Arithmetic and local circuitry underlying dopamine prediction errors

Dopamine neurons are thought to facilitate learning by comparing actual and expected reward^1,2. Despite two decades of investigation, little is known about how this comparison is made. To determine how dopamine neurons calculate prediction error, we combined optogenetic manipulations with extracellular recordings in the ventral tegmental area (VTA) while mice engaged in classical conditioning. By manipulating the temporal expectation of reward, we demonstrate that dopamine neurons perform subtraction, a computation that is ideal for reinforcement learning but rarely observed in the brain. Furthermore, selectively exciting and inhibiting neighbouring GABA neurons in the VTA reveals that these neurons are a source of subtraction: they inhibit dopamine neurons when reward is expected, causally contributing to prediction error calculations. Finally, bilaterally stimulating VTA GABA neurons dramatically reduces anticipatory licking to conditioned odours, consistent with an important role for these neurons in reinforcement learning. Together, our results uncover the arithmetic and local circuitry underlying dopamine prediction errors.

The Interpretation of Repeat Positive Results for Gonorrhea and Chlamydia in Children

BACKGROUND

The diagnosis of gonorrhea and/or chlamydia in a prepubertal child beyond the neonatal period is confirmatory of mucosal contact with infective bodily secretions and therefore highly concerning for sexual abuse. When such a diagnosis is made, a report to protective authorities is warranted so that safety and potential criminal activity may be evaluated concurrent with the medical management. Occasionally, despite perceived adequate medical management and protective safety plans, a child may present with a repeat positive result for sexually transmitted infections. In this scenario, it is important for medical providers to carefully consider and be aware of the possible reasons for the repeat positive result: (1) treatment failure, (2) a new infection from repeated abuse, or (3) a false-positive result due to the limitations of nonculture testing.

CASE

Prepubertal sisters were diagnosed with gonorrhea and Chlamydia and treated with antibiotics, and the individual identified as having sexually abused them was removed from the home.

SUMMARY AND CONCLUSION

Over a 4-month period, both children continued to have positive testing for chlamydia via the nucleic acid amplification test and/or culture. Concurrent with using alternate antibiotic treatment options, protective authorities were alerted to the fact that this was likely a reinfection. The investigative team later determined that a second adult, who tested positive for gonorrhea and chlamydia, was also sexually abusing both girls. Disclosures of abuse regarding both adult individuals were deemed credible by authorities and supported with collateral information.

The impact of a hospital-based educational video on maternal perceptions and planned practices of infant safe sleep

PURPOSE

To evaluate whether an educational video would impact infant sleep practices among new mothers.

DESIGN AND METHODS

Survey responses of new mothers who did (n = 43) versus did not (n = 49) watch the educational video were compared to identify differences in observed and planned infant sleep practices.

RESULTS

Mothers who watched the video were more likely to observe safe sleep practices while in the hospital (67.4% vs. 46.9%, p < .05). They were also less likely to plan for (unsafe) side positioning (23.9% vs. 7.1%, p < .05).

PRACTICE IMPLICATIONS

Given the potentially fatal consequence of unsafe sleep, a brief video provided by nursing staff can be a prudent component of new parent education.

A study on oral mucosal lesions in 3500 patients with dermatological diseases in South India

BACKGROUND

Oral mucosal lesions that are observed in the dermatological diseases are categorized under mucocutaneous conditions. The oral lesions in dermatological diseases may be the early aspects of the disease manifestation or the most significant clinical appearance or the only sign/and or symptom of such dermatological diseases and occasionally lesions occur simultaneously in the skin as well as mucous membrane.

AIM

This present study attempts to find out the prevalence of oral mucosal lesions in patients with dermatological diseases.

SUBJECTS AND METHODS

The study includes 3500 patients who attended out-patient Department of Dermatology. Patients with oral manifestation were subjected for clinical examination in the Department of Oral Pathology. Diagnostic procedures were performed to confirm the clinical oral diagnosis. The results of the study were analyzed by SPSS software version 19.0 (Armonk, NY) and presented as descriptive statistics. Correlation of oral manifestions with their respective dermatological disease was statistically analysed by Pearson's correlation test.(P < 0.05 were considered as statistically significant).

RESULTS

The prevalence rate of oral mucosal lesions in the present study was 1.8% (65/3500). The most frequent lesions observed were psoriasis 32.3% (21/65), lichen planus 18.4% (12/65), Stevens Johnson Syndrome 18.4% (12/65), pemphigus 10.7% (7/65), toxic epidermal necrolysis 4.6% (3/65), systemic lupus erythematosus 3% (2/65), discoid lupus erythematosus 1.5% (1/65), pemphigoid 1.5% (1/65). Gender distribution in the study population was statistically significant (P < 0.001). Employed and unemployed individuals in the study population were statistically significant (P < 0.001). Pearson's correlation analysis of oral manifestations with their respective dermatological disease showed r = 0.466 and signifies a positive correlation and is statistically significant at the 0.01 level (two-tailed).

CONCLUSION

The prevalence rate of oral mucosal lesions in patients with dermatological diseases was relatively low. However, predominant oral mucosal lesions observed in the study were autoimmune in origin with a high morbidity and mortality index. Hence, multidisciplinary approach will definitely help in the prognosis of patients.