PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Drinking Behavior”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,585 records · Page 88Linked to original sources

Schedule-induced polydipsia: the role of oral and plasma factors.

To appreciate the contribution of oral and post-absorptive factors in the control of schedule-induced polydipsia (SIP), body fluid balance was determined at various times into the 4 hr session. Although dehydrated at the start of the session, rats quickly returned to normal balance which was maintained, despite excessive intake, by a brisk water diuresis. Plasma, as measured via the T-1824 technique, was also normal. Gastric infusion of water following each pellet delivery failed to eliminate the polydipsia despite marked hemodilution, whereas, oral infusion of equivalent amounts of water completely abolished the phenomenon. Taken together, these results suggest that SIP is mediated by oropharyngeal rather than hydration controls.

Animals↗

Competitive behavior: intact male rats but not hyperdefensive males with medial hypothalamic lesions share water with females.

Male hooded rats with medial hypothalamic lesions or sham lesions were given tests of defensiveness toward an experimenter. The 8 lesioned males with the highest defensiveness scores and 7 sham-lesioned males were each placed in a double cage with a single intact female. For each pair of rats, food was continuously present but water was available for only 1 hr/day through a single water spout. Beginning on the fifth day of water deprivation, each pair of animals was given a 4-min water competition test on 3 consecutive days. Competition for water was created by placing a plastic ring over the hole in the cage where the water spout entered the cage. The ring restricted access to the spout to a single animal and was put in place 5 min before water was given. One hr following the competition test, each pair of animals was given access to a single unencumbered spout for a 1-hr period. Rats with medial hypothalamic lesions drank significantly more and initiated more aggression than their female cagemates during the 4-min competition tests. Sham-lesioned rats neither drank significantly more nor were more aggressive than their female cagemates. These results are consistent with previous observations indicating that the aggressiveness of rats with medial hypothalamic lesions can be elicited by a competition situation.

Aggression↗

Development of circadian rhythms in rats with lesions of serotonergic system.

In order to assess the role of the serotonergic system in the development of overt circadian rhythms in the rat, serotonin neurons in the brain were destroyed either by thermocoagulation of the median raphe (MRL) or by an intracerebroventricular injection of the neurotoxin, 5,7-dihydroxytryptamine (DHT). The reductions in serotonin content induced by two manipulations with MRL and DHT were 41% and 100% in the striatum, 40% and 66% in the hypothalamus, and 62% and 88% in the hippocampus, respectively. Neither manipulation eliminated the expression of circadian rhythms in corticosterone (CS) secretion, locomotor activity and drinking behavior, and changed the phase relationship in the overt CS rhythm. Also, 5,7-DHT treatments did not significantly affect the free-running period in locomotor activity. However, the emergence of CS circadian rhythm was delayed for one week in both MRL and DHT groups compared to the intact control ones. These results suggested that a serotonergic system would not be essential for the generation of the endogenous rhythm and the photoentrainment of overt circadian rhythms, but seems to participate in the only development of CS rhythms during the early stage of life.

Aging↗

Amino acid and NaCl appetite, and LHA neuron responses of lysine-deficient rat.

Rats' preferences for amino acids and NaCl in their drinking behavior were noted when they were fed either a control diet of gluten plus 20% purified egg protein, or (same rats, different time) a lysine-deficient diet. In control, the order of the rats' preferences was arginine greater than saline greater than monosodium L-glutamate (MSG, umami) greater than glycine greater than water greater than threonine greater than histidine greater than lysine. When fed a lysine-deficient diet the order of preference was lysine greater than saline greater than MSG greater than glycine greater than threonine greater than water greater than arginine greater than histidine. To relate neural activity with preference for amino acids and NaCl, activity of lateral hypothalamic (LHA) neurons was recorded during ingestion of MSG, lysine, arginine, glycine, saline, glucose, or water by the control and lysine-deprived condition, following a different cue tone. When the diet was lysine deficient, some neurons responded specifically to lysine ingestion. More neurons responded nondifferentially during licking in control, and responded to lysine, but fewer to other amino acid ingestion during lysine deficiency. Responses to cue tone were associated with those during licking. The present results suggest that preference for deficient amino acids might be mediated in the LHA.

Amino Acids↗

Effects of hydrational state on ingestion in infant rats: is dehydration the only ingestive stimulus?

