scholarly journals Adolescent rats show estrous cycle-mediated sex-differences in extinction of conditioned fear

2020 ◽  
Author(s):  
Christina J Perry ◽  
Despina E Ganella ◽  
Ly Dao Nguyen ◽  
Xin Du ◽  
Katherine D Drummond ◽  
...  
Keyword(s):  
Anxiety Disorders ◽  
Conditioned Fear ◽  
High Plasma ◽  
Female Rats ◽  
Adolescent Male ◽  
Adult Males ◽  
Preclinical Research ◽  
Male And Female ◽  
Male And Female Rats ◽  
Estradiol Levels

AbstractAnxiety disorders are more prevalent in females than males, and frequently emerge during adolescence. Despite this, preclinical research commonly focuses on adult males. Here we use Pavlovian fear conditioning and extinction in adolescent male and female rats to understand sex- and age-dependent processes relevant to anxiety disorders. In experiment 1, 35-day-old male and female rats were exposed to 6 pairings of a conditioned stimulus (CS, a tone) with an aversive unconditioned stimulus (US, a footshock). The next day they were extinguished in a contextually distinct chamber, via 60 presentations of the CS without the US. Extinction recall was tested 24 hours later in the extinction context. Estrous phase was monitored by cytology on vaginal smears taken 1 hour after each behavioral session. In experiment 2, male and female rats were given sham surgery or gonadectomy at 21 days of age. They were then trained and tested as for experiment 1. We observed that females in proestrus or met/diestrus during extinction showed delayed extinction and impaired extinction recall the next day compared to males. Ovariectomy enhanced extinction for female rats, but orchidectomy delayed extinction for males. Plasma analyses showed that met/di/proestrus phases were associated with high estradiol levels. These findings suggest that high plasma estradiol levels impair extinction for adolescent females. While these results contradict what is observed in adult animals, they are consistent with the prevalence of anxiety disorders observed in females. Our findings have important implications for understanding and treating anxiety in adolescents, particularly where treatment involves extinction-based therapies.

INDUCTION OF GOITRE BY PTU OR KClO4 IN MALE AND FEMALE RATS. EFFECT OF GONADECTOMY

1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia
Keyword(s):  
Iodine Content ◽  
High Plasma ◽  
Disc Electrophoresis ◽  
Female Rats ◽  
Male Rats ◽  
Adult Rats ◽  
Male And Female ◽  
Glucose Levels ◽  
Male And Female Rats ◽  
Tsh Levels

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.

Time-dependent sensitization of antipsychotic effect in adolescent male and female rats

2017 ◽  
Vol 328 ◽  
pp. 186-194 ◽  
Author(s):  
Xiaojing Ding ◽  
Xiaonan Li ◽  
Qing Shu ◽  
Ruiyong Wu ◽  
Gang Hu ◽  
...  
Keyword(s):  
Time Dependent ◽  
Female Rats ◽  
Adolescent Male ◽  
Male And Female ◽  
Antipsychotic Effect ◽  
Male And Female Rats

Sex- and age-dependent differences in the hormone and drinking responses to water deprivation

2020 ◽  
Vol 318 (3) ◽  
pp. R567-R578 ◽  
Author(s):  
Susana Quirós Cognuck ◽  
Wagner L. Reis ◽  
Marcia S. Silva ◽  
Gislaine Almeida-Pereira ◽  
Lucas K. Debarba ◽  
...  
Keyword(s):  
Water Deprivation ◽  
Plasma Concentrations ◽  
Female Rats ◽  
Male Rats ◽  
Ang Ii ◽  
Adult Males ◽  
Adaptive Responses ◽  
Male And Female ◽  
Male And Female Rats ◽  
Female Wistar Rats

Maintenance of the volume and osmolality of body fluids is important, and the adaptive responses recruited to protect against osmotic stress are crucial for survival. The objective of this work was to compare the responses that occur in aging male and female rats during water deprivation. For this purpose, groups of male and female Wistar rats aged 3 mo (adults) or 18 mo (old) were submitted to water deprivation (WD) for 48 h. The water and sodium (0.15 M NaCl) intake, plasma concentrations of oxytocin (OT), arginine vasopressin (AVP), corticosterone (CORT), atrial natriuretic peptide (ANP), and angiotensin II (ANG II) were determined in hydrated and water-deprived animals. In response to WD, old male and female rats drank less water and saline than adults, and both adult and old females drank more water and saline than respective males. Dehydrated old animals displayed lower ANG II plasma concentration and CORT response compared with the respective normohydrated rats. Dehydrated adult males had higher plasma ANP and AVP as well as lower CORT concentrations than dehydrated adult females. Moreover, plasma OT and CORT levels of old female rats were higher than those in the dehydrated old male rats. Relative expression of ANG II type 1 receptor mRNA was decreased in the subfornical organ of adult and old male rats as well as adult female rats in response to WD. In conclusion, the study elucidated the effect of sex and age on responses induced by WD, altering the degree of dehydration induced by 48 h of WD.

