Ethanol consumption and resistance are inversely related to neuropeptide Y levels

Genetic linkage analysis of rats that were selectively bred for alcohol preference identified a chromosomal region that includes the neuropeptide Y (NPY) gene. Alcohol-preferring rats have lower levels of NPY in several brain regions compared with alcohol-non-preferring rats. We therefore studied alcohol consumption by mice that completely lack NPY as a result of targeted gene disruption. Here we report that NPY-deficient mice show increased consumption, compared with wild-type mice, of solutions containing 6%, 10% and 20% (v/v) ethanol. NPY-deficient mice are also less sensitive to the sedative/hypnotic effects of ethanol, as shown by more rapid recovery from ethanol-induced sleep, even though plasma ethanol concentrations do not differ significantly from those of controls. In contrast, transgenic mice that overexpress a marked NPY gene in neurons that usually express it have a lower preference for ethanol and are more sensitive to the sedative/hypnotic effects of this drug than controls. These data are direct evidence that alcohol consumption and resistance are inversely related to NPY levels in the brain.

Diagnosis and management of rhinitis: complete guidelines of the Joint Task Force on Practice Parameters in Allergy, Asthma and Immunology. American Academy of Allergy, Asthma, and Immunology

This document contains complete guidelines for diagnosis and management of rhinitis developed by the Joint Task Force on Practice Parameters in Allergy, Asthma and Immunology, representing the American Academy of Allergy, Asthma and Immunology, the American College of Allergy, Asthma and Immunology and the Joint Council on Allergy, Asthma and Immunology. The guidelines are comprehensive and begin with statements on clinical characteristics and diagnosis of different forms of rhinitis (allergic, non-allergic, occupational rhinitis, hormonal rhinitis [pregnancy and hypothyroidism], drug-induced rhinitis, rhinitis from food ingestion), and other conditions that may be confused with rhinitis. Recommendations on patient evaluation discuss appropriate use of history, physical examination, and diagnostic testing, as well as unproven or inappropriate techniques that should not be used. Parameters on management include use of environmental control measures, pharmacologic therapy including recently introduced therapies and allergen immunotherapy. Because of the risks to patients and society from sedation and performance impairment caused by first generation antihistamines, second generation antihistamines that reduce or eliminate these side effects should usually be considered before first generation antihistamines for the treatment of allergic rhinitis. The document emphasizes the importance of rhinitis management for comorbid conditions (asthma, sinusitis, otitis media). Guidelines are also presented on special considerations in patients subsets (children, the elderly, pregnancy, athletes and patients with rhinitis medicamentosa); and when consultation with an allergist-immunologist should be considered.

Algorithm for the diagnosis and management of asthma: a practice parameter update: Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma and Immunology, the American College of Allergy, Asthma and Immunology, and the Joint Council of Allergy, Asthma and Immunology

This algorithm on the diagnosis and treatment of asthma is intended to complement and update the previously published Practice Parameters for the Diagnosis and Treatment of Asthma. Both documents were developed by the Joint Task Force on Practice Parameters, representing the AAAAI, ACAAI, and the JCAAI. The authors of this asthma algorithm have attempted to include all the elements essential for the diagnosis and care of patients with asthma. Every effort was made to keep the algorithm clear and concise, yet thorough and complete (Fig 1). Each component of the algorithm is elaborated further in a brief annotation. For further discussion, the reader is referred to the more extensive Practice Parameters for the Diagnosis and Treatment of Asthma.

Joint Task Force Algorithm and Annotations for Diagnosis and Management of Rhinitis

The algorithm and text annotations in this document are intended to assist clinical decision making about patients who present with symptoms of rhinitis. This document complements the Executive Summary of Joint Task Force Practice Parameters for Diagnosis and Management of Rhinitis (Ann Allergy, Asthma, Immunol 1998; 81:463-468) and Diagnosis and Management of Rhinitis: Complete Guidelines of the Joint Task Force on Practice Parameters in Allergy, Asthma and Immunology (Ann Allergy, Asthma, Immunol 1998;81:478-578). The Joint Task Force on Practice Parameters in Allergy, Asthma and Immunology is co-sponsored by the American Academy of Allergy, Asthma and Immunology, the American College of Allergy, Asthma and Immunology and the Joint Council of Allergy, Asthma and Immunology.

