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1.
Artículo en Inglés | MEDLINE | ID: mdl-38630316

RESUMEN

RATIONALE: Corticotropin-releasing factor (CRF), the apical stress-inducing hormone, exacerbates stress and addictive behaviors. TCAP-1 is a peptide that directly inhibits both CRF-mediated stress and addiction-related behaviors; however, the direct action of TCAP-1 on morphine withdrawal-associated behaviors has not previously been examined. OBJECTIVE: To determine whether TCAP-1 administration attenuates behavioral and physiological consequences of morphine withdrawal in mice. METHODS: Mice were administered via subcutaneous route TCAP-1 either before or after initial morphine exposure, after which jumping behavior was quantified to assess the effects of TCAP-1 on naloxone-precipitated morphine withdrawal. As a comparison, mice were treated with nonpeptide CRF1 receptor antagonist CP-154,526. In one experiment, plasma corticosterone (CORT) was also measured as a physiological stress indicator. RESULTS: Pretreatment with TCAP-1 (10-250 nmol/kg) before morphine treatment significantly inhibited the development of naloxone-precipitated withdrawal. TCAP-1 (250-500 nmol/kg) treatment administered after morphine treatment attenuated the behavioral expression of naloxone-precipitated withdrawal. TCAP-1 (250 nmol/kg) treatment during morphine treatment was more effective than the optimal dosing of CP-154,526 (20 mg/kg) at suppressing the behavioral expression of naloxone-precipitated withdrawal, despite similar reduction of withdrawal-induced plasma CORT level increases. CONCLUSIONS: These findings establish TCAP-1 as a potential therapeutic candidate for the prevention and treatment of morphine withdrawal.

2.
J Cancer Surviv ; 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38630333

RESUMEN

PURPOSE: This study aims to characterize patterns in ototoxicity monitoring and identify potential barriers to audiologic follow-up. METHODS: We performed a single-institution retrospective cohort study on adult (≥ 18 years old) cancer patients treated with cisplatin from January 2014 to September 2021. Our primary outcomes were rates of baseline and post-treatment audiograms at the following time points: 3, 6, 12, and greater than 12 months. Time-to-event analyses were performed to describe additional insights to ototoxicity monitoring patterns. RESULTS: Nine hundred fifty-five patients with cancer were included for analysis. The most common primary cancer sites were head and neck (64%), followed by cervical (24%). Three hundred seventy-three patients (39%) underwent baseline audiometric assessment, 38 patients (4%) received audiologic evaluation during chemotherapy, and 346 patients (36%) obtained at least one post-treatment audiogram. Audiologic follow-up was greatest within 3 months of completing chemotherapy (26%), but this tapered dramatically to less than 10% at every other post-treatment time point. Patients with head and neck cancer achieved higher rates of audiologic follow-up at every time point than patients with non-head and neck cancer except for during treatment. CONCLUSIONS: Ototoxicity monitoring is an inconsistent practice, particularly during chemotherapy and for long-term surveillance of hearing loss. Patients with non-head and neck cancer may be at increased risk for loss of audiologic follow-up. IMPLICATIONS FOR CANCER SURVIVORS: Cisplatin ototoxicity is a common occurrence that can be effectively managed with auditory rehabilitation. Therefore, referrals to audiology and counseling on treatment-related ototoxicity are recommended throughout chemotherapy and cancer survivorship.

