The Experts below are selected from a list of 8769 Experts worldwide ranked by ideXlab platform
Mary S M Pavelka - One of the best experts on this subject based on the ideXlab platform.
-
the role of minerals in food selection in a black howler monkey alouatta pigra population in belize following a major hurricane
American Journal of Primatology, 2012Co-Authors: Alison M Behie, Mary S M PavelkaAbstract:As plants may contain low levels of some minerals including Sodium, copper, and phosphorous, herbivores may become deficient in these nutrients. In 2001, Hurricane Iris hit the Monkey River Forest in Belize causing substantial damage to the food supply of the black howler monkey population (Alouatta pigra) living there. This included an 18-month absence in fruit production and a complete loss of figs that are high in calcium. In this article, we describe the post-hurricane diet of this monkey population and compare the mineral content of food items to each other and to recommendations for non-human primates [NRC 2003]. We also investigate food selection in relation to potentially limiting minerals. Behavioral data from four groups of howlers (2002–2006) and samples of all ingested food items were collected and a sample of 99 plant from 18 food species was analyzed for mineral content. Unexpectedly, the post-hurricane diet contained more mature leaves than new leaves despite the availability of new leaves. Leaves contained higher amounts of minerals than reproductive parts and with the exception of Cecropia peltata stems, plant parts were low in Sodium. Cecropia peltata is a pioneer species that grows following habitat disturbance thus the ingestion of these stems may be a potential mechanism to avoid Sodium Deficiency in this damaged forest. Calcium and zinc were found above recommended values in most food items; however, both positively predicted food selection, which may reflect a difference between their abundance and their bioavailability. However, as mature leaves contained more calcium than other plant parts, their high post-hurricane consumption may also be a response to the absence of figs and the need to find an alternate calcium source. This study highlights how habitat disturbance may affect mineral abundance and the dietary choices of primates. Am. J. Primatol. 74:1054-1063, 2012. © 2012 Wiley Periodicals, Inc.
-
the role of minerals in food selection in a black howler monkey alouatta pigra population in belize following a major hurricane
American Journal of Primatology, 2012Co-Authors: Alison M Behie, Mary S M PavelkaAbstract:As plants may contain low levels of some minerals including Sodium, copper, and phosphorous, herbivores may become deficient in these nutrients. In 2001, Hurricane Iris hit the Monkey River Forest in Belize causing substantial damage to the food supply of the black howler monkey population (Alouatta pigra) living there. This included an 18-month absence in fruit production and a complete loss of figs that are high in calcium. In this article, we describe the post-hurricane diet of this monkey population and compare the mineral content of food items to each other and to recommendations for non-human primates [NRC 2003]. We also investigate food selection in relation to potentially limiting minerals. Behavioral data from four groups of howlers (2002-2006) and samples of all ingested food items were collected and a sample of 99 plant from 18 food species was analyzed for mineral content. Unexpectedly, the post-hurricane diet contained more mature leaves than new leaves despite the availability of new leaves. Leaves contained higher amounts of minerals than reproductive parts and with the exception of Cecropia peltata stems, plant parts were low in Sodium. Cecropia peltata is a pioneer species that grows following habitat disturbance thus the ingestion of these stems may be a potential mechanism to avoid Sodium Deficiency in this damaged forest. Calcium and zinc were found above recommended values in most food items; however, both positively predicted food selection, which may reflect a difference between their abundance and their bioavailability. However, as mature leaves contained more calcium than other plant parts, their high post-hurricane consumption may also be a response to the absence of figs and the need to find an alternate calcium source. This study highlights how habitat disturbance may affect mineral abundance and the dietary choices of primates.
Alan Kim Johnson - One of the best experts on this subject based on the ideXlab platform.