Conditioning method dramatically alters the role of amygdala in taste aversion learning

Although an important role for the amygdala in taste aversion learning has been suggested by work in a number of laboratories, results have been inconsistent and interpretations varied. The present series of studies reevaluated the role of the amygdala in taste aversion learning by examining the extent to which conditioning methods, testing methods and lesioning methods, influence whether amygdala lesions dramatically affect conditioned taste aversion (CTA) learning. Results indicated that when animals are conditioned with an intraoral (I/O) taste presentation, lesions of amygdala eliminate evidence of conditioning whether animals are tested intraorally or with a two-bottle solution presentation. Dramatic effects of amygdala lesions on CTA learning were seen whether lesions were made electrolytically or using an excitotoxin. In contrast, when animals were conditioned using bottle presentation of the taste, electrolytic lesions attenuated CTAs but did not eliminate them, and excitotoxic lesions had no effect. These results are consistent with the hypothesis that neural structures critical for CTA learning may differ depending on the extent to which the method of conditioned stimulus delivery incorporates a response component.

Central infusion of glucagon-like peptide-1-(7-36) amide (GLP-1) receptor antagonist attenuates lithium chloride-induced c-Fos induction in rat brainstem

Central infusion of glucagon-like peptide-1-(7-36) amide (GLP-1) and intraperitoneal (i.p.) injection of lithium chloride (LiCl) produce similar patterns of c-Fos induction in the rat brain. These similarities led us to assess the hypothesis that neuronal activity caused by i.p. injection of LiCl involves activation of central GLP-1 pathways. We therefore determined if third-ventricular (i3vt) infusion of a GLP-1 receptor antagonist would block LiCl-induced c-Fos expression in the brainstem. Relative to rats pretreated with i3vt infusion of vehicle, pretreatment with the potent GLP-1 receptor antagonist, des His1 Glu9 exendin-4 (10.0 microgram), significantly attenuated LiCl-induced (76 mg/kg; i.p.) c-Fos expression in several brainstem regions, including the area postrema, the nucleus of the solitary tract, and the lateral parabrachial nucleus. While central infusion of des His1 Glu9 exendin-4 also blocked GLP-1-induced (10.0 microgram) anorexia and c-Fos expression, the antagonist produced no independent effects on food intake or c-Fos expression. These results suggest that LiCl-induced c-Fos expression in the rat brainstem is mediated, at least in part, by GLP-1 receptor signaling.

Forebrain contribution to the induction of a brainstem correlate of conditioned taste aversion. II. Insular (gustatory) cortex

The induction of c-Fos-like immunoreactivity (c-FLI) in the intermediate division of the nucleus of the solitary tract (iNTS) has been shown to be a cellular correlate of the behavioral expression of a conditioned taste aversion (CTA). To further define neuroanatomical structures and pathways that contribute to this cellular response and to CTA learning in general, electrolytic lesions of insular (gustatory) cortex (IC) were combined with immunostaining for c-FLI. Rats were given either unilateral or bilateral electrolytic lesions of insular cortex or 'sham' operations. Following surgery, 'paired' animals were given a single conditioning trial consisting of intraoral infusion of 5-ml 0.15% sodium-saccharin followed by injection with LiCl (0.15 M, 20 ml/kg, i.p.) while 'unpaired' controls received a non-contingent saccharin-LiCl presentation. Rats with bilateral lesions showed no behavioral evidence of having acquired a CTA. Increases in c-FLI in iNTS were evident, but reduced, relative to 'sham' animals. Rats with unilateral-lesions displayed a CTA by rejecting the saccharin, although increases in c-FLI on the side of the iNTS ipsilateral to the lesion were reduced relative to that seen in 'sham' animals. A comparison of these results with those obtained after amygdala lesions supports the conclusion that amygdala and insular cortex are necessary, but not sufficient, for the behavioral expression of a CTA.