The physiological stimulus for deprivation-enhanced ingestion was studied in developing rats. During an overnight deprivation period, continuous gastric infusions of isotonic saline or milk were made to 6- and 15-day-old rat pups in order to preferentially maintain hydrational or hydrational and nutritional status, respectively. Pups' ingestion was then studied in oral-infusion tests. In 6-day-old pups that received either milk or saline infusions, ingestion was depressed relative to intake in pups that were simply deprived. But in 15-day-old pups, only milk infusions reduced intake. These findings suggest that the increased ingestion stimulated by deprivation in pups less than a week of age results primarily from dehydration, and thus that nutrient-related feeding does not emerge until later in development.

Animals↗

Brain aldehyde dehydrogenase activity in rat strains with high and low ethanol preferences.

The activity of aldehyde dehydrogenase in subcellular fractions of whole brain homogenates from the AA and ANA rat strains developed respectively for high and low ethanol preferences has been studied. No significant strain or sex differences between naive AA and ANA rats were found. In ethanol-experienced rats some strain and sex differences were found, the most consistent being higher enzyme activity in AA females than in males both with aliphatic and aromatic aldehyde substrates. However, contrary to previous findings no relation between brain aldehyde dehydrogenase activity and drinking behavior was found in the AA and ANA rat strains.

Aldehyde Dehydrogenase↗

Neuropeptide K suppresses feeding in the rat.

We studied the effects of neuropeptide K (NPK), a 36 amino acid residue peptide of the tachykinin family, on latency to onset of feeding and cumulative 1 and 2 h food intake in three experimental paradigms. Intraperitoneal injection of NPK (1.25 and 3.14 nmol) to food-deprived rats delayed the onset of feeding and significantly decreased the cumulative food intake. Intraperitoneal injection of NPK (1.25 and 3.14 nmol) to water-deprived rats produced no effect on subsequent drinking behavior. Similarly, intraperitoneal injection of NPK (3.14 nmol) 15 min before onset of the dark phase (of the light-dark cycle) significantly delayed the occurrence of ingestive behavior and the cumulative food intake was markedly suppressed. Furthermore, administration of NPK intraperitoneally (0.5-3.14 nmol) 15 min before intraventricular (i.c.v.) injection of neuropeptide Y (NPY 0.47 nmol) to satiated rats significantly suppressed NPY-induced feeding and delayed the onset of ingestive behavior. However, when administered centrally prior to NPY injection, NPK delayed the onset of feeding response only. Collectively, these findings show that NPK can acutely and consistently suppress feeding behavior.

Animals↗

The neuroanatomical and neurovascular organization of normal fetal hypothalamic explants in the third cerebral ventricle of Brattleboro rats with homozygous diabetes insipidus.

This investigation has combined microangiography, immunocytochemistry, coupled with transmission and scanning electron microscopy to discuss the neuroanatomical interactions that occur in the brains of Brattleboro rats with diabetes insipidus, following stereotaxic placement of normal fetal hypothalamic fragments into the third cerebral ventricle. Following surgical placement of 17 day post-coitus hypothalamic fragments, host rats with chronic autosomal homozygous diabetes insipidus were killed and their brains were prepared for analysis. A significant degree of explants (68%) flourished and grew in the lumen of the third cerebral ventricle of recipient hosts. Explants were rapidly invaded by host vessels from two routes. Vessels arose from the underlying mantle plexus of portal capillaries which remained fenestrated in the lower one-third of the explants and developed neurovascular (neurohemal) zones. The second source of vessels arose from bed capillaries of the adjacent paraventricular nucleus and adjacent hypothalamus. In contrast to vessels arising from the contact zone, these latter vessels remained unfenestrated. Small clusters of immunocytochemically positive neurons (neurophysin positive) were seen throughout the explants. Numerous healthy magnocellular neurons harboring numerous dense core vesicles and exhibiting multiple axosomatic and axodendritic synapses were seen throughout the neuropil of explants. Axon profiles were noted to terminate upon the abluminal basal lamina of perivascular spaces surrounding fenestrated capillaries in the lower one third of explants. None of the host animals exhibited physiological return to normal parameters of urine output, drinking behavior, and/or urine osmolarity. However the growth and development of explants in the third cerebral ventricle of DI hosts coupled with the emergence of bonafide neurovascular zones supports a potential anatomical substrate for the central delivery of neuropeptide hormones in this experimental model.

Animals↗

Olfactory connections of substantia innominata and nucleus of the horizontal limb of the diagonal band in the rat: an electrophysiological study.

