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1.
bioRxiv ; 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38712190

RESUMO

Anorexia nervosa (AN) is an eating disorder observed primarily in girls and women, and is characterized by a low body mass index, hypophagia, and hyperactivity. The activity-based anorexia (ABA) paradigm models aspects of AN, and refers to the progressive weight loss, hypophagia, and hyperactivity developed by rodents exposed to time-restricted feeding and running wheel access. Recent studies identified white adipose tissue (WAT) as a primary location of the 'metabolic memory' of prior obesity, and implicated WAT-derived signals as drivers of recidivism to obesity following weight loss. Here, we tested whether an obese WAT transplant could attenuate ABA-induced weight loss in normal female mice. Recipient mice received a WAT transplant harvested from normal chow-fed, or HFD-fed obese mice; obese fat recipient (OFR) and control fat recipient (CFR) mice were then tested for ABA. During ABA, OFR mice survived longer than CFR mice, defined as maintaining 75% of their initial body weight. Next, we tested whether agouti-related peptide (AgRP) neurons, which regulate feeding behavior and metabolic sensing, mediate this effect of obese WAT transplant. CFR and OFR mice received either control or neonatal AgRP ablation, and were assessed for ABA. OFR intact mice maintained higher body weights longer than CFR intact mice, and this effect was abolished by neonatal AgRP ablation; further, ablation reduced survival in OFR, but not CFR mice. In summary, obese WAT transplant communicates with AgRP neurons to increase body weight maintenance during ABA. These findings encourage the examination of obese WAT-derived factors as potential treatments for AN.

2.
Drug Alcohol Depend ; 251: 110921, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37604013

RESUMO

Caffeinated alcoholic beverages (CABs) are widely consumed despite little known about their behavioral and biological effects. Furthermore, CABs are also popular among adolescents, a particularly vulnerable and maturing demographic. In this preliminary study, we compared levels of daily adolescent voluntary consumption of caffeine (0.03%), alcohol (10%), caffeinated alcohol (0.03% + 10%), or vehicle and evaluated the effects of this on mRNA expression in brain regions associated with addiction and known to be affected by each drug. Beginning on postnatal day 30, rats were allowed unrestricted access to gelatin combined with one, both, or neither drug for twenty days. Compared to vehicle-consuming animals, consumption of gelatin was significantly attenuated when alcohol was included. The addition of caffeine to alcohol increased alcohol consumption in the early days of access compared to alcohol alone; however, after two weeks, alcohol consumption between these groups reached comparable levels. Compared to animals consuming caffeine alone, combining caffeine with alcohol significantly reduced caffeine intake. Targeted mRNA analysis of tissue collected from the nucleus accumbens and orbitofrontal cortex after the consumption period identified unique patterns of differentially expressed genes between treatment groups, across a broad array of neurotransmitter systems. Of particular note were genes related to a number of solute transporters and serotonergic functions. This preliminary work suggests unique pharmacological and behavioral effects from consuming caffeinated alcohol during adolescence. Since CABs are widely consumed by adolescents, these results suggest that more research into the pharmacological and behavioral effects elicited by CABs is warranted.

3.
J Homosex ; : 1-26, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37405701

RESUMO

Research finds that sexual minority university students experience considerable psychological and emotional distress. Furthermore, a recent study at Brigham Young University (BYU)-a university affiliated with The Church of Jesus Christ of Latter-day Saints-found that suicidality prevalence and severity were twice as high among sexual minority students compared to their heterosexual peers. To better understand this finding, we interviewed ten sexual minority students at BYU who reported clinically significant current or previous suicidality. A coding team and auditors then analyzed and categorized the transcripts of these interviews using the Consensual Qualitative Research methodology. Five domains emerged related to suicidality among sexual minority students: deterrents from suicidal ideation and intent; contributors to suicidal ideation and intent; religious and spiritual experiences; experiences with BYU; and suggested improvements. We found patterns consistent with previous literature, including relational and belonging factors contributing to suicidality; we also found that certain doctrinal interpretations were related to increased suicidality. The primary improvement requested by participants was feeling better understood and accepted (rather than ignored or marginalized). We discuss study limitations (including small sample size and low generalizability,), future directions for research, and implications for religious university campuses.