Effects of food deprivation on conditioned taste aversions in rats

Food deprivation increases the rewarding effects of self-administered drugs such as psychomotor stimulants and benzodiazepines. These drugs also possess aversive properties and can produce conditioned taste aversions (CTA). Because drug-seeking behavior is most likely affected by both the rewarding and aversive properties of drugs, we hypothesize that food deprivation might also attenuate a drug's aversive consequences. The CTAs induced by three different drugs (amphetamine, chlordiazepoxide, and LiCl) were assessed separately. Male Long-Evans rats were assigned to one of two feeding conditions: restricted (maintained at 80% of free-feeding body weight), or nonrestricted (with ad lib food). Both groups received CTA training, consisting of an intraoral infusion of a novel saccharin solution (10 min) followed immediately by one of two i.p. injections: paired rats received drug, and unpaired rats received a similar volume of saline. After 10 days of ad lib food access, saccharin was presented to all rats again, and the latency to reject the tastant was used as an index of CTA learning. The rats that had been food restricted at the time of conditioning exhibited attenuated CTAs relative to those that had not been deprived. These differences were seen only when a rewarding drug (amphetamine or chlordiazepoxide) and not when a nonrewarding drug (LiCl) was used as the unconditioned stimulus. In a separate experiment, we established that this effect is apparent only when the deprivation period precedes conditioning rather than precedes testing. The present results indicate that food deprivation modulates the acquisition of a CTA induced by amphetamine or chlordiazepoxide, but not LiCl.

Infant salt preference and mother's morning sickness

Evidence for an association between early pregnancy sickness and offspring salt (NaCl) preference has been obtained from studying offspring as young adults. To determine whether effects on NaCl preference are expressed in infancy, the present study examined 16-week-old infants whose mothers reported either little or no vomiting (N = 15) or frequent moderate to severe vomiting (N = 14) during the first 14 weeks of their pregnancy. The infants' oral-motor facial reactions to each solution and their relative intakes of distilled water and 0.1m and 0.2m NaCl were used as measures of preference. Infants of mothers who reported no or mild symptoms had a significantly lower relative intake of salt solutions than infants whose mothers reported moderate to severe symptoms (p < 0.01). The former infants also showed a greater number of aversive facial responses when given 0.2m NaCl (p < 0.05). Taken together, these findings support the hypothesis that maternal dehydration, induced by moderate to severe vomiting during pregnancy, can lead to enhanced salt preference in offspring. They also provide a potential explanation for some of the variability encountered when human infants are tested for their salt preference.

Oral glucocorticosteroid-sparing effect of budesonide administered by Turbuhaler: a double-blind, placebo-controlled study in adults with moderate-to-severe chronic asthma. Pulmicort Turbuhaler Study Group

OBJECTIVE

To determine the ability of budesonide via an inhaler (Pulmicort Turbuhaler; Astra Draco AB) to replace oral glucocorticosteroids (GCSs) in adult subjects with moderate-to-severe asthma.

DESIGN

Double-blind, randomized, and placebo-controlled study, with parallel groups.

SETTING

Multicenter study in outpatient setting.

PARTICIPANTS

Eighty men and 79 women, aged 20 to 69 years, with moderate-to-severe asthma and a mean FEV1 of 58.3% predicted normal. All subjects were receiving oral GCS treatment and 79% of subjects were also receiving inhaled beclomethasone dipropionate (BDP). The mean daily doses of prednisone at baseline, including converted dose of BDP, for the placebo, budesonide 400 microg, and budesonide 800 microg, respectively, were 19.7 mg, 19.5 mg, and 18.7 mg.

MEASUREMENTS AND INTERVENTIONS

After a 2-week baseline period, subjects entered a 20-week treatment period, during which the oral dose of prednisone was reduced by forced down-titration at 2-weekly intervals.

RESULTS

Subjects receiving 400 microg or 800 microg bid of budesonide achieved a significantly greater reduction (82.9% and 79.0% respectively) in oral GCS dose compared with placebo-treated subjects (27%; p<0.001). Two thirds of the subjects receiving budesonide were able to achieve sustained oral corticosteroid cessation, compared with 8% in the placebo group. Additionally, both doses of budesonide resulted in significant improvement in results of pulmonary function tests and asthma symptoms scores, and a significant decrease in the use of bronchodilator therapy. The mean plasma cortisol levels before and after adrenocorticotropic hormone stimulation increased most toward the normal range in the budesonide-treated groups compared with placebo-treated subjects.

CONCLUSION

Budesonide administered via Turbuhaler has a significant oral GCS-sparing capacity with maintained or improved asthma control in adult subjects with moderate-to-severe asthma.

Learned tolerance to ethanol-induced c-Fos expression in rats

With c-Fos immunoreactivity as a marker for neural activity, we examined whether environmental cues associated with ethanol injection influence the expression of tolerance to ethanol-induced c-Fos activation. Over 24 training days, male Long-Evans rats received ethanol injection (2.5 g/kg) in one environment and saline injection in a different environment. Relative to rats that received ethanol for the first time, ethanol-induced c-Fos expression in the paraventricular nucleus of the hypothalamus (PVN) and the locus coeruleus (LC) was significantly reduced in rats that had received multiple prior ethanol administrations. However, tolerance was partially reversed when ethanol was given in the saline-paired, rather than the ethanol-paired, environment. Results suggest that tolerance to ethanol, as indexed by c-Fos expression in the PVN and the LC, is mediated in part by Pavlovian conditioned responses to cues that predict ethanol administration.