Extracellular unit recordings performed on 113 spontaneously discharging neurons in the substantia innominata-nucleus of the horizontal limb of the diagonal band region revealed that 46 (41%) were transsynaptically discharged or inhibited following stimulation of the main and accessory olfactory bulb (MOB, AOB) and the prepyriform cortex (PPC). A significantly greater number of cells were responsive to MOB and PPC than to AOB shocks. Eight (7%) neurons were antidromically invaded following MOB volleys. These findings suggest that the MOB has functional reciprocal connections with the 'ventral striatum', a region which can function, presumably as a nodal point for convergence of visual, gustatory and olfactory information relevant to feeding and drinking behavior.

Amygdala↗

Differential control of operant and consummatory licking in rats.

The failure of rats to optimize their behavior when drinking from two retractable spouts available for single licks was analyzed. The rats were trained in an apparatus where the contacted spout was withdrawn after completion of a lick and the other spout was presented. After 5 days of such forced spout alternation training the animals continued to emit 2.7 instead of the optimum 1.0 lick per spout presentation (LPSP). With water available in one spout only the average LPSP at the empty spout dropped to 1.2 and increased to 3.6 at the water containing spout. It is argued that the operant licks at the dry spout approach the ideal value of 1.0 LPSP whereas the number of LPSPs at the water spout is increased by the consummatory nature of licking triggered by the presence of water in the oral cavity.

Animals↗

Differential regulation of melanin-concentrating hormone gene expression in distinct hypothalamic areas under osmotic stimulation in rat.

Melanin-concentrating hormone and associated peptides represent a novel peptide neuronal system that may be involved in the control of water homeostasis in mammals. We have examined the effect of 24 h dehydration or salt-loading over a period of six days, on melanin-concentrating hormone messenger RNA levels in rat brains by using complementary methods of Northern blotting and in situ hybridization histochemistry. In response to one to six day salt-loading regimen, hypothalamic melanin-concentrating hormone messenger RNA content in male or female rats decreased by two to three-fold. Levels of melanin-concentrating hormone messenger RNA in the hypothalamus were also dramatically decreased following dehydration in female rats whereas contrasting responses were noted in male rats. In addition, no significant variation in the low levels of melanin-concentrating hormone gene transcripts in medulla pons and cortex was found after osmotic stimulus. In agreement with Northern blot data, in situ hybridization studies revealed that the majority of the melanin-concentrating hormone-expressing neurons in the anterior part of the lateral hypothalamus of dehydrated or salt-loaded rats expressed lower amounts of melanin-concentrating hormone messenger RNAs than those found in control rats. Interestingly, less variation was found in the posterior part of the lateral hypothalamus. Furthermore few clusters of cells, located in zona incerta and near the internal capsula and fornix, increased their contents in melanin-concentrating hormone messenger RNA in salt-loaded but not in dehydrated rats suggesting that melanin-concentrating hormone gene expression may be regulated differently by various osmotic stimuli. Finally, diurnal variations in melanin-concentrating hormone messenger RNA contents were observed in normal and dehydrated rats with highest levels around 22.00 h and lowest levels during daylight hours. However, the up-regulation of melanin-concentrating hormone gene activity at night was found lower in dehydrated rats than in control animals suggesting that osmotic stress may interfere with the generation of the diurnal pattern of melanin-concentrating hormone messenger RNA expression. Altogether, our results indicate that osmotic stimulations lead to a selective and conspicuous inhibition of melanin-concentrating hormone gene activity in the whole hypothalamus of rat. We suggest that the melanin-concentrating hormone neuronal system plays an important role in integration processes relative to nocturnal regulation of water homeostasis and drinking behavior.

Animals↗

Ontogeny of lateral preoptic unit activity in rats.

Extracellular single unit recordings were made from units within the lateral preoptic area (LPO) of infant rats from 1 day of age through 31 days of age (postweaning). The rats were anesthetized with dial-urethane and basal (spontaneous) spike rates were recorded for 10--20 min. The rats also received pain-arousal stimulation (tail-pinch and sc injection of formalin solution), and osmotic stimulation (sc or ip injection of hyperosmotic NaCl or sucrose solutions). LPO units were spontaneously active in neonatal rats; however, basal spike rates increased during development. Also increasing during development was the percentage of LPO units which displayed alteration of spike rate in response to hyperosmotic injections (osmosensitive). However, LPO units were found that were responsive to severe pain-arousal stimulation at all ages tested. The developmental changes in LPO unit activity characteristics paralleled the morphological development of LPO neurons and the development of osmotically induced drinking behaviors.

Aging↗