scholarly journals Acute Hypophagia and Changes in c-Fos Immunoreactivity in Adolescent Rats Treated with Low Doses of Oxytocin and Naltrexone

2021 ◽  
Vol 11 (1) ◽  
pp. 59
Author(s):  
Mitchell A. Head ◽  
Laura K. McColl ◽  
Anica Klockars ◽  
Allen S. Levine ◽  
Pawel K. Olszewski
Keyword(s):  
Water Intake ◽  
Sucrose Solution ◽  
Basic Research ◽  
Male Rats ◽  
Laboratory Animals ◽  
Adolescent Male ◽  
Low Doses ◽  
Body Weight Reduction ◽  
Adolescent Rats ◽  
Recent Case Report

A recent case report has shown that an adjunctive oxytocin + naltrexone (OT + NTX) treatment promoted more robust hypophagia and body weight reduction than OT alone in an adolescent male with hypothalamic obesity after craniopharyngioma resection. Thus far, there has been no basic research in adolescent laboratory animals that would examine whether the benefit of OT + NTX on appetite extends onto adolescent individuals without surgically induced overeating. Thus, here we examined whether low doses of combined OT + NTX acutely affect post-deprivation intake of energy-dense, standard chow; intake of energy-dense and palatable high-fat high-sugar (HFHS) diet; or calorie-dilute, palaTable 10% sucrose solution without deprivation in adolescent male rats. We assessed whether OT + NTX decreases water intake after water deprivation or produces a conditioned taste aversion (CTA). Finally, by using c-Fos immunoreactivity, we determined changes in activity of feeding-related brain areas after OT + NTX. We found that individual subthreshold doses of OT and NTX decreased feeding induced by energy and by palatability. Significant c-Fos changes were noted in the arcuate and dorsomedial hypothalamic nuclei. The hypophagic doses of OT + NTX did not suppress water intake in thirsty rats and did not cause a CTA, which suggests that feeding reduction is not a secondary effect of gastrointestinal discomfort or changes in thirst processing. We conclude that OT + NTX is an effective drug combination to reduce appetite in adolescent male rats.

scholarly journals Olanzapine treatment of adolescent rats alters adult reward behaviour and nucleus accumbens function

2013 ◽  
Vol 16 (7) ◽  
pp. 1599-1609 ◽  
Author(s):  
Monika Vinish ◽  
Ahmed Elnabawi ◽  
Jean A. Milstein ◽  
Jesse S. Burke ◽  
Jonathan K. Kallevang ◽  
...  
Keyword(s):  
Nucleus Accumbens ◽  
Early Life ◽  
D1 Receptor ◽  
Male Rats ◽  
Adolescent Male ◽  
Long Term Effects ◽  
Nucleus Accumbens Core ◽  
Asymptomatic Patients ◽  
Adolescent Rats

Abstract Antipsychotic drugs are increasingly used in children and adolescents to treat a variety of psychiatric disorders. However, little is known about the long-term effects of early life antipsychotic drug (APD) treatment. Most APDs are potent antagonists or partial agonists of dopamine (DA) D2 receptors; atypical APDs also have multiple serotonergic activities. DA and serotonin regulate many neurodevelopmental processes. Thus, early life APD treatment can, potentially, perturb these processes, causing long-term behavioural and neurobiological sequelae. We treated adolescent, male rats with olanzapine (Ola) on post-natal days 28–49, under dosing conditions that approximate those employed therapeutically in humans. As adults, they exhibited enhanced conditioned place preference for amphetamine, as compared to vehicle-treated rats. In the nucleus accumbens core, DA D1 receptor binding was reduced, D2 binding was increased and DA release evoked by electrical stimulation of the ventral tegmental area was reduced. Thus, adolescent Ola treatment enduringly alters a key behavioural response to rewarding stimuli and modifies DAergic neurotransmission in the nucleus accumbens. The persistence of these changes suggests that even limited periods of early life Ola treatment may induce enduring changes in other reward-related behaviours and in behavioural and neurobiological responses to therapeutic and illicit psychotropic drugs. These results underscore the importance of improved understanding of the enduring sequelae of paediatric APD treatment as a basis for weighing the benefits and risks of adolescent APD therapy, especially prophylactic treatment in high-risk, asymptomatic patients.

scholarly journals Comparison of the VTA and LC response to methylphenidate: a concomitant behavioral and neuronal study of adolescent male rats

