vol 248 (2) ◽  
pp. R224-R230 ◽  
Author(s):  
T. W. Gardiner ◽  
E. M. Stricker
Keyword(s):  
Systemic Treatment ◽  
Drinking Behavior ◽  
Organ Support ◽  
Sensory Receptors ◽  
Stimulant Drug ◽  
Electrolytic Lesions ◽  
Ventral Nucleus ◽  
Glycol Solution ◽  
The Brain ◽  
Behavior Of Rats

The drinking behavior of rats with electrolytic lesions of ventral nucleus medianus (vNM) was examined during acute hyperosmolality and hypovolemia. The brain-damaged animals were impaired in their drinking responses to systemic treatment with hypertonic saline or polyethylene glycol solution when they were tested during the day. However, apparently normal drinking responses to both dipsogenic challenges were observed when the same animals were pretreated with the stimulant drug, caffeine, or when they were tested at night. These results suggest that lesions of vNM may produce complex alterations in the control of drinking behavior rather than the destruction of sensory receptors. The lesions appear to disrupt both circadian influences on drinking and activational components of drinking that normally serve to facilitate the behavioral response. The present results, together with similar findings for rats given lesions of the subfornical organ, support recent proposals that periventricular tissue bordering the rostral wall of the third cerebral ventricle plays an important role in the central control of drinking.

Hyperdipsia in rats after electrolytic lesions of nucleus medianus

1985 ◽  
Vol 248 (2) ◽  
pp. R214-R223 ◽  
Author(s):  
T. W. Gardiner ◽  
E. M. Stricker
Keyword(s):  
Drinking Behavior ◽  
Plasma Renin ◽  
Neural Substrates ◽  
Physiological Changes ◽  
Electrolytic Lesions ◽  
Daily Water ◽  
Ad Libitum ◽  
Elevated Water ◽  
Fluid Losses ◽  
The Brain

Ablation of the ventral portion of nucleus medianus (vNM) in rats produced a temporary adipsia or hypodipsia that was accompanied by pronounced urinary fluid losses. When ad libitum drinking resumed, about half of the brain-damaged animals became hyperdipsic, exhibiting chronic two- to threefold elevations in their daily water intakes during the nocturnal hours of the day-night cycle. Rats that remained normodipsic after vNM ablation usually exhibited hyperdipsia if they were food-deprived overnight. The basis for the hyperdipsia produced by vNM ablation was not clear. The elevated water intakes appeared not to result from chronic urinary fluid losses, because hyperdipsic rats were able to concentrate their urine during the day, when they drank little. Moreover, the animals did not seem to be volume depleted; their plasma renin activities were not elevated, and they drank normally in association with meals. These and other findings suggest that vNM lesions damage neural substrates that control drinking behavior, and the hyperdipsia results from this rather than from physiological changes produced by the lesion.

Abstract P059: A A Role of Aminopeptidase A in the Brain on Cardiovascular Regulation of Conscious Rat

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Takuto Nakamura ◽  
Masanobu Yamazato ◽  
Akio Ishida ◽  
Yusuke Ohya
Keyword(s):  
Blood Pressure ◽  
Protein Expression ◽  
Drinking Behavior ◽  
Cardiovascular Regulation ◽  
Ang Ii ◽  
Hypertensive Rats ◽  
Aminopeptidase A ◽  
The Brain

