Depressed Appetite Research Articles

Feed intake, growth and ionoregulation in Atlantic salmon ( Salmo salar L.) smolts in relation to dietary addition of a feeding stimulant and time of seawater transfer

Feed intake, growth and ionoregulation of Atlantic salmon ( Salmo salar L.) were studied in fish fed diets either with or without squid extract supplementation in combination with transfer from fresh water to seawater (SW) at different times during parr–smolt transformation (10 April, 3 May and 19 June). Water temperature was held at approximately 8 °C. All groups of fish showed a temporary depression in feeding and growth after SW transfer. The depression was most severe in fish transferred in April, intermediate in fish transferred in May and shortest in fish transferred in June. Nevertheless, squid extract resulted in increased feeding and growth, especially in fish transferred to SW in June, providing evidence that squid extract contains substances that serve as feeding stimulants. The results indicate that there may be a potential to improve SW performance of salmon by adding squid extract to feed. The results also indicate that Atlantic salmon may be transferred to SW over a relatively long period during spring, but to minimise the duration of appetite depression, late transfer may be preferable. Individual feeding rates following short-time SW exposure were not correlated with plasma chloride concentrations in any of the groups, indicating that appetite suppression is not a direct result of osmo-ionoregulatory failure.

Research Communication: Defatted Avocado Pulp Reduces Body Weight and Total Hepatic Fat But Increases Plasma Cholesterol in Male Rats Fed Diets with Cholesterol

The potential use of avocado as a fiber source was evaluated. The total dietary fiber content of fresh avocado fruit of the Ettinger variety was 5.2 g/100 g. Approximately 75% was insoluble, and 25% soluble. The water-holding capacity of dry defatted avocado pulp was similar to that of cellulose, and trypsin inhibitors were not detected. The dietary and metabolic consequences of the avocado pulp were studied in male rats fed normal and hypercholesterolemic diets. Rats consumed semipurified diets containing either avocado pulp as the dietary fiber source or cellulose (control) with or without 10 g/kg cholesterol and 5 g/kg cholic acid. Food consumption and body weight gain were lower in rats fed avocado compared with those fed cellulose. Relative cecum weight was higher in avocado-fed rats. Plasma and hepatic cholesterol levels did not differ in rats fed diets without cholesterol, but plasma cholesterol was greater in avocado-fed than in cellulose-fed rats that consumed cholesterol. Regardless of dietary cholesterol, hepatic total fat levels, as evaluated histologically, but not directly, were lower in avocado-fed rats. These data suggest the presence of an appetite depressant in avocado and that avocado pulp interferes with hepatic fat metabolism.

A Case with Striatocapsular Infarction that Developed Severe Depression which was Successfully Treated with Olanzapine and Paroxetine

Abstract: It is well known that depression can often occur after various kinds of cerebrovascular disorders and that antidepressants including selective serotonin reuptake inhibitor (SSRI) are effective against poststroke depression (PSD). But some cases of PSD, as in the case of endogenous depression, can be treatment‐resistant. Here we report a case that developed severe appetite loss and depression one month after the onset of left‐sided Striatocapsular infarction. The appetite loss was so severe that transnasal nutrition was necessary. Amantadine or sulpiride was administered to him, but neither of them were effective. The maximum tolerable dose of paroxetine gave him slight improvement, but it was not enough. Recently, it has been reported that a combination of olanzapine, which is a kind of multi‐acting receptor targeted agent (MARTA), and fluoxetine, a kind of SSRI, demonstrated superior efficacy for treatment‐resistant depression (TRD) compared to either agent alone. In our case, a combination of olanzapine and paroxetine showed a drastic improvement in appetite loss and depression. The result suggested that a combination of MARTA and SSRI can be as effective in treatment‐resistant PSD as in endogenous TRD.