5.
Behav Brain Res ; 440: 114262, 2023 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-36529299

RESUMO

Psilocybin and its active metabolite psilocin are hallucinogenic serotonergic agonists with high affinity for several serotonin receptors. In addition to underlying the hallucinogenic effects of these compounds, serotonin receptor activation also has important effects on decision-making and goal-directed behaviors. The impact of psilocybin and psilocin on these cognitive systems, however, remains unclear. This study investigated the effects of psilocybin treatment on decision-making and motivation in healthy male and female rats. We compared probability and delay discounting performance of psilocybin treated (1 mg/kg) to vehicle rats (n = 10/sex/group), and further assessed motivation in each group using a progressive ratio task. We also confirmed drug action by assessing head twitch responses after psilocybin treatment (1 mg/kg). Results from this study demonstrated that exposure to 1 mg/kg psilocybin did not affect decision-making in the probability and delay discounting tasks and did not reduce response rates in the progressive ratio task. However, psilocybin treatment did cause the expected increase in head twitch responses in both male and female rats, demonstrating that the drug was delivered at a pharmacologically relevant dosage. Combined, these results suggest that psilocybin may not impair or improve decision-making and motivation. Considering recent interest in psilocybin as a potential fast-acting therapeutic for a variety of mental health disorders, our findings also suggest the therapeutic effects of this drug may not be mediated by changes to the brain systems underlying reward and decision-making. Finally, these results may have important implications regarding the relative safety of this compound, suggesting that widespread cognitive impairments may not be seen in subjects, even after chronic treatment.


Assuntos
Alucinógenos , Psilocibina , Ratos , Masculino , Feminino , Animais , Psilocibina/farmacologia , Alucinógenos/farmacologia , Motivação , Encéfalo/metabolismo , Serotonina/farmacologia , Receptores de Serotonina/metabolismo
6.
Psychol Res ; 87(2): 519-536, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35249147

RESUMO

The rubber hand illusion (RHI) is a perceptual illusion in which one is made to feel that a hand-shaped object is part of their body. This illusion is believed to be the result of the integration of afferent information. However, there has been an increasing amount of evidence that suggests efferent information plays a role in this illusion as well. Previous research has found that individuals who are afflicted by pathological lack of movement experience the RHI more vividly than control participants. Whereas individuals who move their hands more than the general population (i.e. professional pianists) experience the RHI less vividly than control participants. Based upon the available evidence it would seem that muscle activity prior to experiencing the RHI should be associated with how vividly one experiences different indices of the illusion. In the present study we tested this possibility by having participants perform a maximum voluntary muscle contraction task prior to experiencing three variants of the RHI (moving active, moving passive and classic). It was found that electromyographic features known to be indicative of muscle fatigue exhibited a positive association with proprioceptive drift when stimulation was synchronous or visual movement only (with the exception of the passive moving RHI synchronous condition). More work is needed to better characterize the muscular processes associated with experiencing the RHI.


Assuntos
Ilusões , Percepção do Tato , Humanos , Ilusões/fisiologia , Percepção Visual/fisiologia , Imagem Corporal , Mãos/fisiologia , Propriocepção/fisiologia , Músculos , Percepção do Tato/fisiologia
7.
Metab Eng Commun ; 14: e00196, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35310468

RESUMO

Interest in the potential therapeutic efficacy of psilocybin and other psychedelic compounds has escalated significantly in recent years. To date, little is known regarding the biological activity of the psilocybin pathway intermediate, norbaeocystin, due to limitations around sourcing the phosphorylated tryptamine metabolite for in vivo testing. To address this limitation, we first developed a novel E. coli platform for the rapid and scalable production of gram-scale amounts of norbaeocystin. Through this process we compare the genetic and fermentation optimization strategies to that of a similarly constructed and previously reported psilocybin producing strain, uncovering the need for reoptimization and balancing upon even minor genetic modifications to the production host. We then perform in vivo measurements of head twitch response to both biosynthesized psilocybin and norbaeocystin using both a cell broth and water vehicle in Long-Evans rats. The data show a dose response to psilocybin while norbaeocystin does not elicit any pharmacological response, suggesting that norbaeocystin and its metabolites may not have a strong affinity for the serotonin 2A receptor. The findings presented here provide a mechanism to source norbaeocystin for future studies to evaluate its disease efficacy in animal models, both individually and in combination with psilocybin, and support the safety of cell broth as a drug delivery vehicle.