Objective: Aminopeptidase A (APA) have important role in conversion of Ang II to Ang III. Intravenous APA administration lowers blood pressure in hypertensive rats. In contrast, APA inhibition in the brain lowers blood pressure in hypertensive rats. Therefore APA might have different role on cardiovascular regulation. However, a role of APA and Ang III on cardiovascular regulation especially in the brain has not been fully understood. Our purpose of present study was to investigate a role of APA and Ang III in the brain on cardiovascular regulation in conscious state. Method: 12-13 weeks old Wistar Kyoto rat (WKY) and 12-16 weeks old spontaneously hypertensive rat (SHR) were used. i) APA distribution in the brain was evaluated by immunohistochemistry. Protein expression of APA was evaluated by Western blotting. Enzymatic activity of APA was evaluated using L-glutamic acid γ-(4-nitroanilide) as a substrate. ii) WKY received icv administration of Ang II 25ng/2μL and Ang III 25ng/2μL. We recorded change in mean arterial pressure (MAP) in conscious and unrestraied state and measured induced drinking time. iii) SHR received icv administeration of recombinant APA 400ng/4μL. We recorded change in MAP in conscious and unrestraied state and measured induced drinking time. Result: i) APA was diffusely immunostained in the cells of brain stem including cardiovascular regulatory area such as rostral ventrolateral medulla. Protein expression and APA activity in the brain were similar between WKY (n=3) and SHR (n=3).ii) Icv administration of Ang II increased MAP by 33.8±3.8 mmHg and induced drinking behavior for 405±90 seconds (n=4). Icv administration of Ang III also increased MAP by 24.7±2.4 mmHg and induced drinking behavior for 258±62 seconds (n=3). These vasopressor activity and induced drinking behavior was completely blocked by pretretment of angiotensin receptor type 1 blocker.iii) Icv administration of APA increased MAP by 10.0±1.7 mmHg (n=3). Conclusion: These results suggested that Ang III in the brain increase blood pressure by Angiotensin type 1 receptor dependent mechanism and APA in the brain may involved in blood pressure regulation as a vasopressor enzyme.

Alterations in feeding and drinking behavior of rats with lesions in globi pallidi

1961 ◽  
Vol 201 (3) ◽  
pp. 420-428 ◽  
Author(s):  
P. J. Morgane
Keyword(s):  
Drinking Behavior ◽  
Medial Part ◽  
Feeding System ◽  
Lateral Hypothalamic ◽  
Hypothalamic Syndrome ◽  
Far Lateral ◽  
Feeding Center ◽  
Bilateral Lesions ◽  
Globi Pallidi ◽  
Behavior Of Rats

Stereotaxic lesions were placed in several parasagittal planes of the lateral hypothalamus of rats at the level of the ventromedial nuclei. Both far- and mid-laterally lesioned animals developed adipsia and aphagia, with the far-lateral syndrome being more drastic in nature. The qualitatively different nature of the "failures" seen between the two groups correlated well with the additional damage to the pallidofugal fiber systems in the far-lateral lesioned group. Bilateral lesions directed to the origins of the pallidofugal fibers reproduced faithfully the far-lateral hypothalamic syndrome, histological studies in these animals revealing degeneration along the pallidofugal trajectories. It appears that the feeding and/or drinking "centers" are only convergence sites for critical fiber systems which are disjoined by far-lateral hypothalamic lesions. Thus, the medial part of the "feeding center" seems to be primarily a "motivational" system, whereas the lateral "feeding" system is more basic and depends essentially on pallidofugal circuitry. When this latter is disjoined, the failure is more than "motivational," since it is not compensated for by merely delivering food and water to the gastrointestinal tract.

scholarly journals Angiotensins in the central mechanisms of drinking instrumental activity of rats with different manifestations of risk behavior

2018 ◽  
Vol 26 (2) ◽  
pp. 222-228
Author(s):  
Roman Ya. Vlasenko ◽  
Alexander V. Kotov
Keyword(s):  
Risk Behavior ◽  
Lateral Ventricle ◽  
Soft Tissues ◽  
Drinking Behavior ◽  
Male Rats ◽  
Internal Diameter ◽  
Instrumental Activity ◽  
The Usa ◽  
The Brain ◽  
Purposive Behavior