Dopamine and sodium appetite: antagonists suppress sham drinking of NaCl solutions in the rat

Sodium (Na) ingestion in rats depleted of Na is a strong, motivated behavior that is enhanced further when depleted rats are sham drinking. Dopamine plays a critical role in motivation, including reward associated with consumption of palatable tastes. The present studies assessed the role of dopamine in real and sham drinking of NaCl solutions after Na depletion with the diuretic furosemide (10 mg/kg). Dopamine (D2) receptor antagonists were evaluated (Haloperidol [0.1 mg/kg] and raclopride [0.2 mg/kg]), for their effects on sham and real drinking of 0.3 M NaCl. Sham drinking was markedly reduced by both antagonists whereas real drinking was unaffected. These effects did not appear to be due to malaise or suppression of motor behavior because drug-treated animals were able to increase ingestion substantially when offered less concentrated NaCl (0.1 M). These results suggest that the positive motivating properties of NaCl stimulation in depleted, sham-drinking rats are mediated by central D2 receptors.

Use of an anti-IgE humanized monoclonal antibody in ragweed-induced allergic rhinitis

BACKGROUND

Increased serum levels of antigen-specific IgE are often associated with allergic respiratory disorders. RhuMAb-E25, a recombinant humanized monoclonal antibody, decreases free serum IgE by forming biologically inactive immune complexes with free IgE.

OBJECTIVE

We hypothesized that rhuMAb-E25 would decrease total serum IgE and reduce symptoms.

METHODS

Two hundred forty subjects were enrolled into five groups to determine the safety, tolerance, and efficacy of repeated administration of rhuMAb-E25 in adults with ragweed-induced allergic rhinitis and to explore the pharmacodynamic relationship of rhuMAb-E25 and IgE. One hundred eighty-one subjects received an initial intravenous loading dose (day 0, 1 month before ragweed season), followed by administration of rhuMAb-E25 (in mg/kg body weight) of 0.15 mg/kg subcutaneously, 0.15 mg/kg intravenously, or 0.5 mg/kg intravenously on days 7, 14, 28, 42, 56, 70, and 84. A subcutaneous placebo group and an intravenous placebo group were included. The total evaluation time included the 84-day treatment period, followed by a 42-day observation period.

RESULTS

Adverse events were mild, and no differences were observed in the rates between the three active and two placebo treatment groups. Ragweed-specific IgE levels correlated with symptom scores. RhuMAb-E25 decreased serum free IgE levels in a dose- and baseline IgE-dependent fashion. However, only 11 subjects had IgE levels that were suppressed to undetectable levels (< or = 24 ng/ml), a sample too small to demonstrate significant differences and clinical efficacy. Thus the case for efficacy was not proven. Nonetheless, the study confirms that it is safe to repeatedly administer rhuMAb-E25 over a period of months.

CONCLUSIONS

Because rhuMAb-E25 decreased serum free IgE in a dose-dependent fashion and because symptom scores correlated with antigen-specific IgE levels, the results suggest that if given in adequate doses, rhuMAb-E25 should be an effective therapy for allergic diseases.

Dopamine and sodium appetite: antagonists suppress sham drinking of NaCl solutions in the rat

Sodium (Na) ingestion in rats depleted of Na is a strong, motivated behavior that is enhanced further when depleted rats are sham drinking. Dopamine plays a critical role in motivation, including reward associated with consumption of palatable tastes. The present studies assessed the role of dopamine in real and sham drinking of NaCl solutions after Na depletion with the diuretic furosemide (10 mg/kg). Dopamine (D2) receptor antagonists were evaluated (Haloperidol [0.1 mg/kg] and raclopride [0.2 mg/kg]), for their effects on sham and real drinking of 0.3 M NaCl. Sham drinking was markedly reduced by both antagonists whereas real drinking was unaffected. These effects did not appear to be due to malaise or suppression of motor behavior because drug-treated animals were able to increase ingestion substantially when offered less concentrated NaCl (0.1 M). These results suggest that the positive motivating properties of NaCl stimulation in depleted, sham-drinking rats are mediated by central D2 receptors.