8.
Mol Psychiatry ; 26(8): 3765-3777, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-31863019

RESUMO

Anorexia nervosa (AN) is an eating disorder observed predominantly in women and girls that is characterized by a low body-mass index, hypophagia, and hyperactivity. Activity-based anorexia (ABA), which refers to the weight loss, hypophagia, and hyperactivity exhibited by rodents exposed to both running wheels and scheduled fasting, provides a model for aspects of AN. Increased dopamine D2/D3 receptor binding in the anteroventral striatum has been reported in AN patients. We virally overexpressed D2Rs on nucleus accumbens core (D2R-OENAc) neurons that endogenously express D2Rs, and tested mice of both sexes in the open field test, ABA paradigm, and intraperitoneal glucose tolerance test (IGTT). D2R-OENAc did not alter baseline body weight, but increased locomotor activity in the open field across both sexes. During constant access to food and running wheels, D2R-OENAc mice of both sexes increased food intake and ran more than controls. However, when food was available only 7 h a day, only female D2R-OENAc mice rapidly lost 25% of their initial body weight, reduced food intake, and substantially increased wheel running. Surprisingly, female D2R-OENAc mice also rapidly lost 25% of their initial body weight during scheduled fasting without wheel access and showed no changes in food intake. In contrast, male D2R-OENAc mice maintained body weight during scheduled fasting. D2R-OENAc mice of both sexes also showed glucose intolerance in the IGTT. In conclusion, D2R-OENAc alters glucose metabolism in both sexes but drives robust weight loss only in females during scheduled fasting, implicating metabolic mechanisms in this sexually dimorphic effect.


Assuntos
Atividade Motora , Núcleo Accumbens , Receptores de Dopamina D2 , Redução de Peso , Animais , Jejum , Feminino , Masculino , Camundongos , Núcleo Accumbens/metabolismo , Receptores de Dopamina D2/genética , Receptores de Dopamina D2/metabolismo
9.
Horm Behav ; 125: 104840, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32795469

RESUMO

The hormone oxytocin has long been associated with social behaviors, but recent evidence suggests that it may also affect reward processing in non-social contexts. Decisions are an integral component of many social and reward-based behavioral paradigms. Thus, a broad role for oxytocin in decision-making may explain the wide variety of effects that have been previously observed and resolve controversies in the literature about its role. To determine if oxytocin can selectively modulate decision-making in male rats, we assessed the dose-dependent effects of central (intracerebroventricular) or peripheral (intraperitoneal) administration of oxytocin on probability and delay discounting, two commonly used decision-making tasks that are free of social contexts. Our results showed that central administration of oxytocin dose-dependently reduced preference for risky outcomes in the probability discounting task, but had no impact on delay discounting or reward sensitivity. This effect was blocked by the co-administration of an oxytocin antagonist. Additionally, we found no effect of peripheral oxytocin administration on any task. To identify potential cognitive mechanisms of central oxytocin's effect on decision-making, we determined if central or peripheral oxytocin affects reward sensitivity using an intracranial self-stimulation task, and motivation using a progressive ratio task. These results showed that at the dosage that affects decision-making, central oxytocin had a mild and short-lasting effect on motivation, but no observable effect on reward sensitivity. This pattern of results suggests that oxytocin may selectively reduce risky decisions in male rats, even at dosages that have no major effects on reward processing and motivation. These findings highlight a potentially novel role for oxytocin in non-social cognitive processes and expand our understanding of the mechanism by which oxytocin may regulate social behavior.


