Chronic ethanol ingestion-induced changes in open-field behavior and oxidative stress in the rat

Whole body vibration ameliorates anxiety-like behavior and memory functions in 30 months old senescent male rats

Whole body vibration (WBV) is a form of passive exercise that offers an alternative physical training to aged individuals with limitations in their physical and mental capabilities. The aim of the present study was to explore the therapeutic potential of five weeks of WBV on anxiety-like behaviors as well as learning and memory abilities in senescent thirty months old rats. Animals were exposed to 5 min vibration twice per day, five times per week during the five consecutive weeks. Pseudo WBV treated animals served as controls. After five weeks of WBV treatment, animals were tested for anxiety-like behavior by the open field test and for spatial and object memory functions by the novel and spatial object recognition tests, respectively. As a result, anxiety-like and exploratory behaviors were significantly improved in the WBV treated group compared to the pseudo WBV group. Furthermore, WBV treatment increased discrimination performance in both spatial and object memory function testing. These results indicate that WBV treatment in thirty months old rats seems to have comparable beneficial effects on age-related emotional and cognitive performance as what has been reported in younger age groups.

Effects of Long-Term Moderate Intensity Exercise on Cognitive Behaviors and Cholinergic Forebrain in the Aging Rat

Physical exercise is now generally considered as a strategy to maintain cognitive abilities and to prevent age-related cognitive decline. In the present study, Wistar rats were subjected to moderate intensity treadmill exercise for 6 months prior to sacrifice at 12-, 24- and 32-month of age. This chronic physical intervention was tested on motility in the Open field (OF). Cognitive functions were measured in the Morris water maze (MWM) for spatial learning and in the Novel object recognition (NOR) tests. Since learning and memory are closely associated with cholinergic forebrain function ChAT fiber density after exercise training was assessed in hippocampus, and motor- and somatosensory cortical areas. Furthermore, quantification of ChAT-positive fiber aberrations as a neuropathological marker was also carried out in these brain areas. Our results show that in OF chronic exercise maintained horizontal locomotor activity in all age groups. Rearing activity, MWM and notably NOR performance were improved only in the 32-months old animals. Regarding cholinergic neuronal innervation, apart from a general age-related decline, exercise increased ChAT fiber density in the hippocampus CA1 area and in the motor cortex notably in the 32-months group. Massive ChAT fiber aberrations in all investigated areas which developed in senescence were clearly attenuated by exercise. The results suggest that moderate intensity chronic exercise in the rat is especially beneficial in advanced age. In conclusion, chronic exercise attenuates the age-related decline in cognitive and motor behaviors as well as age-related cholinergic fiber reduction, reduces malformations of cholinergic forebrain innervation.

Chronic ethanol intake-induced changes in open-field behavior and calcium/calmodulin-dependent protein kinase IV expression in nucleus accumbens of rats: naloxone reversal

AIM

To investigate the effects of chronic ethanol intake on the locomotor activity and the levels of calcium/calmodulin-dependent protein kinase IV (CaM kinase IV) in the nucleus accumbens (NAc) of rats. Simultaneously, the effects of nonselective opioid antagonist (naloxone) on the CaM kinase IV expression in the NAc and ethanol consumption of rats were also observed.

METHODS

Ethanol was administered in drinking water at the concentrations of 6% (v/v), for 28 d. The locomotor activity of rats was investigated in the open-field apparatus. CaM kinase IV levels in the NAc were analyzed using Western blotting.

RESULTS

Rats consuming ethanol solution exhibited a significant decrease of ambulation activity, accompanied by a reduced frequency of explorative rearing in an open-field task on d 7 and d 14 of chronic ethanol ingestion, whereas presumed adaptation to the neurological effects of ethanol was observed on d 28. Chronic ethanol intake elicited a significant decrease of the CaM kinase IV expression in the nuclei, but not in the cytoplasm of the NAc on d 28. Naloxone treatment significantly attenuated ethanol intake of rats and antagonized the decrease of CaM kinase IV in the nuclei of NAc neurons. The cytosolic CaM kinase IV protein levels of the NAc also increased in rats exposed to ethanol plus naloxone.