Taurine's effects on cocaine reward in adolescent male and female rats

2017 ◽  
Vol 171 ◽  
pp. e4
Author(s):  
Ugochukwu Akpara ◽  
Rina Liang ◽  
Avery Villa-Gonzalez ◽  
Denzel Harrris ◽  
Adel Elzanie ◽  
...  
Keyword(s):  
Female Rats ◽  
Adolescent Male ◽  
Male And Female ◽  
Male And Female Rats ◽  
Cocaine Reward

scholarly journals Effects of nicotine exposure on oral methamphetamine self-administration, extinction, and drug-primed reinstatement in adolescent male and female rats

2020 ◽  
Vol 209 ◽  
pp. 107927 ◽  
Author(s):  
Zachary R. Harmony ◽  
Erin M. Alderson ◽  
Israel Garcia-Carachure ◽  
Laurence D. Bituin ◽  
Cynthia A. Crawford
Keyword(s):  
Female Rats ◽  
Adolescent Male ◽  
Nicotine Exposure ◽  
Self Administration ◽  
Male And Female ◽  
Male And Female Rats

GONADOTROPHIN PATTERNS IN MALE AND FEMALE RATS: PLASMA LH AND FSH AT VARIOUS AGES EVALUATED BY THE METHOD OF PARABIOSIS

1967 ◽  
Vol 56 (1) ◽  
pp. 165-176 ◽  
Author(s):  
Donald C. Johnson
Keyword(s):  
Follicle Stimulating Hormone ◽  
Chorionic Gonadotrophin ◽  
Female Rats ◽  
Adult Males ◽  
Male And Female ◽  
Ovarian Weight ◽  
Average Value ◽  
Male And Female Rats ◽  
Tonic Level ◽  
Males And Females

ABSTRACT Ventral prostates in hypophysectomized male parabiotic partners of intact animals were used to compare the amount of plasma luteinizing hormone (LH) in males and females of various ages. Ovarian weight, histology, and augmentation with chorionic gonadotrophin, in hypophysectomized androgenized females were used to estimate plasma follicle stimulating hormone (FSH) activity in intact adult males and females. In young animals, up to 50 days of age, males apparently have the same amount of plasma LH as females, but older cyclic females produced significantly heavier prostates in their hypophysectomized male partners than did males. The results are consistent with the interpretation that cyclic surges of LH added to a tonic level produced an average value higher for females than males. In contrast, males of all ages and particularly adults, have a significantly greater amount of circulating FSH than females.

scholarly journals Social interaction with an alcohol-intoxicated or cocaine-injected peer selectively alters social behaviors and drinking in adolescent male and female rats

2019 ◽  
Author(s):  
Danielle M. Gamble ◽  
Chloe C. Josefson ◽  
Mary K. Hennessey ◽  
Ashley M. Davis ◽  
Renee C. Waters ◽  
...  
Keyword(s):  
Social Interaction ◽  
Alcohol Drinking ◽  
Social Play ◽  
Social Behaviors ◽  
Ethanol Intake ◽  
Female Rats ◽  
Adolescent Male ◽  
Saccharin Consumption ◽  
Male And Female ◽  
Male And Female Rats

AbstractBackgroundDrinking alcohol is facilitated by social interactions with peers, especially during adolescence. The importance of peer social influences during adolescence on alcohol and substance use have recently received more attention. We have shown that social interaction with an alcohol-intoxicated peer influences adolescent alcohol drinking differently in male and female rats using the demonstrator-observer paradigm. The present set of experiments analyzed the social interaction session to determine behaviors that influence alcohol drinking in adolescent male and female rats.MethodsSpecifically, in experiment one we determined which behaviors were altered during social interaction with an alcohol-intoxicated demonstrator and assessed changes in ethanol intake in adolescent observers. Experiment two examined changes in voluntary saccharin consumption to determine if social interaction with an alcohol-intoxicated demonstrator altered consumption of a palatable solution. In experiment three, we administered a low (5 mg/kg) or high (20 mg/kg) dose of cocaine to the demonstrator and assessed changes in the adolescent observers to determine if social interaction with a ‘drugged’ peer altered social behaviors and voluntary ethanol intake.ResultsWe showed that social interaction with an alcohol-intoxicated demonstrator (1) decreased social play and increased social investigation and social contact in adolescent male and female observers, (2) did not alter non-social behaviors, (3) did not alter saccharin consumption and (4) increased voluntary ethanol intake in adolescent female but not male observers. When the peer was injected with cocaine (1) social play was dose-dependently decreased, (2) there were no changes in other social or non-social behaviors, and (3) voluntary ethanol intake in adolescent male and female observers was unaffected.ConclusionsThe present results are consistent and extend our previous work showing that social interaction with an alcohol-intoxicated peer selectively alters social behaviors and alcohol-drinking in adolescent rats. Females appear to be more sensitive to elevating effects of social interaction on voluntary ethanol consumption.

Concurrent choice between cues for social interaction and amphetamine in adolescent male and female rats

2014 ◽  
Vol 140 ◽  
pp. e246
Author(s):  
Justin R. Yates ◽  
F.C. Jennings ◽  
J.S. Beckmann ◽  
Andrew C. Meyer ◽  
M.T. Bardo
Keyword(s):  
Social Interaction ◽  
Female Rats ◽  
Adolescent Male ◽  
Male And Female ◽  
Male And Female Rats
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