Assuntos
Comportamento Animal/efeitos dos fármacos , Tomada de Decisões/efeitos dos fármacos , Ocitocina/administração & dosagem , Assunção de Riscos , Animais , Tomada de Decisões/fisiologia , Desvalorização pelo Atraso/efeitos dos fármacos , Comportamento Impulsivo/efeitos dos fármacos , Masculino , Motivação/efeitos dos fármacos , Ocitocina/antagonistas & inibidores , Ocitocina/farmacologia , Ratos , Ratos Sprague-Dawley , Recompensa , Comportamento Social
10.
J Exp Anal Behav ; 114(2): 179-192, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32776567

RESUMO

Rodent studies on decision-making often use food rewards and food-restrict subjects in order to motivate performance. However, food restriction has widespread effects on brain and behavior, which depend on factors including extent of restriction and feeding schedule. These factors are well recognized for their effects on motivation, but may also cause effects on decision-making independent of motivation. We examined how the degree of weight-based food restriction in rats influenced decision-making on the probability and delay discounting tasks. Additionally, we examined how the method of food restriction (consistent amount vs. time constrained feeding schedule) influenced decision-making. Our results showed that the degree of weight-based food restriction significantly altered probability, but not delay discounting, and that these effects were not entirely explainable by differences in motivation. Additionally, the method of food restriction did not significantly influence discounting when animals were within the same range of weight-based restriction. Together, our findings suggest that the degree of food restriction may modulate the neural circuitry responsible for selective aspects of decision-making related to probability. Further, these data support the need for tight control and reporting of weight and feeding in studies relying on food restriction, and suggest that the effects of food restriction may be broader than previously considered.


Assuntos
Desvalorização pelo Atraso , Recompensa , Animais , Encéfalo , Alimentos , Motivação , Probabilidade , Ratos
11.
J Undergrad Neurosci Educ ; 19(1): A52-A63, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33880092

RESUMO

Undergraduate research experiences have emerged as some of the most beneficial high-impact practices in education, providing clear benefits to students that include improved critical thinking and scientific reasoning, increased academic performance, and enhanced retention both within STEM majors and in college overall. These benefits extend to faculty members as well. Several disciplines, including neuroscience, have implemented research as part of their curriculum, yet many research opportunities target late stage undergraduates, despite evidence that early engagement can maximize the beneficial nature of such work. A 2019 Society for Neuroscience professional development workshop provided multiple examples of integrating research into an undergraduate curriculum, including early engagement (Fernandes, 2020). This article is the first in a series of three that expands upon the information presented in those workshop discussions, focusing on ways to promote early research opportunities. The benefits and challenges associated with early research engagement suggest thoughtful consideration of the best mechanisms for implementation are warranted; some options might include apprenticeship models or course-based approaches. Regardless of mechanism, early research can serve to initiate more prolonged, progressive, scaffolded experiences that span the academic undergraduate career.

12.
J Undergrad Neurosci Educ ; 19(1): A64-A74, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33880093

RESUMO

Undergraduate research experiences are widely regarded as high-impact practices that foster meaningful mentoring relationships, enhance retention and graduation, and stimulate postbaccalaureate enrollment in STEM graduate and professional programs. Through immersion in a mentored original research project, student develop and apply their skills in critical thinking, problem solving, intellectual independence, communication, collaboration, project ownership, innovation, and leadership. These skills are readily transferable to a wide array of future careers in and beyond STEM that are well-served by evidence-based approaches. The 2019 Society for Neuroscience meeting included a well-attended workshop on integrating research into the curriculum at primarily undergraduate institutions (PUIs). This article is the second of three articles that summarize, analyze, and expand the workshop discussions. In this second article, we specifically describe approaches to transitional research courses that prepare students for independent research experiences such as undergraduate research theses. Educators can intentionally scaffold research experience and skills across the curriculum, to foster participation in scientific research and enhance diversity, equity, and inclusivity in research training. This article provides an overview of important goals and considerations for intermediate undergraduate research experiences, specific examples from several institutions of transitional courses that scaffold research preparation using different structures, and a summary of lessons learned from these experiences.

13.
J Undergrad Neurosci Educ ; 19(1): A75-A88, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33880094

RESUMO

The benefits of undergraduate training in research are significant. Integration of such training into the undergraduate experience, however, can be challenging at institutions without extensive research programs, and may inadvertently exclude some populations of students. Therefore, inclusion of research into the academic curriculum ensures all students can access this important training. The 2019 annual meeting of the Society for Neuroscience included a workshop on integrating research into the curriculum at primarily undergraduate institutions (PUIs). In this last article of a three-part series, we describe models for integrating research into advanced stages of the undergraduate curriculum, specifically for juniors and seniors. First, we describe multiple models of faculty-mentored group-based research. Second, we detail a peer-mentored research system, in which seniors mentor groups of first through third year students. Third, we describe multiple examples of integrating research into "capstone" courses for seniors. Fourth, we describe models in which a senior thesis is a graduation requirement for all students. Lastly, we describe several models of implementing an optional honors thesis for students. Although similarities exist across these programs, their differences allow for specific secondary objectives to be met, which are often unique to institutions and/or departments. Therefore, for each of these examples, we describe the context, specific design, and required student assessments. We conclude by discussing some of the key successes and challenges of developing programs that facilitate undergraduate research by upper-level students, and suggest a number of concepts that should be considered by individuals developing and assessing new programs.