CONCLUSION

Chronic ethanol intake-induced changes in explorative behavior is mediated at least partly by changes in CaM kinase IV signaling in the nuclei of the NAc, and naloxone attenuates ethanol consumption through antagonizing the downregulation of CaM kinase IV in the NAc.

Dietary restriction protects against chronic-ethanol-induced changes in exploratory behavior in Wistar rats

Chronic ethanol intake causes various types of neural damage and behavioral impairments, probably acting through oxidative stress and excitotoxicity, while dietary restriction is considered by some authors to protect the central nervous system from these kinds of damage. In the present study, a factorial experimental design was used to investigate the effects of chronic ethanol and dietary restriction treatments, associated or not, on Wistar rats' exploratory behavior, spatial memory aspects and cortical and hippocampal acetylcholinesterase (AChE) activity. Dietary restriction lasted for the whole experiment, while ethanol treatment lasted for only 3 weeks. Despite the short ethanol treatment duration, for two behavior categories assessed, moving and rearing, an interaction was observed between the effects of chronic ethanol and dietary restriction. There were no significant differences in AChE activities among the groups. Cerebellar neural nitric oxide synthase (nNOs) activity was measured as a first step to assess oxidative stress. Dietary restriction significantly reduced NO formation. The present results indicate that dietary restriction might exert a protective effect against chronic-ethanol-induced changes in exploratory behavior. It is hypothesized that the mechanisms underlying this protection can involve prevention of oxidative stress.

Sensitivity and tolerance to autonomic effects of ethanol in adolescent and adult rats during repeated vapor inhalation sessions

BACKGROUND

It is during adolescence that most drinkers initiate ethanol intake, with some of this use being excessive. One possible contributor to the increased ethanol consumption often seen during adolescence in humans and in various animal models is age differences in ethanol sensitivity and tolerance. The present study examined the impact of age on ethanol-related alterations in the autonomic nervous system.

METHODS

Sensitivity to the initial ethanol challenge and chronic tolerance as well as acute and protracted withdrawal-like phenomena were assessed in male adolescent and adult Sprague-Dawley rats, using implanted telemetry probes with ethanol delivered via vapor inhalation.

RESULTS

Both ages showed similar ethanol-induced tachycardia and activity suppression; however, adolescents were found to be more sensitive than adults to the hypothermic effect of ethanol, data opposite other results from our laboratory and elsewhere using intragastric intubations or intraperitoneal administrations of ethanol. Although little tolerance to ethanol's tachycardic or activity suppressant effects was seen after repeated ethanol inhalation sessions, chronic tolerance to ethanol's hypothermic effect developed faster in adults than in adolescents. A withdrawal-like syndrome, characterized by bradycardia and hypoactivity, typically emerged during the dark phase of the diurnal cycle after ethanol vapor exposure sessions. These effects were observed in animals of both ages, with the bradycardic effect more pronounced in adolescents.

CONCLUSIONS

In contrast to results indicating that adolescents may be less sensitive than adults to ethanol's hypothermic effect when ethanol is administered via bolus injection/intubation, adolescents appear more sensitive and develop tolerance to ethanol's hypothermic effects more slowly than adults when ethanol is administered at a more moderate rate via vapor inhalation.

Effects of ethanol and folic acid consumption during pregnancy and lactation on basal enzymatic secretion in the duodenal juice of offspring rats

OBJECTIVES

Studies on duodenal juice enzyme activities were carried out on suckling Wistar rats born to dams given ethanol during gestation and suckling. The results were compared with offspring of dams given diets containing no ethanol. Comparisons were also made with offspring of dams given ethanol and folic acid supplementation to observe whether a folate supplement could sufficiently reverse the negative effect of ethanol consumption.

METHODS

The dams were fed increased amounts of ethanol (5% to 20%, vol/vol) in tap water for 4 wk. The maximum quantity, 20% ethanol, was given to the dams during pregnancy and lactation. Offspring animals were randomized into three groups: control (CG), ethanol treated (EG), and ethanol plus folic acid (EFG).