Cholecalciferol-induced bait shyness in possums (Trichosurus vulpecula)

Cholecalciferol (vitamin D3) is used in a variety of bait formulations to control populations of the brushtail possum (Trichosurus vulpecula), an introduced pest that seriously damages and threatens primary production and native biota in New Zealand. In cage trials, possums readily ate sublethal baits containing either an estimated LD15 or LD40 dose of cholecalciferol, leading to a depression of appetite that lasted for 7-15 days. When lethal quantities of baits were presented 21-30 days after the initial LD15 or LD40 baits, 40 and 88% of possums survived, respectively, compared with a 21% survival rate among naive possums, and bait consumption was also reduced among survivors of the initial baits. Subsequent switching of the bait base to a gel was partially successful in overcoming bait shyness, killing 40% of one group (formed by pooling the original groups), while switching both the bait type (to gel) and the toxicant (to 1080) resulted in a 63% mortality rate in a second group. By comparison, 95 and 100% of naive groups were killed by cholecalciferol and 1080 gel respectively. Practical measures are identified for both avoiding and overcoming bait shyness based on the use of alternative bait types and toxicants.

Interaction between nutrition and gastrointestinal parasitism in sheep

Effects of gastrointestinal nematode infection on metabolism and nutrient utilisation in sheep are reviewed. Infection induces protein deficiency by increasing the demand for amino acids in the alimentary tract while reducing supply through depression of appetite. Mechanisms through which improved protein nutrition could improve the performance of the host are then discussed. Opportunities for capitalising on such effects are limited by our rudimentary understanding of the cell-mediated immune response in gastrointestinal epithelial tissue. Both resistance of the animal to larval establishment and performance in the face of larval challenge can be enhanced by improved protein nutrition. However, enhanced immune responses may not necessarily be synonymous with improved productivity except at luxurious levels of protein intake, because of apparently competing demands for protein. Such levels of protein nutrition are difficult to achieve in pasture-based systems, because of the protein limiting role of the rumen. Work with protein-protecting tannins to overcome this limitation is discussed. The much more limited evidence for effect of mineral nutrition, particularly copper (Cu), molybdenum (Mo), cobalt (Co) and phosphorus (P), on outcome of larval challenge is also reviewed.

Decreased concentration of plasma leptin in periparturient dairy cows is caused by negative energy balance.

Dairy cows suffer from an intense energy deficit at parturition due to the onset of copious milk synthesis and depressed appetite. Despite this deficit, maternal metabolism is almost completely devoted to the support of mammary metabolism. Evidence from rodents suggests that, during periods of nutritional insufficiency, a reduction in plasma leptin serves to co-ordinate energy metabolism. As an initial step to determine if leptin plays this role in periparturient dairy cows, changes in the plasma concentration of leptin were measured during the period from 35 days before to 56 days after parturition. The plasma concentration of leptin was reduced by approximately 50% after parturition and remained depressed during lactation despite a gradual improvement in energy balance; corresponding changes occurred in the abundance of leptin mRNA in white adipose tissue. To determine whether negative energy balance caused this reduction in circulating leptin, cows were either milked or not milked after parturition. Absence of milk removal eliminated the energy deficit of early lactation, and doubled the plasma concentration of leptin. The plasma concentration of leptin was positively correlated with plasma concentrations of insulin and glucose, and negatively correlated with plasma concentrations of growth hormone and non-esterified fatty acids. In conclusion, the energy deficit of periparturient cows causes a sustained reduction in plasma leptin. This reduction could benefit early lactating dairy cows by promoting a faster increase in feed intake and by diverting energy from non-vital functions such as reproduction.

Carfentanil citrate used as an oral anesthetic agent for brown bears (Ursus arctos).

Carfentanil citrate was given orally to five adult brown bears (Ursus arctos) on 14 separate occasions during the winter and summer to determine effective anesthetic dosages and how season may alter these dosages. Lower blood urea nitrogen:creatinine ratios, depressed appetite, and decreased activity levels in the winter versus summer were reflective of different metabolic states, even though bears were not hibernating in the winter. Doses of carfentanil citrate between 6.0 and 15.2 microg/kg were mixed with 5-10 ml of honey, which the bears licked voluntarily from a spoon. During each anesthetization, respiratory and heart rates, hemoglobin saturation, temperature, electrocardiogram, blood gas values, and level of consciousness were monitored and utilized to determine effective dosages. Mean (+/- SE) dose requirements in the winter were 7.6 +/- 0.4 microg/kg, whereas a greater mean dose of 12.7 +/- 0.5 microg/kg was required in the summer (P < 0.05). After ingestion began, sternal recumbency occurred in an average of 7.5 min (range: 4-11 min), and full restraint and safe handling was achieved in 21 min (range: 8-40 min). At the end of each procedure, naltrexone was given as the reversal agent at a ratio of 100 mg naltrexone per 1 mg carfentanil, with 25% of the dose given i.v. or i.m. and 75% given s.c. Mean reversal time was 6 min after injection of naltrexone (range: 4-9 min). Rapid induction and recovery times and ease of oral administration make carfentanil citrate an effective anesthetic agent for use in brown bears. However, hypoventilation and respiratory acidosis were noted in all bears, and oxygen insufflation is recommended.

