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.

Impairment in fluid ingestion in rats with lesions of the zona incerta

1977 ◽  
Vol 233 (1) ◽  
pp. R53-R58 ◽  
Author(s):  
M. D. Evered ◽  
G. J. Mogenson
Keyword(s):  
Water Intake ◽  
Water Deprivation ◽  
Zona Incerta ◽  
Subsequent Reduction ◽  
Fluid Ingestion ◽  
Daily Water Intake ◽  
Daily Water ◽  
Ad Libitum ◽  
The Brain ◽  
Excessive Water

Rats with lesions of the zona incerta (ZI) dorsal to the lateral hypothalamus drink as much water as controls following intracellular or extracellular dehydration but restrict their daily water intake to minimal requirements for fluid balance, suggesting a specific impairment in secondary drinking. Following water deprivation, however, rats with ZI lesions responded to changes in palatability of the water as if they were experiencing slightly greater difficulty or aversiveness in drinking than controls. The cause appears to be an impairment in the ability to lick fluids from a spout. When water was available ad libitum or when water or liquid diet were provided after water or food deprivation, rats with ZI damage were unable to obtain as much fluid per lick as controls. It is concluded that lesions in this region of the brain impair the motor act of drinking and that the subsequent reduction in the efficiency of drinking is the cause of the attenuation of excessive water intake.

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.

Lessons From the Neural Bases of Speech and Voice

2011 ◽  
Vol 21 (1) ◽  
pp. 5-14
Author(s):  
Christy L. Ludlow
Keyword(s):  
Brain Networks ◽  
Neural Substrates ◽  
Voice Behavior ◽  
Therapeutic Approaches ◽  
Neural Bases ◽  
Sound Foundation ◽  
The Brain ◽  
Normal Speech

The premise of this article is that increased understanding of the brain bases for normal speech and voice behavior will provide a sound foundation for developing therapeutic approaches to establish or re-establish these functions. The neural substrates involved in speech/voice behaviors, the types of muscle patterning for speech and voice, the brain networks involved and their regulation, and how they can be externally modulated for improving function will be addressed.

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.

scholarly journals Brain network dynamics correlate with personality traits

2019 ◽  
Author(s):  
Aya Kabbara ◽  
Veronique Paban ◽  
Arnaud Weill ◽  
Julien Modolo ◽  
Mahmoud Hassan
Keyword(s):  
Functional Connectivity ◽  
Personality Traits ◽  
Resting State ◽  
Brain Networks ◽  
Neural Substrates ◽  
Brain Network ◽  
Functional Brain ◽  
Human Connectome Project ◽  
Functional Brain Networks ◽  
The Brain

AbstractIntroductionIdentifying the neural substrates underlying the personality traits is a topic of great interest. On the other hand, it is now established that the brain is a dynamic networked system which can be studied using functional connectivity techniques. However, much of the current understanding of personality-related differences in functional connectivity has been obtained through the stationary analysis, which does not capture the complex dynamical properties of brain networks.ObjectiveIn this study, we aimed to evaluate the feasibility of using dynamic network measures to predict personality traits.MethodUsing the EEG/MEG source connectivity method combined with a sliding window approach, dynamic functional brain networks were reconstructed from two datasets: 1) Resting state EEG data acquired from 56 subjects. 2) Resting state MEG data provided from the Human Connectome Project. Then, several dynamic functional connectivity metrics were evaluated.ResultsSimilar observations were obtained by the two modalities (EEG and MEG) according to the neuroticism, which showed a negative correlation with the dynamic variability of resting state brain networks. In particular, a significant relationship between this personality trait and the dynamic variability of the temporal lobe regions was observed. Results also revealed that extraversion and openness are positively correlated with the dynamics of the brain networks.ConclusionThese findings highlight the importance of tracking the dynamics of functional brain networks to improve our understanding about the neural substrates of personality.

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.

Environments, Past and Present

2020 ◽  
Author(s):  
Angela Duckworth ◽  
Keyword(s):  
Allostatic Load ◽  
Acute Stress ◽  
The Body ◽  
Physiological Changes ◽  
Long Term Effects ◽  
Flight Response ◽  
Fight Or Flight Response ◽  
The Brain ◽  
Fight Or Flight

For more than a century, scientists have known that acute stress activates the fight-or-flight response. When your life is on the line, your body reacts instantly: your heart races, your breath quickens, and a cascade of hormones sets off physiological changes that collectively improve your odds of survival. More recently, scientists have come to understand that the fight-or-flight response takes a toll on the brain and the body—particularly when stress is chronic rather than acute. Systems designed to handle transient threats also react to stress that occurs again and again, for weeks, months, or years. It turns out that poverty, abuse, and other forms of adversity repeatedly activate the fight-or-flight response, leading to long-term effects on the immune system and brain, which in turn increase the risk for an array of illnesses, including asthma, diabetes, arthritis, depression, and cardiovascular disease. Pioneering neuroscientist Bruce McEwen called this burden of chronic stress “allostatic load.”