-
The biopsychology of salt hunger and Sodium Deficiency
Pflügers Archiv - European Journal of Physiology, 2015Co-Authors: Seth W. Hurley, Alan Kim JohnsonAbstract:Sodium is a necessary dietary macromineral that tended to be sparsely distributed in mankind’s environment in the past. Evolutionary selection pressure shaped physiological mechanisms including hormonal systems and neural circuits that serve to promote Sodium ingestion. Sodium Deficiency triggers the activation of these hormonal systems and neural circuits to engage motivational processes that elicit a craving for salty substances and a state of reward when salty foods are consumed. Sodium Deficiency also appears to be associated with aversive psychological states including anhedonia, impaired cognition, and fatigue. Under certain circumstances the psychological processes that promote salt intake can become powerful enough to cause “salt gluttony,” or salt intake far in excess of physiological need. The present review discusses three aspects of the biopsychology of salt hunger and Sodium Deficiency: (1) the psychological processes that promote salt intake during Sodium Deficiency, (2) the effects of Sodium Deficiency on mood and cognition, and (3) the sensitization of Sodium appetite as a possible cause of salt gluttony.
-
Role of the lateral parabrachial nucleus in the control of Sodium appetite
American journal of physiology. Regulatory integrative and comparative physiology, 2014Co-Authors: José Vanderlei Menani, Laurival A De Luca, Alan Kim JohnsonAbstract:In states of Sodium Deficiency many animals seek and consume salty solutions to restore body fluid homeostasis. These behaviors reflect the presence of Sodium appetite that is a manifestation of a pattern of central nervous system (CNS) activity with facilitatory and inhibitory components that are affected by several neurohumoral factors. The primary focus of this review is on one structure in this central system, the lateral parabrachial nucleus (LPBN). However, before turning to a more detailed discussion of the LPBN, a brief overview of body fluid balance-related body-to-brain signaling and the identification of the primary CNS structures and humoral factors involved in the control of Sodium appetite is necessary. Angiotensin II, mineralocorticoids, and extracellular osmotic changes act on forebrain areas to facilitate Sodium appetite and thirst. In the hindbrain, the LPBN functions as a key integrative node with an ascending output that exerts inhibitory influences on forebrain regions. A nonspecific or general deactivation of LPBN-associated inhibition by GABA or opioid agonists produces NaCl intake in euhydrated rats without any other treatment. Selective LPBN manipulation of other neurotransmitter systems [e.g., serotonin, cholecystokinin (CCK), corticotrophin-releasing factor (CRF), glutamate, ATP, or norepinephrine] greatly enhances NaCl intake when accompanied by additional treatments that induce either thirst or Sodium appetite. The LPBN interacts with key forebrain areas that include the subfornical organ and central amygdala to determine Sodium intake. To summarize, a model of LPBN inhibitory actions on forebrain facilitatory components for the control of Sodium appetite is presented in this review.
-
opioid mechanisms that mediate the palatability of and appetite for salt in Sodium replete and deficient states
Physiology & Behavior, 2012Co-Authors: Michael J Morris, Alan Kim JohnsonAbstract:Sodium Deficiency reliably produces a robust intake of saline in rats, which is associated with an increased preference for Sodium solutions at hypertonic concentrations that would normally be avoided. The mechanisms underlying the shift to an increased preference for Sodium in the deficient state are not well understood. The current experiments examined the role of opioids on changes of behavioral responses that are modified as a function of body Sodium status by studying the intake of 0.3 M saline in a free access drinking test and by characterizing the changes in orofacial-related behaviors in response to intra-orally delivered 0.3 M NaCl. In intake tests, systemic treatment with morphine and naltrexone respectively, enhanced and attenuated intake of 0.3 M saline in Sodium depleted rats. In taste reactivity tests systemic treatment with morphine significantly decreased negative responses to 0.3 M saline infusions in both Sodium replete and Sodium depleted rats. Systemically administered naltrexone significantly decreased positive hedonic responses to 0.3 M saline infusions only in Sodium depleted rats. These results indicate that peripheral administration of opioid agonists and antagonists alter both hypertonic saline ingestion in a free access situation and taste reactivity responses to hypertonic saline under Sodium replete and deplete conditions. The results indicate that endogenous opioids alter the processing of central information to affect hedonic mechanisms that influence behaviors related to Sodium consumption and palatability.