Aim. To carry out a comparative analysis of characteristics of drinking instrumental activity in rats with different manifestation of risk behavior before and after intracerebral introduction of equally productive dipsogenic doses of angiotensins. Materials and Мethods. The work was conducted on 19 Wistar male rats of 250300 g mass. All manipulations with animals were performed in accordance with the international ethic recommendations on biomedical research with use of animals. All rats were preliminarily scalped under ether anesthesia with removal of soft tissues and periosteum. The cannulae were introduced into rat’s brain through the trephine opening in the lateral ventricle. The length of each cannula was 8 mm, the internal diameter – 0.8 mm. All cannulae had a special restrictor at the distance of about 3.5 mm from the implantable end. Each animal was implanted one cannula into the lateral ventricle of the brain on the right or left side according to the coordinates of stereotaxic atlas for rats (L.D. Pellegrino at al., 1979) (AP = +1.0; L= 2; H= 2.5). Microinjections of substances were made into the brain of nonnarcotized animals using a microsyringe of 5 μL volume («Hamilton», the USA). For intraventricular microinjections, angiotensinII, angiotensinIII and [des – Asp1]angiotensinI («Sigma», the USA) were used. Results. In the article the mechanisms of realization of drinking instrumental activity in rats with different manifestations of risk behavior are described. In view of P.K. Anokhin’s general theory of functional systems, the effects of application of «equally productive» doses of angiotensins on initiation of specific patterns of drinking behavior in rats are discussed. Risk is considered as an independent component of systemic organization of purposive behavior of an individual. It is shown that the «integral pattern of individual behavior» of rats is selectively modulated by angiotensinII and angiotensinIII. This selectivity has a narrow focus and individual manifestations, depending on the background activity of the animals. Conclusion. Depending on the initial level of the intensity of instrumental activity of the animals (with different manifestations of risk behavior), angiotensin II and angiotensin III are involved into initiation of fullscale «integral pattern of individual drinking behavior» or participate in the directed modulation of complex purposive behavior manifested by enhancement of dipsogenic effect. At the same time, [des – Asp1]angiotensinI does not participate in the mechanisms of reproduction of the acquired drinking instrumental habits but induces only mechanisms of initiation of congenital individual forms of drinking behavior.

Central nervous control of voluntary food intake

1989 ◽  
Vol 13 ◽  
pp. 7-26 ◽  
Author(s):  
J. M. Forbes ◽  
J. E. Blundell
Keyword(s):  
Nervous System ◽  
Food Intake ◽  
Peptide Yy ◽  
Blood Stream ◽  
Vital Role ◽  
Nervous Control ◽  
Electrolytic Lesions ◽  
The Central Nervous System ◽  
The Brain ◽  
Voluntary Food Intake

AbstractThe central nervous system is the integrator of most of the actions of the animal and as such plays a vital rôle in the control of voluntary food intake. Much of the work to understand how intake is controlled has been carried out with rats but that which has been done with pigs is included. The first experiments used electrolytic lesions in the designation of the ‘hunger centre’ and the ‘satiety centre’. Recent work has identified the paraventricular nucleus as a sensing site for experimental manipulations. Chemical stimulation of the brain has also been carried out to try to gain understanding of the rôle of neurotransmitters. Noradrenaline (NA) stimulates intake when given into many sites. Serotonin (5-HT) inhibits intake and has been claimed to play a rôle in the selection of macronutrients but 5-HT must now be interpreted in the light of the existence of several different subtypes of 5-HT receptors. Dopamine appears to moderate the hedonic response of eating. Numerous peptides are active in the brain where their rôle as neuromodulators may be quite different from their function in the periphery and at least three types of opioid receptors are implicated with kappa antagonists producing the most potent facilitatory effects. Neuropeptide Y and peptide YY produce massive orexigenic effects which readily overcome peripheral satiety factors. The brain cannot control intake in isolation. It receives inputs in the blood stream, such as glucose, as well as via the nervous system, both from the special senses and from visceral organs such as stomach, intestines and liver. Taste and olfaction are important in diet selection and a specific appetite for protein has been demonstrated in the pig.

scholarly journals Efficacy of Cidofovir in a Murine Model of Disseminated Progressive Vaccinia

2004 ◽  
Vol 48 (6) ◽  
pp. 2267-2273 ◽  
Author(s):  
Johan Neyts ◽  
Pieter Leyssen ◽  
Erik Verbeken ◽  
Erik De Clercq
Keyword(s):  
Animal Model ◽  
Protective Effect ◽  
Murine Model ◽  
Topical Treatment ◽  
Systemic Treatment ◽  
The Body ◽  
Athymic Mice ◽  
Cutaneous Lesions ◽  
Visceral Organs ◽  
The Brain