RESULTS

Body weight at birth and at 21 d after birth and pancreatic weight were lower in offspring after ethanol treatment. Folic acid supplement increased these parameters in the EFG. Under basal conditions, decreases in amylase, lipase, and chymotrypsin activities in the duodenal juice after ethanol treatment were detected. Serum and urine amylase activities also decreased in the EG and EFG. These changes were different in the ethanol-treated progenitors. In these progenitors, ethanol treatment increased serum amylase levels. In the offspring, amylase activities in the EFG decreased with respect to the CG; however, an increase in the EG was observed. In dams the folic acid supplement did not significantly alter the serum amylase activities. Lipase and chymotrypsin activities in the EFG were similar to those in the EG. An increase of serum and urine amylase in the EFG with respect to the EG was found.

CONCLUSIONS

Our findings indicated that, under basal conditions, ethanol treatment during gestation and lactation negatively affects the digestive function in offspring. The effects of ethanol were slightly attenuated in rats supplemented with folic acid for amylase activities. Although extrapolation from animal studies can be tenuous, the present findings may explain the use of folic acid in the prevention of damage induced by ethanol to increase the amylase levels to physiologic concentrations.

Protective effect of folic acid against oxidative stress produced in 21-day postpartum rats by maternal-ethanol chronic consumption during pregnancy and lactation period

In this paper we show the protective effect of folic acid on oxidative stress in offspring caused by chronic maternal ethanol consumption during pregnancy and the lactation period. Glutathione reductase (GR) specific activity was assayed in liver and pancreas of offspring and mothers. In the offspring, these tissues were also assayed for markers of oxidative damage to lipids and proteins. The results show that ethanol exposure during pregnancy and lactation increased the specific activity of GR in tissues of the mothers (32-34% increase) as well as in the liver of their progeny (24%). Thiobarbituric acid reactive substances (TBARS) were also increased in the liver and pancreas of 21-day-old rats (37- and 54%, respectively). Alcohol also increased the amount of carbonyl groups in proteins in both tissues. These measures of ethanol-mediated oxidative stress were mitigated when pregnant rats were treated with folic acid concomitantly to ethanol administration. The antioxidant capacity of folic acid seems to be involved in its protective effect. The results obtained in the present work suggest that folic acid may be useful in the prevention of damage and promotion of health of the progeny of ethanol-treated rats.

Effects of combined exposure to aluminium and ethanol on food intake, motor behaviour and a few biochemical parameters in pubertal rats

Combined daily administration of aluminium chloride (260 mg/kg, oral) and ethanol (2 g/kg, oral), to pubertal male rats for 30 days was found to significantly decrease food intake, body weight gain and serum protein levels. Spontaneous motor activity and rota-rod motor coordination were also significantly impaired. Acetylcholinesterase activity was significantly diminished in the cerebrum and cerebellum. The results obtained in the present study are suggestive of a potentiation of cholinotoxic effects of the two compounds when administered together. Thus, when combined, ethanol may increase pubertal rat's susceptibility to the toxic effects of aluminium.

Behavioral and immune changes in v-Ha-ras transgenic mice

Transgenic mice (Oncomice) with an activated v-Ha-ras oncogene under the control of the mouse mammary tumor virus promoter develop mammary tumors. We wondered if the expression of the v-Ha-ras oncogene product would induce changes in mice behavioral activity, that could be associated with alterations in their immune system. Behavior was evaluated in an open field study considering line crossings and rears. Oncomice consistently showed less activity than FVB mice. Lieber-DeCarli diet decreased both types of activity in both strains. Cocaine treatment increased line crossings in both strains. Oncomice spleen and thymus cell supernatants contained higher levels of IL-2. Oncomice serum had higher levels of IL-1alpha. Our results suggest a direct association between higher levels of IL-1alpha and lower open field activity. Therefore, we can infer that the increased level of IL-1alpha found in Oncomice, could have a key role in oncogene induced immune and behavioral changes, and could be a requirement to facilitate its transforming activity.