-
behavioral cross sensitization between morphine induced locomotion and Sodium depletion induced salt appetite
Pharmacology Biochemistry and Behavior, 2009Co-Authors: Michael J Morris, Alan Kim JohnsonAbstract:In general terms, sensitization refers to the capacity of a repetitive stimulus of fixed strength to produce a progressive increase in the magnitude of a response with each stimulation. In the addiction literature cross-sensitization is the capacity of an agent with abuse potential to sensitize a behavioral response induced by another stimulus. In the present experiments we examined the effects of morphine pretreatment on furosemide-induced saline intake and conversely Sodium appetite induction on morphine-induced locomotion. In an initial experiment rats were pretreated with morphine (10 mg/kg, s.c.) or vehicle for 5 days. The rats were then Sodium or sham depleted and 24 h later given a Sodium appetite test. Sodium depleted rats pretreated with morphine increased saline intake compared to depleted rats initially pretreated with vehicle. In a second experiment rats that were previously depleted and repleted of Sodium as compared to sham depleted animals showed enhanced locomotor activity in an open field test when challenged with morphine (1 mg/kg, s.c.). These studies demonstrate that the behavioral responses induced by Sodium Deficiency and morphine treatment cross-sensitize with one another and suggest that common neural substrates underlie the sensitization of behaviors associated with states induced by morphine and Sodium appetite.
Alison M Behie - One of the best experts on this subject based on the ideXlab platform.
-
the role of minerals in food selection in a black howler monkey alouatta pigra population in belize following a major hurricane
American Journal of Primatology, 2012Co-Authors: Alison M Behie, Mary S M PavelkaAbstract:As plants may contain low levels of some minerals including Sodium, copper, and phosphorous, herbivores may become deficient in these nutrients. In 2001, Hurricane Iris hit the Monkey River Forest in Belize causing substantial damage to the food supply of the black howler monkey population (Alouatta pigra) living there. This included an 18-month absence in fruit production and a complete loss of figs that are high in calcium. In this article, we describe the post-hurricane diet of this monkey population and compare the mineral content of food items to each other and to recommendations for non-human primates [NRC 2003]. We also investigate food selection in relation to potentially limiting minerals. Behavioral data from four groups of howlers (2002–2006) and samples of all ingested food items were collected and a sample of 99 plant from 18 food species was analyzed for mineral content. Unexpectedly, the post-hurricane diet contained more mature leaves than new leaves despite the availability of new leaves. Leaves contained higher amounts of minerals than reproductive parts and with the exception of Cecropia peltata stems, plant parts were low in Sodium. Cecropia peltata is a pioneer species that grows following habitat disturbance thus the ingestion of these stems may be a potential mechanism to avoid Sodium Deficiency in this damaged forest. Calcium and zinc were found above recommended values in most food items; however, both positively predicted food selection, which may reflect a difference between their abundance and their bioavailability. However, as mature leaves contained more calcium than other plant parts, their high post-hurricane consumption may also be a response to the absence of figs and the need to find an alternate calcium source. This study highlights how habitat disturbance may affect mineral abundance and the dietary choices of primates. Am. J. Primatol. 74:1054-1063, 2012. © 2012 Wiley Periodicals, Inc.
-
the role of minerals in food selection in a black howler monkey alouatta pigra population in belize following a major hurricane
American Journal of Primatology, 2012Co-Authors: Alison M Behie, Mary S M PavelkaAbstract:As plants may contain low levels of some minerals including Sodium, copper, and phosphorous, herbivores may become deficient in these nutrients. In 2001, Hurricane Iris hit the Monkey River Forest in Belize causing substantial damage to the food supply of the black howler monkey population (Alouatta pigra) living there. This included an 18-month absence in fruit production and a complete loss of figs that are high in calcium. In this article, we describe the post-hurricane diet of this monkey population and compare the mineral content of food items to each other and to recommendations for non-human primates [NRC 2003]. We also investigate food selection in relation to potentially limiting minerals. Behavioral data from four groups of howlers (2002-2006) and samples of all ingested food items were collected and a sample of 99 plant from 18 food species was analyzed for mineral content. Unexpectedly, the post-hurricane diet contained more mature leaves than new leaves despite the availability of new leaves. Leaves contained higher amounts of minerals than reproductive parts and with the exception of Cecropia peltata stems, plant parts were low in Sodium. Cecropia peltata is a pioneer species that grows following habitat disturbance thus the ingestion of these stems may be a potential mechanism to avoid Sodium Deficiency in this damaged forest. Calcium and zinc were found above recommended values in most food items; however, both positively predicted food selection, which may reflect a difference between their abundance and their bioavailability. However, as mature leaves contained more calcium than other plant parts, their high post-hurricane consumption may also be a response to the absence of figs and the need to find an alternate calcium source. This study highlights how habitat disturbance may affect mineral abundance and the dietary choices of primates.