NSAIDs action in the CNS

Non-steroidal anti-inflammatory drugs (NSAIDs) are known to relieve pain by acting at the local site of injury, but they have also now been shown to relieve pain by CNS mechanisms. NSAIDs reduce inflammation and pain locally by inhibiting the enzyme cyclooxygenase-2 (COX-2), which inhibits formation of prostaglandin E2 (PGE2). PGE2 increases the sensitivity of peripheral nerves to pain. Scientists at Massachusetts General Hospital in Boston, however, now show that peripheral injury also induces COX-2 expression in the brain and spinal cord, and PGE2 increases the excitability of CNS neurons so that even nonpainful stimuli are perceived as painful, explaining why inflamed tissue feels sensitive and tender. Furthermore, inhibiting COX-2 in the CNS also decreases pain and hypersensitivity. The researchers suggest that targeting the widespread CNS production of COX-2 might more-effectively relieve pain as well as improve secondary symptoms such as lethargy, depression and loss of appetite. The study is in the March 22 issue of Nature.

The association of low serum cholesterol with depression and suicidal behaviours: new hypotheses for the missing link.

Several observational studies indicate that reduction of serum cholesterol levels is related to an increase in violent deaths and suicide but the nature of this possible relationship remains unclear. Many confounding factors, e.g. poor health, depression and loss of appetite may play a role in the apparent relationship between serum cholesterol levels and suicide. Two separate phenomena should be considered: lowering total cholesterol and low total cholesterol. This review considers the evidence from epidemiological studies on serum cholesterol lowering and psychiatric disturbances. The available evidence does not seem to substantiate the view that large-scale intervention to reduce cholesterol concentrations could lead to more violent and aggressive behaviour, and generally greater unhappiness. In recent trials using statin treatment, there were slightly fewer deaths from accidents and suicide in the treated group compared with the placebo group. We believe that clinicians should not be deterred from prescribing cholesterol-lowering drugs, to reduce the risk of death from coronary heart disease, when they are indicated.

Distribution of mRNAs encoding the arylhydrocarbon receptor, arylhydrocarbon receptor nuclear translocator, and arylhydrocarbon receptor nuclear translocator-2 in the rat brain and brainstem.

Dioxin exposure alters a variety of neural functions, most likely through activation of the arylhydrocarbon receptor (AhR) pathway. Many of the adverse effects, including disruption of circadian changes in hormone release and depressed appetite, seem to be mediated by hypothalamic and/or brainstem neurons. However, it is unclear whether these effects are direct or indirect, because there have been no comprehensive studies mapping the expression of components of the AhR pathway in the brain. Therefore, we used a sensitive in situ hybridization histochemical (ISHH) method to map the neural expression of AhR mRNA, as well as those of the mRNAs encoding the AhR dimerization partners, arylhydrocarbon receptor nuclear translocator (ARNT) and ARNT2. We found that AhR, ARNT, and ARNT2 mRNAs were widely distributed throughout the brain and brainstem. There was no neuroanatomic evidence that AhR is preferentially colocalized with ARNT or ARNT2. However, ARNT2, unlike ARNT expression, was relatively high in most regions. The most noteworthy regions in which we found AhR, ARNT, and ARNT2 mRNA were several hypothalamic and brainstem regions involved in the regulation of appetite and circadian rhythms, functions that are disrupted by dioxin exposure. These regions included the arcuate nucleus (Arc), ventromedial hypothalamus (VMH), paraventricular nucleus (PVN), suprachiasmatic nucleus (SCN), nucleus of the solitary tract (NTS), and the dorsal and median raphe nuclei. This neuroanatomic information provides important clues as to the sites and mechanisms underlying the previously unexplained effects of dioxins in the central nervous system.

Physiological roles of tryptophan in pig nutrition.