14.
Behav Brain Res ; 380: 112449, 2020 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-31870780

RESUMO

Alcohol use disorder is pervasive and effects the health of millions. Identifying factors such as early life stress that contribute to the development of alcohol use disorder is therefore critical, especially those that contribute to adolescent drinking, a strong predictor of AUD development. The majority of prior studies have examined early life effects on adult drinking, but have not studied intake during adolescence, and no prior studies have examined how the effects of multiple stressors may be additive. Therefore, this study determined if experiencing individual or multiple stressors increases adolescent alcohol intake. Male Long Evans rats underwent either early or late maternal separation (postnatal day 2-9 or 13-20), early adolescent social defeat (PND 30-40), both, or neither. All rats were then given two-hour access to alcohol, and voluntary intake assessed daily in late adolescence (PND 41-51). In adulthood, sensitivity to alcohol's sedative effects was assessed using loss and regain of righting reflex tests. Results indicate that experiencing maternal separation (at either time point) or social defeat increased adolescent alcohol consumption, but experiencing the combined stressors did not, and that no stressor significantly affected body weight during adolescence or loss and regain of righting reflex in adulthood. Overall, this pattern of effects suggests that experiencing any individual early life stressor may increase adolescent alcohol intake, in agreement with prior literature, but that the combined effects of multiple early life stressors may be more complicated.


Assuntos
Consumo de Bebidas Alcoólicas/fisiopatologia , Alcoolismo/etiologia , Comportamento Animal/fisiologia , Privação Materna , Derrota Social , Estresse Psicológico/complicações , Fatores Etários , Animais , Modelos Animais de Doenças , Masculino , Ratos , Ratos Long-Evans
15.
Am Surg ; 84(3): 351-357, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29559048

RESUMO

The role of MRI in the workup of newly diagnosed breast cancer patients remains controversial. Breast MRI detects additional disease, but this has not translated into improved outcomes. In light of a dramatic rise in MRI use, we investigated patterns of MRI ordering for newly diagnosed breast cancer. All newly diagnosed breast cancer cases presenting for surgical management to a specialized breast center from 2011 to 2013 were reviewed. Patients who had an MRI ordered by their operating surgeon were compared with those who had an MRI completed previously. Of 1037 patients, 504 (49%) with newly diagnosed breast cancer underwent MRI as part of their preoperative evaluation. Variables associated with MRI use included commercial insurance, increased breast density, genetic testing, mamographically occult disease, and lobular pathology. Of women who presented to our center with an MRI already completed, 63 per cent were ordered by a primary care provider. Of the 504 patients, 233 (44%) who had an MRI underwent an additional biopsy, and 166 (33%) had a resultant change in management. There was no significant difference in MRI-directed change in patient care depending on ordering provider. Further research is needed to develop evidence-based guidelines for preoperative MRI evaluation to optimize patient outcomes.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Imageamento por Ressonância Magnética/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Período Pré-Operatório , Atenção Primária à Saúde/estatística & dados numéricos
16.
eNeuro ; 4(2)2017.
Artigo em Inglês | MEDLINE | ID: mdl-28466068

RESUMO

Animal models of decision-making rely on an animal's motivation to decide and its ability to detect differences among various alternatives. Food reinforcement, although commonly used, is associated with problematic confounds, especially satiety. Here, we examined the use of brain stimulation reward (BSR) as an alternative reinforcer in rodent models of decision-making and compared it with the effectiveness of sugar pellets. The discriminability of various BSR frequencies was compared to differing numbers of sugar pellets in separate free-choice tasks. We found that BSR was more discriminable and motivated greater task engagement and more consistent preference for the larger reward. We then investigated whether rats prefer BSR of varying frequencies over sugar pellets. We found that animals showed either a clear preference for sugar reward or no preference between reward modalities, depending on the frequency of the BSR alternative and the size of the sugar reward. Overall, these results suggest that BSR is an effective reinforcer in rodent decision-making tasks, removing food-related confounds and resulting in more accurate, consistent, and reliable metrics of choice.