V Bahr - One of the best experts on this subject based on the ideXlab platform.
-
severe hyponatremia due to hypopituitarism with adrenal insufficiency report on 28 cases
European Journal of Endocrinology, 2003Co-Authors: Stefan Diederich, Nils Franzen, V Bahr, W OelkersAbstract:Objective: Severe hyponatremia due to hypopituitarism and adrenal insufficiency can be lifethreatening, and treatment with glucocorticoids is very effective once the diagnosis of the underlying disorder has been made. In our experience, the diagnosis of hypopituitarism in hyponatremic patients is often overlooked. Methods: In a retrospective study we screened the files of 185 patients with severe hyponatremia (, 130 mmol/l) that had been seen in one endocrinological unit of a university hospital between 1981 and 2001 in order to describe the clinical spectrum of patients with hyponatremia and hypopituitarism including secondary adrenal insufficiency. Results: In 139 cases it was possible to clearly ascribe the patients to the pathophysiological groups of (i) primary Sodium Deficiency, (ii) edematous disorders, and (iii) normovolemic disorders including the ‘syndrome of inappropriate secretion of antidiuretic hormone’ (SIADH). Twenty-eight patients with severe ‘normovolemic hyponatremia’ (serum Sodium: 116^7 mmol/l, mean^S.D.) had hypopituitarism and secondary adrenal insufficiency as shown by basal cortisol measurements and dynamic tests of adrenal function. In 25 cases of this group hypopituitarism (mostly due to empty sella, Sheehan’s syndrome and pituitary tumors) had not been recognized previously, and in 12 cases recurrent hyponatremia during previous hospital admissions (up to four times) could be documented. The mean age of these patients (21 women, seven men) was 68 years. The most frequently occurring clinical signs were missing or scanty pubic and axillary hair, pale and doughy skin, and small testicles in the men. Frequent symptoms like nausea and vomiting, confusion, disorientation, somnolence or coma were similar to those in 91 patients with SIADH. Basal serum cortisol levels in the acutely ill state ranged from 20 to 439 nmol/l (mean^S.D.: 157^123), while in 30 other severely hyponatremic patients it ranged from 274 to 1732 nmol/l (732^351 nmol/l). In most patients with hyponatremic hypopituitarism, plasma antidiuretic hormone levels were inappropriately high, probably due to a failure of endogenous cortisol to suppress the hormone in a stressful situation. All patients recovered after low-dose hydrocortisone substitution. Most patients had other pituitary hormone deficiencies and were appropriately substituted subsequently. Conclusions: Hypopituitarism including secondary adrenal insufficiency seems to be a frequently overlooked cause of severe hyponatremia. A high level of suspicion is the best way to recognize the underlying disorder. Treatment with hydrocortisone is very effective.
-
ascorbate and alpha tocopherol depletion inhibit aldosterone stimulation by Sodium Deficiency in the guinea pig
Endocrine Research, 1996Co-Authors: V Bahr, A Redmann, K Mobius, W OelkersAbstract:Ascorbate (Vit. C) and α - tocopherol (Vit. E) are highly concentrated in the adrenal. Both vitamins support steroid synthesis in vitro. Vitamin depletion experiments in guinea pigs were done to study the role in aldosterone synthesis of these antioxidants in vivo. We stimulated aldosterone secretion by Sodium depletion in vitamin depleted animals and compared the effects with those in vitamin replete guinea pigs. We analysed plasma hormone levels and measured ex vivo steroid secretion by isolated adrenal cells and conversion of [3H]deoxycorticosterone to [3H]aldosterone. Fifteen days of a Vit. C - free diet led to very low Vit. C levels in adrenals, liver and plasma, without signs of scurvy. Plasma ACTH and plasma renin activity (PRA) were not influenced. Vit. C depletion abolished a rise of plasma aldosterone and of aldosterone secreted in vitro stimulated by Sodium depletion. The in vitro conversion of [3H]deoxycorticosterone to [3H]aldosterone was reduced and Sodium conservation was impaired by Vit. C...