3.
Gland Surg ; 13(1): 4-18, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38323236

RESUMEN

Background: Radiofrequency ablation (RFA) utilizes minimally invasive high-energy current to precisely ablate tumor cells. It has been utilized in many cancer types including thyroid, lung, and liver cancer. It has been shown to provide adequate ablative margins with minimal complications; however, incomplete RFA may lead to recurrence of tumor. The underlying cellular mechanism and behavior of ablated cancer tissue is poorly understood. Methods: A systematic review was performed, searching EMBASE, Web of Science, PubMed, and Scopus for studies published up to March 2022 and reported following PRISMA guidelines. Collection was performed by two groups of investigators to avoid risk of bias. The Cochrane Collaboration's tool was used for assessing risk of bias. We identified human, in vivo, and in vitro research studies utilizing RFA for tumor tissues. We required that the studies included at least one of the following: complications, recurrence, or survival, and took interest to studies identifying cellular signaling pathway patterns after RFA. Descriptive statistical analysis was performed in 'R' software including mean and confidence interval. Results: The most frequent cancers studied were liver and lung cancers accounting for 57.4% (N=995) and 15.4% (N=267), followed by esophageal (N=190) and breast cancer (N=134). The most common reported complications were bleeding (19%) and post-operative pain (14%). In our literature search, four independent studies showed upregulation and activation of the VEGF pathway following RFA, four showed upregulation and activation of the AKT pathway following RFA, three studies demonstrated involvement of matrix metalloproteinases, and four showed upregulation of c-Met protein following RFA. Conclusions: In our review and meta-analysis, we identify several proteins and pathways of interest of which are important in wound healing, angiogenesis, and cellular growth and survival. These proteins and pathways of interest may implicate areas of research towards RFA resistance and cancer recurrence.

4.
Gland Surg ; 12(4): 432-441, 2023 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-37200932

RESUMEN

Background: Despite extensive research on sex differences in primary thyroid cancer, there is a lack of data on the role of sex in the risk of developing second primary thyroid cancer (SPTC). We aimed to investigate the risk of SPTC development according to patient sex, with an emphasis concerning previous malignancy location as well as age. Methods: Cancer survivors diagnosed with SPTC were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The SEER*Stat software package obtained standardized incidence ratios (SIR) and absolute excess risks of subsequent thyroid cancer development. Results: Data for 9,730 (62.3%) females and 5,890 (37.7%) males were extracted for a total of 15,620 SPTC individuals. Asian/Pacific Islanders had the highest incidence of SPTC [SIR =2.67, 95% confidence interval (CI): 2.49-2.86]. The risk of SPTC was higher in males (SIR =2.01, 95% CI: 1.94-2.08) than when compared to females (SIR =1.83, 95% CI: 1.79-1.88; P<0.001). Head and neck tumors had significantly higher SIRs for SPTC development in males when compared to females. Conclusions: Survivors of primary malignancies have an increased risk SPTC, especially males. Our work suggests that oncologists and endocrinologists may consider the need for increased surveillance of both male and female patients given their increased risk of SPTC.

5.
Nat Neurosci ; 26(5): 830-839, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37081296

RESUMEN

Dopamine neuron activity is tied to the prediction error in temporal difference reinforcement learning models. These models make significant simplifying assumptions, particularly with regard to the structure of the predictions fed into the dopamine neurons, which consist of a single chain of timepoint states. Although this predictive structure can explain error signals observed in many studies, it cannot cope with settings where subjects might infer multiple independent events and outcomes. In the present study, we recorded dopamine neurons in the ventral tegmental area in such a setting to test the validity of the single-stream assumption. Rats were trained in an odor-based choice task, in which the timing and identity of one of several rewards delivered in each trial changed across trial blocks. This design revealed an error signaling pattern that requires the dopamine neurons to access and update multiple independent predictive streams reflecting the subject's belief about timing and potentially unique identities of expected rewards.


Asunto(s)
Refuerzo en Psicología , Área Tegmental Ventral , Ratas , Animales , Área Tegmental Ventral/fisiología , Aprendizaje/fisiología , Recompensa , Neuronas Dopaminérgicas/fisiología , Dopamina/fisiología
6.
Am Surg ; 89(4): 566-573, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36565153

RESUMEN

INTRODUCTION: The gender and minority gap in general surgery residency is narrowing; however, literature lacks comprehensive data regarding the demographics of fellowship programs following general surgery training. METHODS: Data from 2017 to 2021 for gender, ethnicity, and surgical subspecialty are publicly available from the ERAS database and ACGME yearly data reports. Cochran-Armitage trend tests were used to determine statistical significance in trends for female and minority applicants and trainees. RESULTS: The overall trend of female applicants to surgical specialties remained stagnant. However, female applicants to vascular surgery increased significantly from 25% to 35% (P = .045). There was no significant increase in female trainees in any surgical specialties evaluated. Furthermore, the overall trend of minority applicants to surgical specialties also remained stagnant, except for pediatric surgery, which showed significantly fewer minority applicants. Despite pediatric surgery having fewer applicants, minority trainees in this specialty increased significantly from 8% to 19% (P = .008). CONCLUSION: Several current initiatives, such as intentional mentorship, are being reported to promote diverse and equal representation among female and minority applicants and trainees. However, the current overall margin of increase in diversity among surgical specialty applicants and trainees is minimal, indicating that continued efforts are needed to diversify surgical specialty training programs.