Assuntos
Encéfalo/fisiologia , Comportamento de Escolha/fisiologia , Tomada de Decisões/fisiologia , Reforço Psicológico , Recompensa , Animais , Comportamento Animal/fisiologia , Condicionamento Operante/fisiologia , Estimulação Elétrica , Alimentos , Masculino , Motivação/fisiologia , Ratos Long-Evans
17.
J Surg Res ; 210: 177-180, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28457325

RESUMO

BACKGROUND: Nonpalpable breast lesions require localization before excision. This is most commonly performed with a wire (WL) or a radioactive seed (SL), which is placed into the breast under radiographic guidance. Although there are advantages of each modality, there are no guidelines to address which patients should undergo WL versus SL. We investigated factors influencing the selection of SL versus WL at our institution and assessed patient satisfaction with each procedure. METHODS: Patients undergoing preoperative localization of nonpalpable breast lesions from May 2014 through August 2015 were included. Physicians were surveyed on surgical scheduling to evaluate factors influencing the decision to perform SL or WL. Patient satisfaction was evaluated with a survey at the first postoperative visit. Retrospective chart review was performed. RESULTS: 341 patients were included: 104 (30%) patients underwent SL and 237 (70%) underwent WL. There was no difference in patient age, benign versus malignant disease, or need for concomitant axillary surgery comparing the SL versus WL groups. Physician survey indicated that 18% of patients were candidates for WL only. Of the patients who were eligible for both, 88 (41%) ultimately underwent SL and 126 (59%) had WL. The most commonly cited reason for selection of one localization method or the other was physician preference, followed by patient preference or avoiding additional visit. There was no significant difference in self-reported preoperative anxiety level, convenience of the localization procedure, pain of the localization procedure, operative experience, postoperative pain level or medication requirement, or overall patient satisfaction comparing patients who underwent SL and WL. CONCLUSIONS: SL and WL offer patients similar comfort and satisfaction. Factors influencing selection of one modality over the other include both logistic and clinical considerations.


Assuntos
Atitude do Pessoal de Saúde , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/cirurgia , Marcadores Fiduciais , Satisfação do Paciente/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Compostos Radiofarmacêuticos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Pessoa de Meia-Idade , New York , Estudos Retrospectivos
18.
Behav Brain Res ; 324: 100-108, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28212944

RESUMO

Though commonly used as a treatment for ADHD, the psychostimulant methylphenidate (MPH) is also misused and abused in adolescence in both clinical and general populations. Although MPH acts via pathways activated by other drugs of abuse, the short- and long-term effects of MPH on reward processing in learning and decision-making are not clearly understood. We examined the effect of adolescent MPH treatment on a battery of reward-directed behaviors both in adolescence during its administration and in adulthood after its discontinuation. We further measured whether MPH had lasting effects on dopamine receptor mRNA expression in orbitofrontal cortex (OFC) that may correspond with behavior. Long-Evans rats were injected with MPH (0, 1, 2.5, or 5mg/kg IP) twice daily from middle to late adolescence (PD38-57). During adolescence, the high dose of MPH reduced preference for large rewards in a Reward Magnitude Discrimination task, but did not affect preference for smaller-sooner rewards in a Delay Discounting task. In adulthood, after discontinuation of MPH, animals previously treated with the moderate dose of MPH showed improved acquisition, but not reversal, in a Reversal Learning task. MPH exposure did not increase preference for large-risky rewards in a Risk task in adulthood. We then quantified mRNA expression of D1, D2, and D3 receptors in the OFC using qPCR. MPH increased mRNA expression of dopamine D3 receptor subtype, but not D1 or D2. Overall, these results indicate that MPH has both immediate and lasting effects on reward-dependent learning and decisions, as well as dopaminergic function in rodents.