2017 ◽  
Vol 118 (3) ◽  
pp. 1501-1514 ◽  
Author(s):  
Tahseen J. Karim ◽  
Cruz Reyes-Vazquez ◽  
Nachum Dafny
Keyword(s):  
Locus Coeruleus ◽  
Ventral Tegmental Area ◽  
Neuronal Activity ◽  
Behavioral Sensitization ◽  
Neuronal Response ◽  
Normal Subjects ◽  
Male Rats ◽  
Adolescent Male ◽  
Adolescent Rats ◽  
Ventral Tegmental

Methylphenidate (MPD), also known as Ritalin, is a psychostimulant used to treat attention deficit hyperactivity disorder. However, it is increasingly being misused by normal adolescents for recreation and academic advantage. Therefore, it is important to elucidate the behavioral and neurophysiological effects of MPD in normal subjects. MPD inhibits the reuptake of catecholamines, mainly found in the ventral tegmental area (VTA) and locus coeruleus (LC). The VTA and LC normally mediate attention, motivation, and drug reward behaviors. Selective neuronal connections between the VTA and LC have been identified implicating regular interaction between the structures. The objective of this study was to compare the neuronal responses of the VTA and LC to MPD in normal adolescent rats. Animals were implanted with permanent electrodes in the VTA and LC, and neuronal units were recorded following acute and repetitive (chronic) saline or 0.6, 2.5, or 10.0 mg/kg MPD exposure. Animals displayed either behavioral sensitization or tolerance to all three doses of MPD. Acute MPD exposure elicited excitation in the majority of all VTA and LC units. Chronic MPD exposure elicited a further increase in VTA and LC neuronal activity in animals exhibiting behavioral sensitization and an attenuation in VTA and LC neuronal activity in animals exhibiting behavioral tolerance, demonstrating neurophysiological sensitization and tolerance, respectively. The similar pattern in VTA and LC unit activity suggests that the two structures are linked in their response to MPD. These results may help determine the exact mechanism of action of MPD, resulting in optimized treatment of patients. NEW & NOTEWORTHY The same dose of 0.6, 2.5, and 10 mg/kg methylphenidate (MPD) elicits either behavioral sensitization or tolerance in adolescent rats. There is a direct correlation between the ventral tegmental area (VTA) and locus coeruleus (LC) neuronal response to chronic MPD exposure. Both the VTA and LC are involved in the behavioral and neurophysiological effects of chronic MPD.

scholarly journals Androgen Affects the Inhibitory Avoidance Memory by Primarily Acting on Androgen Receptor in the Brain in Adolescent Male Rats

2021 ◽  
Vol 11 (2) ◽  
pp. 239
Author(s):  
Md Nabiul Islam ◽  
Yuya Sakimoto ◽  
Mir Rubayet Jahan ◽  
Emi Miyasato ◽  
Abu Md Mamun Tarif ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Inhibitory Avoidance ◽  
Emotional Memory ◽  
Brain Regions ◽  
Male Rats ◽  
Adolescent Male ◽  
Cornu Ammonis ◽  
Adolescent Rats ◽  
The Brain ◽  
Avoidance Memory

Adolescence is the critical postnatal stage for the action of androgen in multiple brain regions. Androgens can regulate the learning/memory functions in the brain. It is known that the inhibitory avoidance test can evaluate emotional memory and is believed to be dependent largely on the amygdala and hippocampus. However, the effects of androgen on inhibitory avoidance memory have never been reported in adolescent male rats. In the present study, the effects of androgen on inhibitory avoidance memory and on androgen receptor (AR)-immunoreactivity in the amygdala and hippocampus were studied using behavioral analysis, Western blotting and immunohistochemistry in sham-operated, orchiectomized, orchiectomized + testosterone or orchiectomized + dihydrotestosterone-administered male adolescent rats. Orchiectomized rats showed significantly reduced time spent in the illuminated box after 30 min (test 1) or 24 h (test 2) of electrical foot-shock (training) and reduced AR-immunoreactivity in amygdala/hippocampal cornu Ammonis (CA1) in comparison to those in sham-operated rats. Treatment of orchiectomized rats with either non-aromatizable dihydrotestosterone or aromatizable testosterone were successfully reinstated these effects. Application of flutamide (AR-antagonist) in intact adolescent rats exhibited identical changes to those in orchiectomized rats. These suggest that androgens enhance the inhibitory avoidance memory plausibly by binding with AR in the amygdala and hippocampus.

scholarly journals Effects of Laser Acupuncture on Longitudinal Bone Growth in Adolescent Rats