ABSTRACT An animal model that mimics progressive disseminated vaccinia was elaborated. To this end nude (athymic) mice were inoculated intracutaneously with vaccinia virus in the lumbosacral area. Viral replication (DNA) in the skin was detected as early as day 2 postinfection (p.i.). Mice developed typical vaccinia lesions at the site of inoculation by day 4 to 6 p.i. By about 2 weeks p.i., the infection had spread all over the body, a situation reminiscent of disseminated vaccinia in humans. The infection resulted in viremia and spread of the virus to visceral organs, as well as to the brain. Topical treatment with cidofovir, initiated at the day of infection or at day 1 p.i., completely protected against virus-induced cutaneous lesions and against associated mortality. When treatment was initiated at a later time (day 2 to 5 p.i.), a partial but marked protective effect was noted, which can be explained by the fact that by that time, the virus had spread from the skin to the visceral organs. Next, infected animals were left untreated until the time (∼2 weeks p.i.) at which disseminated vaccinia had developed. When systemic treatment with cidofovir was initiated at that time, it caused lesions to heal and regress. In most of these animals, lesions had completely (or almost completely) disappeared by day 10 to 15 after the start of therapy. The observation that cidofovir is able to cause healing of disseminated vaccinia lesions in animals should have implications for the therapy of complications of vaccination against smallpox.

Precocious ovarian stimulation following hypothalamic and amygdaloid lesions in rats

1960 ◽  
Vol 198 (2) ◽  
pp. 381-385 ◽  
Author(s):  
Mildred Elwers ◽  
Vaughn Critchlow
Keyword(s):  
Ovarian Stimulation ◽  
Histological Study ◽  
Amygdaloid Complex ◽  
Female Rats ◽  
Gonadotropin Secretion ◽  
Functional Development ◽  
Electrolytic Lesions ◽  
Basal Septum ◽  
The Brain ◽  
Hypothalamic Mechanism

The effects of neural lesions on the functional development of the reproductive system were studied in prepubertal female rats. Small electrolytic lesions were placed bilaterally in 66 female rats at 18–20 days of age; 42 littermates served as controls, and 7 rats were blank-operated. All animals were weighed two to three times a week and examined daily for vaginal opening. At 33 days of age the uteri, ovaries and adrenals were weighed and prepared for histological study. All brains were examined histologically for lesion localization. Lesions in the anterior hypothalamus or in the medial portion of the amygdaloid complex were associated with precocious ovarian stimulation. With the exception of one lesion in the basal septum and one in caudate-putamen, bilaterally symmetrical lesions in other parts of the brain and asymmetrical lesions have been ineffective. These results are compatible with an anterior hypothalamic mechanism involved in the inhibition of gonadotropin secretion and suggest the inclusion of the medial portion of the amygdaloid complex in this mechanism.

Arterial baroreceptors mediate the inhibitory effect of acute increases in arterial blood pressure on thirst

2002 ◽  
Vol 282 (6) ◽  
pp. R1718-R1729 ◽  
Author(s):  
Sean D. Stocker ◽  
Edward M. Stricker ◽  
Alan F. Sved
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Drinking Behavior ◽  
Plasma Osmolality ◽  
Inhibitory Effect ◽  
Ang Ii ◽  
Arterial Blood ◽  
Acute Increase ◽  
Behavior Of Rats ◽  
Arterial Baroreceptor

The present study sought to determine whether arterial baroreceptor afferents mediate the inhibitory effect of an acute increase in arterial blood pressure (AP) on thirst stimulated by systemically administered ANG II or by hyperosmolality. Approximately 2 wk after sinoaortic denervation, one of four doses of ANG II (10, 40, 100, or 250 ng · kg−1 · min−1) was infused intravenously in control and complete sinoaortic-denervated (SAD) rats. Complete SAD rats ingested more water than control rats when infused with 40, 100, or 250 ng · kg−1 · min−1 ANG II. Furthermore, complete SAD rats displayed significantly shorter latencies to drink compared with control rats. In a separate group of rats, drinking behavior was stimulated by increases in plasma osmolality, and mean AP was raised by an infusion of phenylephrine (PE). The infusion of PE significantly reduced water intake and lengthened the latencies to drink in control rats but not in complete SAD rats. In all experiments, drinking behavior of rats that were subjected to sinoaortic denervation surgery but had residual baroreceptor reflex function (partial SAD rats) was similar to that of control rats. Thus it appears that arterial baroreceptor afferents mediate the inhibitory effect of an acute increase in AP on thirst stimulated by ANG II or hyperosmolality.

Sign in / Sign up

Export Citation Format

Share Document