Asunto(s)
Internado y Residencia , Especialidades Quirúrgicas , Niño , Humanos , Femenino , Estados Unidos , Becas , Educación de Postgrado en Medicina , Etnicidad
7.
PLoS One ; 17(10): e0276232, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36260622

RESUMEN

The endothelial glycocalyx (EGX) contributes to the permeability barrier of vessels and regulates the coagulation cascade. EGX damage, which occurs in numerous disease states, including sepsis and trauma, results in endotheliopathy. While influenza and other viral infections are known to cause endothelial dysfunction, their effect on the EGX has not been described. We hypothesized that the H1N1 influenza virus would cause EGX degradation. Human umbilical vein endothelial cells (HUVECs) were exposed to varying multiplicities of infection (MOI) of the H1N1 strain of influenza virus for 24 hours. A dose-dependent effect was examined by using an MOI of 5 (n = 541), 15 (n = 714), 30 (n = 596), and 60 (n = 653) and compared to a control (n = 607). Cells were fixed and stained with FITC-labelled wheat germ agglutinin to quantify EGX. There was no difference in EGX intensity after exposure to H1N1 at an MOI of 5 compared to control (6.20 vs. 6.56 Arbitrary Units (AU), p = 0.50). EGX intensity was decreased at an MOI of 15 compared to control (5.36 vs. 6.56 AU, p<0.001). The degree of EGX degradation was worse at higher doses of the H1N1 virus; however, the decrease in EGX intensity was maximized at an MOI of 30. Injury at MOI of 60 was not worse than MOI of 30. (4.17 vs. 4.47 AU, p = 0.13). The H1N1 virus induces endothelial dysfunction by causing EGX degradation in a dose-dependent fashion. Further studies are needed to characterize the role of this EGX damage in causing clinically significant lung injury during acute viral infection.


Asunto(s)
Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Enfermedades Vasculares , Humanos , Glicocálix/metabolismo , Fluoresceína-5-Isotiocianato/metabolismo , Gripe Humana/metabolismo , Células Endoteliales de la Vena Umbilical Humana , Enfermedades Vasculares/metabolismo , Aglutininas del Germen de Trigo/metabolismo
8.
Biomedicines ; 10(10)2022 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-36289838

RESUMEN

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer worldwide and is known to spread to adjacent neck lymphatics. Lymph node metastasis (LNM) is a known predictor of disease recurrence and is an indicator for aggressive resection. Our study aims to determine if ultrasound sonographers' degree of training influences overall LNM detection. PubMed, Embase, and Scopus articles were searched and screened for relevant articles. Two investigators independently screened and extracted the data. Diagnostic test parameters were determined for all studies, studies reported by radiologists, and studies reported by non-radiologists. The total sample size amounted to 5768 patients and 10,030 lymph nodes. Radiologists performed ultrasounds in 18 studies, while non-radiologists performed ultrasounds in seven studies, corresponding to 4442 and 1326 patients, respectively. The overall sensitivity of LNM detection by US was 59% (95%CI = 58-60%), and the overall specificity was 85% (95%CI = 84-86%). The sensitivity and specificity of US performed by radiologists were 58% and 86%, respectively. The sensitivity and specificity of US performed by non-radiologists were 62% and 78%, respectively. Summary receiver operating curve (sROC) found radiologists and non-radiologists to detect LNM on US with similar accuracy (p = 0.517). Our work suggests that both radiologists and non-radiologists alike detect overall LNM with high accuracy on US.