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Mijung Yeom ◽  
Sung-Hun Kim ◽  
Bina Lee ◽  
Xiuyu Zhang ◽  
Hyangsook Lee ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Plate ◽  
Bone Growth ◽  
Growth Potential ◽  
Male Rats ◽  
Adolescent Male ◽  
Laser Acupuncture ◽  
Longitudinal Bone Growth ◽  
Level Laser ◽  
Adolescent Rats

Longitudinal bone growth is the results of chondrocyte proliferation and hypertrophy and subsequent endochondral ossification in the growth plate. Recently, laser acupuncture (LA), an intervention to stimulate acupoint with low-level laser irradiation, has been suggested as an intervention to improve the longitudinal bone growth. This study investigated the effects of laser acupuncture on growth, particularly longitudinal bone growth in adolescent male rats. Laser acupuncture was performed once every other day for a total of 9 treatments over 18 days to adolescent male rats. Morphometry of the growth plate, longitudinal bone growth rate, and the protein expression of BMP-2 and IGF-1 in growth plate were observed. The bone growth rate and the heights of growth plates were significantly increased by laser acupuncture. BMP-2 but not IGF-1 immunostaining in growth plate was increased as well. In conclusion, LA promotes longitudinal bone growth in adolescent rats, suggesting that laser acupuncture may be a promising intervention for improving the growth potential for children and adolescents.

scholarly journals Anhedonic Type Behavior and Anxiety Profile of Wistar-UIS Rats Subjected to Chronic Social Isolation

2021 ◽  
Vol 15 ◽  
Author(s):  
María Camila Acero-Castillo ◽  
María Camila Ardila-Figueroa ◽  
Silvia Botelho de Oliveira
Keyword(s):  
Social Isolation ◽  
Wistar Rats ◽  
Physiological Stress ◽  
Sucrose Solution ◽  
Preference Test ◽  
Male Rats ◽  
Adolescent Male ◽  
Physiological Stress Response ◽  
Male Wistar Rats ◽  
Anxious Behavior

Chronic Social Isolation (CSI) is a model of prolonged stress employed in a variety of studies to induce depression and anxious behavior in rats. The present study aims to evaluate the effect of CSI on male Wistar rats in terms of “anhedonic-type” behavior in the Sucrose Preference Test (SPT) and anxiogenic profile in the elevated-plus-maze (EPM) test, as well as evaluating the effect of resocialization upon sucrose consumption. A total of 24 adolescent male Wistar rats were evaluated. The animals were housed either together (communally) or socially isolated for 21 days, and then exposed for four consecutive days to the SPT test [water vs. a 32% sucrose solution (SS)]. Four days later, they were again subjected to the SPT test (32% vs. 0.7% SS), and then tested on the EPM apparatus 3 days later. Following the completion of the anxiogenic profile of the model, the animals were resocialized for 72 h and then re-tested once again using the SPT (32% vs. 0.7% SS). Twenty-four hours after this final consumption, the animals were euthanized to record the weight of their adrenal glands (AG). It was found that exposure to CSI produces anhedonic-type behavior and an anxiogenic profile in adolescent male rats, as evidenced in both the SPT and EPM tests, as well as in the animals’ physiological stress response. It was also demonstrated that resocialization does not reverse the anhedonic-type behavior, nor the physiological response to stress.

Potentiation of bromotrichloromethane hepatotoxicity in male rats exposed to 10 ppm dietary chlordecone: Electron Microscopic and biochemical study

1990 ◽  
Vol 48 (3) ◽  
pp. 284-285
Author(s):  
O. M. Faroon ◽  
R. W. Henry ◽  
M. G. Soni ◽  
H. M. Mehendale
Keyword(s):  
Free Radical ◽  
Biochemical Study ◽  
Prior Exposure ◽  
Male Rats ◽  
Cellular Injury ◽  
Low Doses ◽  
Mixed Function Oxidase ◽  
Electron Microscopic ◽  
Potent Inducer ◽  
Cellular Energy

Previous work has shown that mirex undergoes photolytic dechlorination to chlordecone (CD) (KeponeR) in the environment. Much work has shown that prior exposure to nontoxic levels of CD causes potentiation of hepatotoxicity and lethality of CCl4, BrCCl3 and other halomethane compounds. Potentiation of bromotrichloromethane hepatotoxicity has been associated with compounds that stimulate the activity of hepatic mixed-function oxidase (MFO). An increase in the metabolism of halomethane by the MFO to a free radical initiates peroxidative decomposition of membranal lipids ending in massive cellular injury. However, not all MFO inducers potentiate BrCCl3 hepatotoxicity. Potentiation by much larger doses of phenobarbital is minimal and th at by a more potent inducer of MFO, mirex, is negligible at low doses. We suggest that the CD and bromotrichloromethane interaction results in a depletion of cellular energy and thereby reducing the cellular ability to undergo mitosis.