Tryptophan (TRP) is shown to play original roles in the physiology of pigs. Dietary TRP deficiency induces depression of the appetite leading to reduced growth performance. Brain hydroxy-indoles, including the neurotransmitter serotonin, are closely related to dietary TRP supply. Excess protein, namely large neutral amino acids (LNAA) enhanced the appetite depression, providing some support to a role for plasma TRP:LNAA in the regulation of protein intake through serotonin. Other implications of TRP, as a precursor for serotonin, in the susceptibility of pigs to stress and in their consequences on meat quality were reported. Furthermore, we concluded to a role for TRP in the insulin response to the meal and in tissue sensitivity to insulin. Implications in pig feeding practice are briefly reviewed.

Hypophagia-induced hypometabolism during experimental anaemia in rats

Several investigators have reported a drop in oxygen (O2) consumption (VO2) and body temperature in laboratory animals during normobaric or hypobaric hypoxia. Hypophagia, with normal efficiency of protein utilisation for growth, was also observed. It has recently also been observed that hypometabolism is present during anaemic hypoxia. The present study was designed to test the experimental hypothesis that anaemic hypoxia induces hypometabolism secondary to hypophagia. Episodes of anaemia were created in adult male rats by either blood withdrawal through cardiac puncture (haemorrhagic anaemia) or phenylhydrazine administration (haemolytic anaemia). Haematrocrit, VO2, and food consumption, as indirect estimations of the level of anaemia, energy production, and appetite, respectively, were serially measured in all animals during 7 days (acute experiments) or 17 days (chronic experiments). Positive correlations were found between the three parameters during development of and recovery from anaemia during each anaemic episode. When the amount of food offered to non-anaemic rats was equalised to that freely eaten by anaemic rats, VO2 dropped in the former to almost the level found in the latter. Body composition changed during chronic anaemia because of a decrease in the lipid fraction of the body. The results confirmed the working hypothesis that hypometabolism, which has been considered as an immediate, emergency-type response to both hypoxic and anaemic hypoxia, can be considered as a response secondary to hypophagia because of depressed appetite. How appetite is adapted to the mechanisms which control O2 convection and O2 availability is not known at present.

Collaboration of antibody and inflammation in clearance of rabies virus from the central nervous system.

To investigate the involvement of various cellular and humoral aspects of immunity in the clearance of rabies virus from the central nervous system, (CNS), we studied the development of clinical signs and virus clearance from the CNS in knockout mice lacking either B and T cells, CD8+ cytotoxic T cells, B cells, alpha/beta interferon (IFN-alpha/beta) receptors, IFN-gamma receptors, or complement components C3 and C4. Following intranasal infection with the attenuated rabies virus CVS-F3, normal adult mice of different genetic backgrounds developed a transient disease characterized by loss of body weight and appetite depression which peaked at 13 days postinfection (p.i.). While these animals had completely recovered by day 21 p.i., mice lacking either B and T cells or B cells alone developed a progressive disease and succumbed to infection. Mice lacking either CD8+ T cells, IFN receptors, or complement components C3 and C4 showed no significant differences in the development of clinical signs by comparison with intact counterparts having the same genetic background. However, while infectious virus and viral RNA could be detected in normal control mice only until day 8 p.i., in all of the gene knockout mice studied except those lacking C3 and C4, virus infection persisted through day 21 p.i. Analysis of rabies virus-specific antibody production together with histological assessment of brain inflammation in infected animals revealed that clearance of CVS-F3 by 21 days p.i. correlated with both a strong inflammatory response in the CNS early in the infection (day 8 p.i.), and the rapid (day 10 p.i.) production of significant levels of virus-neutralizing antibody (VNA). These studies confirm that rabies VNA is an absolute requirement for clearance of an established rabies virus infection. However, for the latter to occur in a timely fashion, collaboration between VNA and inflammatory mechanisms is necessary.

The Cholinergic Hypothesis of Neuropsychiatric Symptoms in Alzheimer's Disease

A variety of neuropsychiatric symptoms occur in Alzheimer's disease (AD) including agitation, psychosis, depression, apathy, disinhibition, anxiety, purposeless behavior, and disorders of sleep and appetite. Neuropsychiatric symptoms have been related to cholinergic deficiency and improve after treatment with cholinomimetic agents. Cholinergic drugs are unique among psychotropic agents in exerting disease-specific and broad-spectrum effects. These observations provide the basis for the cholinergic hypothesis of the neuropsychiatric symptoms of AD, suggesting that the cholinergic deficit of AD contributes to the neuropsychiatric symptoms of AD and that cholinomimetic therapy ameliorates the behavioral disturbances accompanying AD.