9.
Biomedicines ; 10(8)2022 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-36009531

RESUMEN

Primary cancer survivors have a higher risk of developing second primary thyroid cancer (SPTC). Patients with SPTC who survived primary malignancies, diagnosed from 1975 to 2016, were identified from the Surveillance, Epidemiology, and End Results (SEER) database (SEER 18 Registry). A total of 33,551 cancer cases were enrolled in the final analysis. Individuals with a primary malignancy were at a significant 90% increased risk of developing SPTC (SIR = 1.90, 95%CI = 1.86−1.93, p < 0.05) compared to the general population. More than half (54.7%) of SPTC diagnoses were made in the first three years after primary cancer diagnosis, and the most aggressive presentations of SPTC occurred within the first year following malignancy. A latency trend analysis identified persistent high risk for development of SPTC after diagnosis of lymphoma, leukemia, soft tissue tumors, kidney, breast, and uterine cancer; elevated 10-year risk for most cancers such as salivary gland, melanoma, stomach, lung, colon, ovarian, pancreas, prostate, and bladder; and high 5-year risk after cancers such as larynx, oral, orbit, bone, small intestine, and liver. Our latency period model identifying risk according to each type of primary cancer may aid clinicians in identifying at-risk patients to be screened for thyroid cancer and guide them in developing a surveillance plan according to the latency period attributed to a patient's primary cancer.

10.
Gland Surg ; 11(6): 970-980, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35800745

RESUMEN

Background: Examining risk factors of readmission in adrenalectomy patients and estimated the cost burden of unplanned readmission on the United States' healthcare system. Methods: According to the Nationwide Readmission Database, 20,494 patients underwent adrenalectomy between 2010-2014. Demographics, comorbidities, clinical data, length of stay (LOS), annual case volume, and discharge disposition of 30- and 90-day readmission cohorts were compared to the non-readmitted cohort. Results: A total of 1,463 (7.9%) and 1,959 (12.7%) adrenalectomy patients were readmitted at 30 and 90 days after discharge, respectively. Prolonged initial hospital stays [odds ratio (OR) =1.93; 95% confidence interval (CI): 1.63-2.27] and postoperative complications (OR =4.91; 95% CI: 1.98-12.16) were associated with a higher risk of readmission. Complications were significantly more frequent in patients with a primary or secondary malignancy (OR =1.42; 95% CI: 1.23-1.64) and in patients undergoing a procedure at a low adrenalectomy volume hospital [hazard ratio (HR) =0.75; 95% CI: 0.62-0.91; P=0.003]. Readmission extended overall LOS by an average of 2.06 days, costing an additional $18,529.49 per admission. Conclusions: Readmission adds significantly to the burden of disease after adrenalectomy. Understanding contributing factors may identify strategies to reduce readmissions and improve healthcare for patients.

11.
Cancers (Basel) ; 14(3)2022 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-35158750

RESUMEN

Triple-negative breast cancer (TNBC) is a highly aggressive form of breast cancer. Due to its heterogeneity and lack of hormone receptor expression, this subtype is more likely to metastasize and resist treatment attempts than are other forms of breast cancer. Due to the absence of targetable receptors, chemotherapy and breast conserving surgery have been the predominant treatment options for patients. However, resistance to chemotherapy and local recurrence of the tumors is frequent. Emerging immunotherapies have begun to change treatment plans for patients diagnosed with TNBC. In this review, we discuss the various immune pathways identified in TNBC and the role they play as targets for new potential treatment choices. Various therapeutic options that inhibit key pathways in cellular growth cycles, DNA repair mechanisms, epithelial mesenchymal transition, and immunosuppression have been shown to improve survival in patients with this disease. With promising results thus far, continued studies of immunotherapy and neoadjuvant therapy options for TNBC are likely to alter the treatment course for these diagnoses in the future.