The kidneys stimulate vasopressin release during hemorrhage in rats with chronic NTS lesions

1997 ◽  
Vol 272 (5) ◽  
pp. R1540-R1551 ◽  
Author(s):  
A. M. Schreihofer ◽  
G. E. Hoffman ◽  
A. F. Sved
Keyword(s):  
Renal Denervation ◽  
Critical Role ◽  
Plasma Renin ◽  
Afferent Input ◽  
Renal Nerves ◽  
Solitary Tract ◽  
Vasopressin Release ◽  
Afferent Signal ◽  
The Brain ◽  
Intact Rats

Elimination of baroreceptor afferent input to the brain produced by chronic lesion of nucleus of the solitary tract (NTS) does not alter vasopressin (VP) release during hypotensive hemorrhage in conscious rats. To investigate whether the kidneys play a critical role in stimulating VP release during hemorrhage in chronic NTS-lesioned rats, we examined the effects of removing potential signals arising from the kidneys. In NTS-lesioned rats, nephrectomy or renal denervation, but not captopril injection, markedly attenuated (but did not abolish) hemorrhage-induced VP release. In contrast, none of these manipulations attenuated the VP response in NTS-intact rats. Hemorrhage increased plasma renin activity in control and NTS-lesioned rats, and this response was not altered by renal denervation. In rats with NTS lesions and renal denervation, hemorrhage induced the expression of Fos in hypothalamic magnocellular VP neurons in a pattern similar to that of hemorrhage in intact rats. Collectively, these results indicate that in chronic NTS-lesioned rats an afferent signal arising from the kidneys stimulates VP release during hemorrhage, possibly through renal nerves. However, with the NTS intact or after the selective removal of arterial baroreceptor inputs, such a role for the kidneys is not apparent. Furthermore, in the absence of the NTS and renal nerves, another signal generated by hypotensive hemorrhage continues to stimulate VP neurons.

Regulatory and secondary water intake in rats with lesions of the zona incerta

1976 ◽  
Vol 230 (4) ◽  
pp. 1049-1057 ◽  
Author(s):  
MD Evered ◽  
GJ Mogenson
Keyword(s):  
Water Intake ◽  
Fluid Balance ◽  
Zona Incerta ◽  
Water Losses ◽  
Daily Food Intake ◽  
Excretory Function ◽  
Daily Food ◽  
Daily Water Intake ◽  
Electrolytic Lesions ◽  
Daily Water

Bilateral electrolytic lesions of the zona incerta (ZI) permanently reduced daily water intake of rats by 20-30%. Lesioned rats did not differ from controls in daily food intake, body weight, hematocrit, or serum osmolality, Na+ or K+ levels. The hypodipsia was not caused by changes in water requirements or excretory function or by a nonspecific depression of behavior. Compensatory reductions in water losses maintained fluid balance. Lesioned rats drank as much water as controls in response to intracellular and extracellular dehydration, but unlike controls, appeared to restrict their daily water intake to these regulatory responses. Lesions of the ZI attenuated the ingestion of extra water observed when rats were maintained on a liquid diet adequate to meet fluid requirements, and daily water intake of lesioned but not control rats closely followed changes in water needs. It was concluded that lesions of the ZI reduce daily water intake towards minimal requirements for fluid balance by attenuating secondary drinking (drinking independent of water needs for fluid homeostasis.

scholarly journals Water Intake, Water Balance, and the Elusive Daily Water Requirement

Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1928 ◽  
Author(s):  
Lawrence Armstrong ◽  
Evan Johnson
Keyword(s):  
Water Balance ◽  
Life Stage ◽  
Body Water ◽  
Water Volume ◽  
Published Data ◽  
Water Requirements ◽  
Neuroendocrine Response ◽  
Organ Systems ◽  
Daily Water ◽  
The Brain

Water is essential for metabolism, substrate transport across membranes, cellular homeostasis, temperature regulation, and circulatory function. Although nutritional and physiological research teams and professional organizations have described the daily total water intakes (TWI, L/24h) and Adequate Intakes (AI) of children, women, and men, there is no widespread consensus regarding the human water requirements of different demographic groups. These requirements remain undefined because of the dynamic complexity inherent in the human water regulatory network, which involves the central nervous system and several organ systems, as well as large inter-individual differences. The present review analyzes published evidence that is relevant to these issues and presents a novel approach to assessing the daily water requirements of individuals in all sex and life-stage groups, as an alternative to AI values based on survey data. This empirical method focuses on the intensity of a specific neuroendocrine response (e.g., plasma arginine vasopressin (AVP) concentration) employed by the brain to regulate total body water volume and concentration. We consider this autonomically-controlled neuroendocrine response to be an inherent hydration biomarker and one means by which the brain maintains good health and optimal function. We also propose that this individualized method defines the elusive state of euhydration (i.e., water balance) and distinguishes it from hypohydration. Using plasma AVP concentration to analyze multiple published data sets that included both men and women, we determined that a mild neuroendocrine defense of body water commences when TWI is ˂1.8 L/24h, that 19–71% of adults in various countries consume less than this TWI each day, and consuming less than the 24-h water AI may influence the risk of dysfunctional metabolism and chronic diseases.

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