Ethanol-induced c-Fos expression in rat lines selected for low and high alcohol consumption

Selectively bred rat lines, developed to model genetic contributions to alcohol abuse, include the Indiana alcohol-preferring (P) and alcohol-nonpreferring (NP) lines, and the Alko-Alcohol (AA) and Alko-Nonalcohol (ANA) lines. Preferring and nonpreferring lines were compared in their response to intraperitoneal injection of either ethanol or isotonic saline using c-Fos expression as a marker of neuronal activity. Although line differences were noted in several brain regions, the principal finding was that alcohol-nonpreferring lines (NP and ANA) displayed greater c-Fos expression in the locus coeruleus (LC) relative to the alcohol-preferring lines (P and AA) following injection of 3.0 g ethanol/kg. These data point to the LC as an area which may play a role in the differences in voluntary ethanol consumption between rat lines genetically bred for low and high ethanol preference.

Development of the enhanced neural response to NaCl in Fischer 344 rats

To examine the development of strain differences in the response of the chorda tympani nerve (CT) to NaCl, integrated CT responses to NaCl were recorded from Wistar and F344 rats between 15 and 36 days old. NaCl responses before and after the application of amiloride were expressed relative to 0.5 M NH4Cl as a standard. At 15-17 days old, there were no significant strain differences in the magnitude of NaCl responses. Strain differences emerged at 21-23 days old with responses of F344 rats significantly higher than those of Wistars; these differences became more pronounced at 34-36 days old. Amiloride significantly reduced responses to NaCl at all ages and eliminated any differences between the strains. Changes in neural responsiveness correspond with the emergence of the behavioral expression of F344 salt aversion.

Central infusion of GLP-1, but not leptin, produces conditioned taste aversions in rats

Leptin (ob protein) and glucagon-like peptide-1-(7-36) amide (GLP-1) are peptides recently proposed to be involved in the regulation of food intake. Although the ability of exogenous leptin and GLP-1 to modulate consummatory behavior is consistent with the suggestion that these peptides are endogenous regulatory agents, central administration of these peptides may have aversive side effects, which could explain the anorexia. In the present experiment, exposure to a saccharine taste was immediately followed by central administration of leptin or GLP-1 to determine if these drugs could produce a conditioned taste aversion (CTA) in rats. At doses equated for producing comparable reductions in short-term food intake, GLP-1, but not leptin, generated a robust CTA. Although leptin caused no aversion, this peptide was the only drug to cause relatively long-term reductions in food consumption (16 h) and body weight (24 h). Hence, the results indicate that central GLP-1 produces aversive side effects, and it is argued that these nonspecific effects may explain the anorectic actions of GLP-1.

Prevalence of human seminal plasma hypersensitivity among symptomatic women

BACKGROUND

Experience with human seminal plasma hypersensitivity in the last decade has led to increased physician awareness of symptoms consistent with human seminal plasma sensitization in women. Incidence and prevalence of human seminal plasma hypersensitivity in women are unknown.

OBJECTIVE

A questionnaire survey was distributed to determine the prevalence of human seminal plasma hypersensitivity among a population of women suspected of having this disorder.

METHODS

A questionnaire designed to elicit age, symptoms, duration of symptoms, number of sexual partners, time to onset of symptoms after first human seminal plasma exposure, onset of symptoms after first intercourse, recent gynecologic procedures, history of atopy, vaginitis, food or drug allergy and family history of atopy was distributed to 1,073 women who suspected they had symptoms consistent with human seminal plasma hypersensitivity. Women were considered "possible" for human seminal plasma hypersensitivity if they reported two or more symptoms consistent with localized or systemic human seminal plasma hypersensitivity. Women were considered "probable" for disease if they fulfilled the "ultimate criterion" defined as complete prevention of symptoms with a condom. Women with "possible" localized or systemic human seminal plasma hypersensitivity who had persistent symptoms despite use of a condom served as cohort control groups.

RESULTS

Two-hundred sixty-six women reported symptoms "possible" for human seminal plasma hypersensitivity (88 localized and 178 systemic). When the "ultimate criterion" was applied, 130 (46 localized and 84 systemic) of the 266 women were identified as having "probable" human seminal plasma hypersensitivity. The responses to most of the questions from each group were very similar. A significantly shorter time interval to symptom onset after initial human seminal plasma exposure was more common for women with "probable" localized human seminal plasma hypersensitivity compared with their cohort control group (49 months versus 108 months; P < .02) whereas a significantly increased number of women with "probable" systemic human seminal hypersensitivity gave positive food allergy histories compared with their cohort control group (31 versus 20; P < .05). Atopy did not appear to be a risk factor for human seminal plasma hypersensitivity.