Assuntos
Tomada de Decisões/efeitos dos fármacos , Metilfenidato/administração & dosagem , Córtex Pré-Frontal/efeitos dos fármacos , Receptores Dopaminérgicos/metabolismo , Recompensa , Animais , Desvalorização pelo Atraso/efeitos dos fármacos , Inibidores da Captação de Dopamina/administração & dosagem , Masculino , Córtex Pré-Frontal/metabolismo , RNA Mensageiro/metabolismo , Ratos Long-Evans , Reversão de Aprendizagem/efeitos dos fármacos
19.
Soc Neurosci ; 12(1): 50-64, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27295326

RESUMO

Maternal presence has a potent buffering effect on infant fear and stress responses in primates. We previously reported that maternal presence is not effective in buffering the endocrine stress response in infant rhesus monkeys reared by maltreating mothers. We have also reported that maltreating mothers show low maternal responsiveness and permissiveness/secure-base behavior. Although still not understood, it is possible that this maternal buffering effect is mediated, at least partially, through deactivation of amygdala response circuits when mothers are present. Here, we studied rhesus monkey infants that differed in the quality of early maternal care to investigate how this early experience modulated maternal buffering effects on behavioral responses to novelty during the weaning period. We also examined the relationship between these behavioral responses and structural connectivity in one of the underlying regulatory neural circuits: amygdala-prefrontal pathways. Our findings suggest that infant exploration in a novel situation is predicted by maternal responsiveness and structural integrity of amygdala-prefrontal white matter depending on maternal presence (positive relationships when mother is absent). These results provide evidence that maternal buffering of infant behavioral inhibition is dependent on the quality of maternal care and structural connectivity of neural pathways that are sensitive to early life stress.


Assuntos
Tonsila do Cerebelo/diagnóstico por imagem , Tonsila do Cerebelo/crescimento & desenvolvimento , Comportamento Materno/psicologia , Córtex Pré-Frontal/diagnóstico por imagem , Córtex Pré-Frontal/crescimento & desenvolvimento , Estresse Psicológico/diagnóstico por imagem , Análise de Variância , Animais , Maus-Tratos Infantis/psicologia , Imagem de Difusão por Ressonância Magnética , Imagem de Tensor de Difusão , Modelos Animais de Doenças , Feminino , Humanos , Lactente , Macaca mulatta , Masculino , Mães , Atividade Motora , Testes Psicológicos , Distribuição Aleatória
20.
PLoS One ; 11(11): e0166756, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27861553

RESUMO

Anorexia nervosa (AN) is a complex eating disorder with severe dysregulation of appetitive behavior. The activity-based anorexia (ABA) paradigm is an animal model in which rodents exposed to both running wheels and scheduled feeding develop aspects of AN including paradoxical hypophagia, dramatic weight loss, and hyperactivity, while animals exposed to only one condition maintain normal body weight. Brain-derived neurotrophic factor (BDNF), an activity-dependent modulator of neuronal plasticity, is reduced in the serum of AN patients, and is a known regulator of feeding and weight maintenance. We assessed the effects of scheduled feeding, running wheel access, or both on the expression of BDNF transcripts within the mesocorticolimbic pathway. We also assessed the expression of neuronal cell adhesion molecule 1 (NCAM1) to explore the specificity of effects on BDNF within the mesocorticolimbic pathway. Scheduled feeding increased the levels of both transcripts in the hippocampus (HPC), increased NCAM1 mRNA expression in the ventral tegmental area (VTA), and decreased BDNF mRNA levels in the medial prefrontal cortex (mPFC). In addition, wheel running increased BDNF mRNA expression in the VTA. No changes in either transcript were observed in the nucleus accumbens (NAc). Furthermore, no changes in either transcript were induced by the combined scheduled feeding and wheel access condition. These data indicate that scheduled feeding or wheel running alter BDNF and NCAM1 expression levels in specific regions of the mesocorticolimbic pathway. These findings contribute to our current knowledge of the molecular alterations induced by ABA and may help elucidate possible mechanisms of AN pathology.


Assuntos
Anorexia/etiologia , Anorexia/fisiopatologia , Fator Neurotrófico Derivado do Encéfalo/genética , Expressão Gênica , Atividade Motora , Recompensa , Animais , Comportamento Animal , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Camundongos , Esforço Físico
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