scholarly journals The Effect of Maternal Immune Activation on Social Play-Induced Ultrasonic Vocalization in Rats

2021 ◽  
Vol 11 (3) ◽  
pp. 344
Author(s):  
Kinga Gzielo ◽  
Agnieszka Potasiewicz ◽  
Ewa Litwa ◽  
Diana Piotrowska ◽  
Piotr Popik ◽  
...  
Keyword(s):  
Immune Activation ◽  
Social Play ◽  
Autism Spectrum ◽  
Repetitive Behaviors ◽  
Male Rats ◽  
Poly I:C ◽  
Maternal Immune Activation ◽  
Increased Risk ◽  
Adolescent Rats ◽  
The Impact

Prenatal maternal infection is associated with an increased risk of various neurodevelopmental disorders, including autism spectrum disorders (ASD). Maternal immune activation (MIA) can be experimentally induced by prenatal administration of polyinosinic:polycytidylic acid (poly I:C), a synthetic viral-like double-stranded RNA. Although this MIA model is adopted in many studies, social and communicative deficits, included in the first diagnostic criterion of ASD, are poorly described in the offspring of poly(I:C)-exposed dams. This study aimed to characterize the impact of prenatal poly(I:C) exposure on socio-communicative behaviors in adolescent rats. For this purpose, social play behavior was assessed in both males and females. We also analyzed quantitative and structural changes in ultrasonic vocalizations (USVs) emitted by rats during the play test. Deficits of social play behaviors were evident only in male rats. Males also emitted a significantly decreased number of USVs during social encounters. Prenatal poly(I:C) exposure also affected acoustic call parameters, as reflected by the increased peak frequencies. Additionally, repetitive behaviors were demonstrated in autistic-like animals regardless of sex. This study demonstrates that prenatal poly(I:C) exposure impairs socio-communicative functioning in adolescent rats. USVs may be a useful tool for identifying early autistic-like abnormalities.

scholarly journals Adolescent male rats exposed to social defeat exhibit altered anxiety behavior and limbic monoamines as adults.

2009 ◽  
Vol 123 (3) ◽  
pp. 564-576 ◽  
Author(s):  
Michael J. Watt ◽  
Andrew R. Burke ◽  
Kenneth J. Renner ◽  
Gina L. Forster
Keyword(s):  
Social Defeat ◽  
Male Rats ◽  
Adolescent Male ◽  
Anxiety Behavior

Toxicological evaluation of hydroethanol leaf extract of Pupalia lappacea (Linn.) Juss. (Amaranthaceae) in rodents

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Murtala Akanji Abdullahi ◽  
Elijah Oladapo Oyinloye ◽  
Akinyinka Alabi ◽  
Aderonke Adeyinka Aderinola ◽  
Luqman Opeyemi Ogunjimi ◽  
...  
Keyword(s):  
Leaf Extract ◽  
Density Lipoprotein ◽  
Serum Testosterone ◽  
Female Rats ◽  
Male Rats ◽  
Laboratory Animals ◽  
Serum Testosterone Level ◽  
Control Group ◽  
Toxicological Evaluation ◽  
Liver And Kidney

Abstract Objectives Several studies have established the ethnobotanical benefits of Pupalia lappacea (PL) in laboratory animals without extensive toxicological evaluation of its safety profiles. Thus, an extensive toxicological investigation of sub-chronic oral administration of the hydroethanol leaf extract of P. lappacea in rodents was carried out in this study. Methods Different groups of rats were treated orally with the extract (10, 50 and 250 mg/kg) daily for 90 consecutive days. The control group received distilled water (10 mL/kg). After 90 days, some rats were left for additional 30 days without treatment for reversibility study. Blood and organs samples were collected for different evaluations at the end of study periods. Results The extract decreased the bodyweights, feeding and water intakes in female rats. PL increased the weights of the liver and kidney in male rats. PL increased the red blood cell (RBC), packed cell volume (PCV), hemoglobin (Hb), triglycerides (TRIG), cholesterol and high density lipoprotein (HDL) contents in rats. PL (250 mg/kg) significantly reduced the sperm motility and serum testosterone level. Cyto-architectural distortions of the testes, liver and spleen were visible. Conclusions The findings showed that P. lappacea is relatively safe at lower doses but cautions should be taken at higher dose.

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