Pathophysiology of infection with gastrointestinal nematodes in domestic ruminants: recent developments

Infection with gastrointestinal nematodes, particularly Ostertagia species in domestic ruminants, continues to represent an important cause of impaired productivity in temperate parts of the world. The mechanisms responsible for such losses include changes in feed intake, gastrointestinal function, protein, energy and mineral metabolism, and body composition, and were described in detail at the last Ostertagia Workshop (Fox, M.T. 1993. Pathophysiology of infection with Ostertagia ostertagi in cattle. Vet. Parasitol. 46, 143–158). Since then, research into the pathophysiology of infection has focused on three main areas: mechanisms of appetite depression; changes in gastrointestinal function; and alterations in protein metabolism. Studies on the mechanisms responsible for appetite depression in Ostertagia-infected cattle have continued to support a close association between impaired feed intake and elevated blood gastrin concentrations. Alternative explanations will have to be sought, however, to account for the drop in feed intake associated with intestinal parasitism in which blood gastrin levels normally remain unaltered. Such work in sheep, and more recently in laboratory animals, has shown that central satiety signals are associated with inappetance accompanying intestinal infections, rather than changes in peripheral peptide levels. Changes in gastrointestinal function have also attracted attention, particularly the mechanisms responsible for increases in certain gut secretions, notably pepsinogen and gastrin. Elegant experimental studies have established that the gradient in pepsinogen concentration between abomasal mucosa and local capillaries could alone account for the increase in blood concentrations seen in Type 1 ostertagiosis. Additional factors, such as increases in capillary permeability and in surface area, probably contribute to such responses in cases of Type 2 disease. The increase in blood gastrin concentrations that accompanies Ostertagia infections in cattle is associated with the concurrent rise in abomasal pH. However, in sheep, additional factors appear to contribute to the hypergastrinaemia which may occur independent of parasite-induced changes in gastric pH. Alterations in protein metabolism have been well documented in ruminants harbouring monospecific infections with either abomasal or intestinal nematodes. More recently, however, the effects of dual abomasal and intestinal infections have been investigated and demonstrated that the host is able to compensate for impaired abomasal digestion provided that the intestinal parasite burden does not occupy the main site of digestion and absorption in the latter organ. An alternative method of improving the host's protein balance, dietary supplementation, has been shown not only to improve productivity, but also to enhance the innate resistance of susceptible breeds of sheep to Haemonchus and to accelerate the development of immunity to Ostertagia in lambs.

The lateral hypothalamic area revisited: Ingestive behavior

This article discusses the role of the lateral hypothalamic area (LHA) in feeding and drinking and draws on data obtained from lesion and stimulation studies and neurochemical and electrophysiological manipulations of the area. The LHA is involved in catecholaminergic and serotonergic feeding systems and plays a role in circadian feeding, sex differences in feeding and spontaneous activity. This article discusses the LHA regarding dietary self-selection, responses to high-protein diets, amino acid imbalances, liquid and cafeteria diets, placentophagia, “stress eating,” finickiness, diet texture, consistency and taste, aversion learning, olfaction and the effects of post-operative period manipulations by hormonal and other means. Glucose-sensitive neurons have been identified in the LHA and their manipulation by insulin and 2-deoxy- d-glucose is discussed. The effects on feeding of numerous transmitters, hormones and appetite depressants are described, as is the role of the LHA in salivation, lacrimation, gastric motility and secretion, and sensorimotor deficits. The LHA is also illuminated as regards temperature and feeding, circumventricular organs and thirst and electrolyte dynamics. A discussion of its role in the ischymetric hypothesis as an integrative Gestalt concept concludes the review.

Clinical study of chronic renal failure treated with Baoyuan Dahuang Decoction (保元大黄汤)

Chronic renal failure patients (as test group) under treatment by Baoyuan Dahuang Decoction, other 20 cases (as control group) by western medicine, mainly coated aldehyde oxystain, had commonly blood urea nitrogen and creatinine decreased. But among the test group, the hemoglobin increased obviously, the symptons of fatigue, lassitude in loin and legs, lack of appetite, sexual disorder, and mental depression improved markedly (P<0.01), and estradiol, progesterone, testosterone as well as creatine phosphokinase were regulated notably compared with before treatment (P<0.01). Whereas in the control group, the symptoms were not significantly improved, hemoglobin, levels of sex hormones and creatine phosphokinase differed slightly. It is concluded that Baoyuan Dahuang Decoction possesses efficacy to improve chronic renal failure patients’ vitality and ability, the mechanism of which is related to anemia rectification and membrane function.