CONCLUSIONS

Evaluation of women with symptoms suggestive of human seminal plasma hypersensitivity using a validated questionnaire indicates that this disorder is more common than previously recognized.

Forebrain contribution to the induction of a brainstem correlate of conditioned taste aversion: I. The amygdala

The induction of c-Fos-like immunoreactivity (c-FLI) in the intermediate division of the nucleus of the solitary tract (iNTS) has been shown to be a reliable cellular correlate of the acquisition and/or behavioral expression of a conditioned taste aversion (CTA). To begin to define neuroanatomical structures and pathways that contribute to this cellular response and to CTA learning in general, electrolytic lesions of the amygdala were combined with immunostaining for c-FLI. Rats were given either unilateral or bilateral electrolytic lesions of the amygdala or "sham' operations. Following surgery "paired' animals were given a single conditioning trial consisting of intraoral infusion of 5 ml 0.15% sodium-saccharin followed by injection with LiCl (0.15 M, 20 ml/kg, i.p.) while "unpaired' controls received a non-contingent saccharin-LiCl presentation. When tested, unilateral-lesioned rats displayed a CTA by rejecting the saccharin, but increases in c-FLI were evident only on the side of the iNTS contralateral to the lesion. Rats with bilateral lesions showed no evidence of having acquired a CTA and no increase in c-FLI in iNTS relative to unpaired controls. These findings support involvement of amygdala in CTA learning and suggest that a lateralized connection between amygdala and iNTS is necessary for the conditioned c-FLI which is induced by exposure to a conditioned aversive taste.

Central infusions of leptin and GLP-1-(7-36) amide differentially stimulate c-FLI in the rat brain

Recently, glucagon-like peptide-1-(7-36) amide (GLP-1) and leptin have been implicated in the regulation of food intake. In the present study, we compared the effects of third ventricular administration (i3vt) of leptin (3.5 micrograms) and GLP-1 (10.0 micrograms) on short-term food intake and c-Fos-like immunoreactivity (c-FLI) in hypothalamic, limbic, and hindbrain areas in the rat. Relative to controls, infusion of leptin or GLP-1 (3 h before lights off) significantly reduced food intake over the first 2 h in the dark phase (53 and 63%, respectively). In different rats, infusion of leptin or GLP-1 elevated c-FLI in the paraventricular hypothalamus and central amygdala. Furthermore, leptin selectively elevated c-FLI in the dorsomedial hypothalamus, whereas GLP-1 selectively elevated c-FLI in the nucleus of the solitary tract, area postrema, lateral parabrachial nucleus, and arcuate hypothalamic nucleus. The fact that most of the c-FLI after leptin or GLP-1 administration was observed in separate regions within the central nervous system (CNS) suggests different roles for leptin and GLP-1 in the CNS regulation of food intake and body weight.

c-Fos induction in rat brainstem in response to ethanol- and lithium chloride-induced conditioned taste aversions

When consumption of a novel taste (conditioned stimulus; CS) is followed by exposure to a toxin, organisms will avoid consumption of that taste in the future. This learned response, known as a conditioned taste aversion (CTA), can be demonstrated using a variety of drugs, including lithium chloride (LiCl) and ethanol. c-Fos immunohistochemistry was used to examine neural activation in the rat brainstem associated with drug administration and with a CS taste previously paired with these drugs. Relative to saline controls, animals injected with either LiCl (76 mg/kg) or ethanol (3.5 g/kg) displayed greater c-Fos expression in area postrema, nucleus of the solitary tract (NTS), and lateral parabrachial nucleus. At these doses, LiCl- and ethanol-injected groups did not differ from each other. For establishing a CTA, intraoral infusion of a 0.15% saccharin solution was followed by injection of either LiCl or ethanol. Both LiCl and ethanol produced quantitatively similar CTAs. Relative to unpaired control groups, saccharin paired with either drug induced significant c-Fos expression in NTS. Thus, like LiCl, ethanol and tastes that have become aversive by virtue of their association with ethanol activate brainstem regions hypothesized to play a role in CTA learning.