-
ascorbate depletion prevents aldosterone stimulation by Sodium Deficiency in the guinea pig
European Journal of Endocrinology, 1995Co-Authors: A Redmann, W Oelkers, K Mobius, H H Hiller, V BahrAbstract:The concentration of ascorbic acid (vitamin C) in the adrenal cortex is higher than in any other organ. The role of vitamin C in the adrenal cortex is unknown, but data obtained with bovine adrenocortical cells in vitro favour its role as an antioxidant that especially protects aldosterone synthesis from damaging lipid peroxides. Alternatively, vitamin C could act as part of an auxiliary electron transport system for the last step of aldosterone synthesis. The effects of vitamin C depletion on adrenocortical function cannot be studied in the human for ethical reasons, so we subjected different groups of guinea pigs to vitamin C depletion, Sodium depletion and combined vitamin C and Sodium depletion. Other groups of animals on normal or vitamin C-deficient diets received high-dose adrenocorticotrophin (ACTH) injections for 3 days before sacrifice. Fifteen days of a vitamin C-free diet led to very low vitamin C levels in adrenals, liver and plasma without clear signs of scurvy. At this time, plasma aldosterone and aldosterone secretion by isolated adrenal cells were stimulated significantly by Sodium Deficiency. Simultaneous vitamin C depletion completely abolished the rise in aldosterone in vivo and in vitro, significantly reduced the conversion of [ 3 H]deoxycorticosterone to [ 3 H]aldosterone and impaired renal Sodium conservation. Plasma renin activity (PRA), plasma ACTH and serum potassium were not different in the Sodium-depleted and Sodium plus vitamin C-depleted groups. Sodium depletion did not affect cortisol. Vitamin C depletion led to a significant increase in plasma cortisol without an increase in ACTH, while in vitro secretion of cortisol was slightly decreased. These findings seem to be due to decreased hepatic cortisol metabolism. Three days of ACTH treatment led to a large increase in plasma cortisol and in vitro cortisol secretion, while plasma aldosterone and in vitro aldosterone secretion (and PRA) were greatly suppressed. This effect of ACTH was not changed by vitamin C depletion. In conclusion, our studies have demonstrated for the first time a permissive role of vitamin C in the adaptation of aldosterone secretion and of Sodium excretion to Sodium Deficiency, which is an important physiological function of aldosterone. The molecular mechanisms by which vitamin C is involved in aldosterone synthesis await further studies.
-
ascorbate depletion prevents aldosterone stimulation by Sodium Deficiency in the guinea pig
European Journal of Endocrinology, 1995Co-Authors: A Redmann, W Oelkers, K Mobius, H H Hiller, V BahrAbstract:The concentration of ascorbic acid (vitamin C) in the adrenal cortex is higher than in any other organ. The role of vitamin C in the adrenal cortex is unknown, but data obtained with bovine adrenocortical cells in vitro favour its role as an antioxidant that especially protects aldosterone synthesis from damaging lipid peroxides. Alternatively, vitamin C could act as part of an auxiliary electron transport system for the last step of aldosterone synthesis. The effects of vitamin C depletion on adrenocortical function cannot be studied in the human for ethical reasons, so we subjected different groups of guinea pigs to vitamin C depletion, Sodium depletion and combined vitamin C and Sodium depletion. Other groups of animals on normal or vitamin C-deficient diets received high-dose adrenocorticotrophin (ACTH) injections for 3 days before sacrifice. Fifteen days of a vitamin C-free diet led to very low vitamin C levels in adrenals, liver and plasma without clear signs of scurvy. At this time, plasma aldosterone and aldosterone secretion by isolated adrenal cells were stimulated significantly by Sodium Deficiency. Simultaneous vitamin C depletion completely abolished the rise in aldosterone in vivo and in vitro, significantly reduced the conversion of [3H]deoxycorticosterone to [3H]aldosterone and impaired renal Sodium conservation. Plasma renin activity (PRA), plasma ACTH and serum potassium were not different in the Sodium-depleted and Sodium plus vitamin C-depleted groups. Sodium depletion did not affect cortisol. Vitamin C depletion led to a significant increase in plasma cortisol without an increase in ACTH, while in vitro secretion of cortisol was slightly decreased.(ABSTRACT TRUNCATED AT 250 WORDS)
Arthur D Loewy - One of the best experts on this subject based on the ideXlab platform.