Appetite depression in sheep experimentally infected with Fasciola hepatica L.

The purpose of this study was to determine the effects of experimental fasciolosis at various stages of development on the daily food intake of sheep. Five male Churra sheep, 4 months of age, were infected orally with 300 Fasciola hepatica metacercariae over a 30 day period. There was a significant increase in serum glutamate dehydrogenase (GLDH) activity from 40 days post-infection and in aspartate aminotransferase (AST) activity from 60 days post-infection. Both enzyme activities reached maximum levels in the serum of infected animals at 80 days and then progressively decreased. Serum gamma-glutamyltransferase (GGT) activity was significantly increased from 80 to 120 days post-infection. Glycaemia was significantly decreased from 60 days post-infection. The average daily food intake was shown to steadily decrease until approximately 100 days. The coincidence of decreased food intake with the period of significant increase, both in AST and GLDH activities, indicated that damage caused around the time of migration of immature flukes through the liver parenchyma may be involved in appetite depression.

Biological basis of grooming behaviour in antelope: the body-size, vigilance and habitat principles

Grooming in ungulates has been shown to be very effective in removing ectoparasites. Ectoparasites, especially ticks, may be costly to an animal's resources in terms of blood removed and depression of appetite. There are two opposing models that address the parasite-control of function of grooming: (1) animals may groom in response to stimulation from parasite bites, whereupon those with the most parasites should groom the most; or (2) animals may groom prophylactically, removing parasites such as ticks before they attach, as a reflection of a central programming or timing mechanism. Based on behavioural observations of Thomson's gazelle, Gazella thomsonii, Grant's gazelle, Gazella granti, impala, Aepyceros melampus, and wildebeest, Cannocheates gnu, in Kenya and at the San Diego Wild Animal Park (SDWAP), both models seemed to apply to different aspects of grooming. Presumably, as a reflection of their increased vulnerability to ectoparasites through a greater body surface to mass ratio (body-size principle), Thomson's gazelle were found to groom more frequently than wildebeest. This corresponds to a reportedly smaller number of ticks per m 2 surface area in Thomson's gazelle. Territorial males groomed less frequently than conspecific females and bachelor males, presumably relfecting their need to remain vigilant over females (vigilance principle). Within-species grooming was less in a low-parasite environment (SDWAP) than in a high-parasite environment (Kenya), reflecting both a decreased exposure to parasites (habitat principle) and a decrease in programmed grooming. Impala, which typically inhabit tick-infested woodland areas, orally groomed themselves more than the size-matched Grant's gazelle comparison species, and also engaged in a unique form of reciprocal allogrooming of the head and neck. That the impala allogrooming may also have a tick-removal function was supported by the finding that impala scratch-groom the head and neck less than Grant's gazelle.

Demise of a neuronal population in huntington's disease and the importance of hyponeuronogenesis

This article discusses the role of the lateral hypothalamic area (LHA) in feeding and drinking and draws on data obtained from lesion and stimulation studies and neurochemical and electrophysiological manipulations of the area. The LHA is involved in catecholaminergic and serotonergic feeding systems and plays a role in circadian feeding, sex differences in feeding and spontaneous activity. This article discusses the LHA regarding dietary self-selection, responses to high-protein diets, amino acid imbalances, liquid and cafeteria diets, placentophagia, “stress eating,” finickiness, diet texture, consistency and taste, aversion learning, olfaction and the effects of post-operative period manipulations by hormonal and other means. Glucose-sensitive neurons have been identified in the LHA and their manipulation by insulin and 2-deoxy-d-glucose is discussed. The effects on feeding of numerous transmitters, hormones and appetite depressants are described, as is the role of the LHA in salivation, lacrimation, gastric motility and secretion, and sensorimotor deficits. The LHA is also illuminated as regards temperature and feeding, circumventricular organs and thirst and electrolyte dynamics. A discussion of its role in the ischymetric hypothesis as an integrative Gestalt concept concludes the review.