12.
J Neurosci ; 41(32): 6933-6945, 2021 08 11.
Artículo en Inglés | MEDLINE | ID: mdl-34210776

RESUMEN

The orbitofrontal cortex (OFC) and hippocampus share striking cognitive and functional similarities. As a result, both structures have been proposed to encode "cognitive maps" that provide useful scaffolds for planning complex behaviors. However, while this function has been exemplified by spatial coding in neurons of hippocampal regions-particularly place and grid cells-spatial representations in the OFC have been investigated far less. Here we sought to address this by recording OFC neurons from male rats engaged in an open-field foraging task like that originally developed to characterize place fields in rodent hippocampal neurons. Single-unit activity was recorded as rats searched for food pellets scattered randomly throughout a large enclosure. In some sessions, particular flavors of food occurred more frequently in particular parts of the enclosure; in others, only a single flavor was used. OFC neurons showed spatially localized firing fields in both conditions, and representations changed between flavored and unflavored foraging periods in a manner reminiscent of remapping in the hippocampus. Compared with hippocampal recordings taken under similar behavioral conditions, OFC spatial representations were less temporally reliable, and there was no significant evidence of grid tuning in OFC neurons. These data confirm that OFC neurons show spatial firing fields in a large, two-dimensional environment in a manner similar to hippocampus. Consistent with the focus of the OFC on biological meaning and goals, spatial coding was weaker than in hippocampus and influenced by outcome identity.SIGNIFICANCE STATEMENT The orbitofrontal cortex (OFC) and hippocampus have both been proposed to encode "cognitive maps" that provide useful scaffolds for planning complex behaviors. This function is exemplified by place and grid cells identified in hippocampus, the activity of which maps spatial environments. The current study directly demonstrates very similar, though not identical, spatial representatives in OFC neurons, confirming that OFC-like hippocampus-can represent a spatial map under the appropriate experimental conditions.


Asunto(s)
Neuronas/fisiología , Corteza Prefrontal/fisiología , Conducta Espacial/fisiología , Animales , Conducta Animal/fisiología , Mapeo Encefálico/métodos , Electrocorticografía , Masculino , Ratas , Ratas Long-Evans
13.
Nat Neurosci ; 24(3): 391-400, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33589832

RESUMEN

Experimental research controls for past experience, yet prior experience influences how we learn. Here, we tested whether we could recruit a neural population that usually encodes rewards to encode aversive events. Specifically, we found that GABAergic neurons in the lateral hypothalamus (LH) were not involved in learning about fear in naïve rats. However, if these rats had prior experience with rewards, LH GABAergic neurons became important for learning about fear. Interestingly, inhibition of these neurons paradoxically enhanced learning about neutral sensory information, regardless of prior experience, suggesting that LH GABAergic neurons normally oppose learning about irrelevant information. These experiments suggest that prior experience shapes the neural circuits recruited for future learning in a highly specific manner, reopening the neural boundaries we have drawn for learning of particular types of information from work in naïve subjects.


Asunto(s)
Condicionamiento Clásico/fisiología , Miedo/fisiología , Neuronas GABAérgicas/fisiología , Área Hipotalámica Lateral/fisiología , Aprendizaje/fisiología , Animales , Señales (Psicología) , Femenino , Masculino , Vías Nerviosas/fisiología , Ratas , Ratas Long-Evans , Ratas Transgénicas , Recompensa
14.
J Neurosci ; 41(2): 342-353, 2021 01 13.
Artículo en Inglés | MEDLINE | ID: mdl-33219006

RESUMEN

Substance use disorders (SUDs) are characterized by maladaptive behavior. The ability to properly adjust behavior according to changes in environmental contingencies necessitates the interlacing of existing memories with updated information. This can be achieved by assigning learning in different contexts to compartmentalized "states." Though not often framed this way, the maladaptive behavior observed in individuals with SUDs may result from a failure to properly encode states because of drug-induced neural alterations. Previous studies found that the dorsomedial striatum (DMS) is important for behavioral flexibility and state encoding, suggesting the DMS may be an important substrate for these effects. Here, we recorded DMS neural activity in cocaine-experienced male rats during a decision-making task where blocks of trials represented distinct states to probe whether the encoding of state and state-related information is affected by prior drug exposure. We found that DMS medium spiny neurons (MSNs) and fast-spiking interneurons (FSIs) encoded such information and that prior cocaine experience disrupted the evolution of representations both within trials and across recording sessions. Specifically, DMS MSNs and FSIs from cocaine-experienced rats demonstrated higher classification accuracy of trial-specific rules, defined by response direction and value, compared with those drawn from sucrose-experienced rats, and these overly strengthened trial-type representations were related to slower switching behavior and reaction times. These data show that prior cocaine experience paradoxically increases the encoding of state-specific information and rules in the DMS and suggest a model in which abnormally specific and persistent representation of rules throughout trials in DMS slows value-based decision-making in well trained subjects.SIGNIFICANCE STATEMENT Substance use disorders (SUDs) may result from a failure to properly encode rules guiding situationally appropriate behavior. The dorsomedial striatum (DMS) is thought to be important for such behavioral flexibility and encoding that defines the situation or "state." This suggests that the DMS may be an important substrate for the maladaptive behavior observed in SUDs. In the current study, we show that prior cocaine experience results in over-encoding of state-specific information and rules in the DMS, which may impair normal adaptive decision-making in the task, akin to what is observed in SUDs.