-
Sodium deprivation and salt intake activate separate neuronal subpopulations in the nucleus of the solitary tract and the parabrachial complex
The Journal of Comparative Neurology, 2007Co-Authors: Joel C Geerling, Arthur D LoewyAbstract:Salt intake is an established response to Sodium Deficiency, but the brain circuits that regulate this behavior remain poorly understood. We studied the activation of neurons in the nucleus of the solitary tract (NTS) and their efferent target nuclei in the pontine parabrachial complex (PB) in rats during Sodium deprivation and after salt intake. After 8-day dietary Sodium deprivation, immunoreactivity for c-Fos (a neuronal activity marker) increased markedly within the aldosterone-sensitive neurons of the NTS, which express the enzyme 11-beta-hydroxysteroid dehydrogenase type 2 (HSD2). In the PB, c-Fos labeling increased specifically within two sites that relay signals from the HSD2 neurons to the forebrain--the pre-locus coeruleus and the innermost region of the external lateral parabrachial nucleus. Then, 1-2 hours after Sodium-deprived rats ingested salt (a hypertonic 3% solution of NaCl), c-Fos immunoreactivity within the HSD2 neurons was virtually eliminated, despite a large increase in c-Fos activation in the surrounding NTS (including the A2 noradrenergic neurons) and area postrema. Also after salt intake, c-Fos activation increased within pontine nuclei that relay gustatory (caudal medial PB) and viscerosensory (rostral lateral PB) information from the NTS to the forebrain. Thus, Sodium Deficiency and salt intake stimulate separate subpopulations of neurons in the NTS, which then transmit this information to the forebrain via largely separate relay nuclei in the PB complex. These findings offer new perspectives on the roles of sensory information from the brainstem in the regulation of Sodium appetite.
-
Sodium deprivation and salt intake activate separate neuronal subpopulations in the nucleus of the solitary tract and the parabrachial complex
The Journal of Comparative Neurology, 2007Co-Authors: Joel C Geerling, Arthur D LoewyAbstract:Salt intake is an established response to Sodium Deficiency, but the brain circuits that regulate this behavior remain poorly understood. We studied the activation of neurons in the nucleus of the solitary tract (NTS) and their efferent target nuclei in the pontine parabrachial complex (PB) in rats during Sodium deprivation and after salt intake. After 8-day dietary Sodium deprivation, immunoreactivity for c-Fos (a neuronal activity marker) increased markedly within the aldosterone-sensitive neurons of the NTS, which express the enzyme 11-β-hydroxysteroid dehydrogenase type 2 (HSD2). In the PB, c-Fos labeling increased specifically within two sites that relay signals from the HSD2 neurons to the forebrain—the pre-locus coeruleus and the innermost region of the external lateral parabrachial nucleus. Then, 1–2 hours after Sodium-deprived rats ingested salt (a hypertonic 3% solution of NaCl), c-Fos immunoreactivity within the HSD2 neurons was virtually eliminated, despite a large increase in c-Fos activation in the surrounding NTS (including the A2 noradrenergic neurons) and area postrema. Also after salt intake, c-Fos activation increased within pontine nuclei that relay gustatory (caudal medial PB) and viscerosensory (rostral lateral PB) information from the NTS to the forebrain. Thus, Sodium Deficiency and salt intake stimulate separate subpopulations of neurons in the NTS, which then transmit this information to the forebrain via largely separate relay nuclei in the PB complex. These findings offer new perspectives on the roles of sensory information from the brainstem in the regulation of Sodium appetite. J. Comp. Neurol. 504:379–403, 2007. © 2007 Wiley-Liss, Inc.