Asunto(s)
Trastornos Relacionados con Cocaína/psicología , Cocaína/farmacología , Toma de Decisiones/efectos de los fármacos , Neostriado/efectos de los fármacos , Animales , Conducta de Elección/efectos de los fármacos , Interneuronas/efectos de los fármacos , Masculino , Neuronas/efectos de los fármacos , Odorantes , Desempeño Psicomotor/efectos de los fármacos , Ratas , Ratas Long-Evans , Tiempo de Reacción/efectos de los fármacos , Recompensa , Autoadministración , Sacarosa/farmacología
15.
Nat Commun ; 11(1): 106, 2020 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-31913274

RESUMEN

Dopamine neurons are proposed to signal the reward prediction error in model-free reinforcement learning algorithms. This term represents the unpredicted or 'excess' value of the rewarding event, value that is then added to the intrinsic value of any antecedent cues, contexts or events. To support this proposal, proponents cite evidence that artificially-induced dopamine transients cause lasting changes in behavior. Yet these studies do not generally assess learning under conditions where an endogenous prediction error would occur. Here, to address this, we conducted three experiments where we optogenetically activated dopamine neurons while rats were learning associative relationships, both with and without reward. In each experiment, the antecedent cues failed to acquire value and instead entered into associations with the later events, whether valueless cues or valued rewards. These results show that in learning situations appropriate for the appearance of a prediction error, dopamine transients support associative, rather than model-free, learning.


Asunto(s)
Dopamina/metabolismo , Neuronas Dopaminérgicas/fisiología , Aprendizaje , Animales , Conducta Animal , Condicionamiento Clásico , Señales (Psicología) , Femenino , Masculino , Modelos Neurológicos , Ratas , Recompensa
16.
Nat Commun ; 10(1): 4140, 2019 09 12.
Artículo en Inglés | MEDLINE | ID: mdl-31515501

RESUMEN

Persistent transcriptional and morphological events in the nucleus accumbens (NAc) and other brain reward regions contribute to the long-lasting behavioral adaptations that characterize drug addiction. Opiate exposure reduces the density of dendritic spines on medium spiny neurons of the NAc; however, the underlying transcriptional and cellular events mediating this remain unknown. We show that heroin self-administration negatively regulates the actin-binding protein drebrin in the NAc. Using virus-mediated gene transfer, we show that drebrin overexpression in the NAc is sufficient to decrease drug seeking and increase dendritic spine density, whereas drebrin knockdown potentiates these effects. We demonstrate that drebrin is transcriptionally repressed by the histone modifier HDAC2, which is relieved by pharmacological inhibition of histone deacetylases. Importantly, we demonstrate that heroin-induced adaptations occur only in the D1+ subset of medium spiny neurons. These findings establish an essential role for drebrin, and upstream transcriptional regulator HDAC2, in opiate-induced plasticity in the NAc.


Asunto(s)
Proteínas de Microfilamentos/metabolismo , Neuropéptidos/metabolismo , Trastornos Relacionados con Opioides/metabolismo , Animales , Conducta Animal/efectos de los fármacos , Epigénesis Genética/efectos de los fármacos , Heroína/efectos adversos , Histona Desacetilasa 2/metabolismo , Masculino , Plasticidad Neuronal/efectos de los fármacos , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Neuropéptidos/genética , Núcleo Accumbens/metabolismo , Alcaloides Opiáceos/efectos adversos , Trastornos Relacionados con Opioides/fisiopatología , Dolor/metabolismo , Ratas Sprague-Dawley , Sinapsis/efectos de los fármacos , Sinapsis/metabolismo
17.
Nat Neurosci ; 21(10): 1493, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30018354

RESUMEN

In the version of this article initially published, the laser activation at the start of cue X in experiment 1 was described in the first paragraph of the Results and in the third paragraph of the Experiment 1 section of the Methods as lasting 2 s; in fact, it lasted only 1 s. The error has been corrected in the HTML and PDF versions of the article.

19.
Glia ; 65(10): 1626-1639, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28657129

RESUMEN

Oligodendrocytes and Schwann cells not only form myelin in the central and peripheral nervous system, but also provide metabolic and trophic support to the axons they ensheathe. Acetyl-CoA is potentially a key molecule in Schwann cells and oligodendrocytes because it is at the crossroads of cellular lipid biosynthesis and energy generation. The main route for acetyl-CoA production is the oxidation of pyruvate by the pyruvate dehydrogenase complex (PDC). PDC deficiency in humans results in neurodegeneration and developmental impairments in both white and gray matter structures. To address the importance of PDC in myelinating glia, we deleted Pdha1 gene specifically in oligodendrocytes and Schwann cells. Surprisingly, sciatic and optic nerve morphology and the motor performance of Pdha1f/Y; CnpCre/+ mice are undistinguishable from those of controls at 1 month of age. In addition, myelin is stably maintained for at least 10 months. However, Pdha1f/Y; CnpCre/+ mice showed reduced fiber density and signs of axonal degeneration in both sciatic and optic nerves from 6 months of age. In contrast, 10 month-old mice bearing a floxed Pdha1 gene with either P0-Cre (expressed only by Schwann cells) or NG2-CreER (expressed in oligodendrocyte precursor cells) do not show any sign of axonal pathology or alterations in myelin structure or thickness. This indicates that the axonopathy is specific to the Pdha1f/Y; CnpCre/+ mice. Taken together, these results suggest that acetyl-CoA derived from pyruvate is not necessary for myelin maintenance and, thus, myelin-forming cells are not likely to contribute to the pathophysiology of PDC deficiency.


Asunto(s)
Acetilcoenzima A/metabolismo , Vaina de Mielina/metabolismo , Enfermedad por Deficiencia del Complejo Piruvato Deshidrogenasa/patología , Complejo Piruvato Deshidrogenasa/metabolismo , Ácido Pirúvico/metabolismo , 2',3'-Nucleótido Cíclico 3'-Fosfodiesterasa/genética , 2',3'-Nucleótido Cíclico 3'-Fosfodiesterasa/metabolismo , Adenosina Difosfato/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Antígenos/genética , Antígenos/metabolismo , Femenino , Regulación de la Expresión Génica/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Proteína P0 de la Mielina/genética , Proteína P0 de la Mielina/metabolismo , Vaina de Mielina/patología , Proteínas del Tejido Nervioso/metabolismo , Conducción Nerviosa/genética , Nervio Óptico/patología , Proteoglicanos/genética , Proteoglicanos/metabolismo , Complejo Piruvato Deshidrogenasa/genética , Enfermedad por Deficiencia del Complejo Piruvato Deshidrogenasa/genética , Enfermedad por Deficiencia del Complejo Piruvato Deshidrogenasa/fisiopatología , Nervio Ciático/patología
20.
Nat Neurosci ; 20(5): 735-742, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28368385

RESUMEN

Associative learning is driven by prediction errors. Dopamine transients correlate with these errors, which current interpretations limit to endowing cues with a scalar quantity reflecting the value of future rewards. We tested whether dopamine might act more broadly to support learning of an associative model of the environment. Using sensory preconditioning, we show that prediction errors underlying stimulus-stimulus learning can be blocked behaviorally and reinstated by optogenetically activating dopamine neurons. We further show that suppressing the firing of these neurons across the transition prevents normal stimulus-stimulus learning. These results establish that the acquisition of model-based information about transitions between nonrewarding events is also driven by prediction errors and that, contrary to existing canon, dopamine transients are both sufficient and necessary to support this type of learning. Our findings open new possibilities for how these biological signals might support associative learning in the mammalian brain in these and other contexts.


Asunto(s)
Aprendizaje por Asociación/fisiología , Neuronas Dopaminérgicas/fisiología , Área Tegmental Ventral/fisiología , Animales , Animales Modificados Genéticamente , Condicionamiento Psicológico , Señales (Psicología) , Femenino , Masculino , Ratas , Recompensa
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