Contrasting walking styles map to discrete neural substrates in the mouse brainstem.

Walking is a slow gait which is particularly adaptable to meet internal or external needs and is prone to maladaptive alterations that lead to gait disorders. Alterations can affect speed, but also style (the way one walks). While slowed speed may signify the presence of a problem, style represents the hallmark essential for clinical classification of gait disorders. However, it has been challenging to objectively capture key stylistic features while uncovering neural substrates driving these features. Here we revealed brainstem hotspots that drive strikingly different walking styles by employing an unbiased mapping assay that combines quantitative walking signatures with focal, cell type specific activation. We found that activation of inhibitory neurons that mapped to the ventromedial caudal pons induced slow motion-like style. Activation of excitatory neurons that mapped to the ventromedial upper medulla induced shuffle-like style. Contrasting shifts in walking signatures distinguished these styles. Activation of inhibitory and excitatory neurons outside these territories or of serotonergic neurons modulated walking speed, but without walking signature shifts. Consistent with their contrasting modulatory actions, hotspots for slow-motion and shuffle-like gaits preferentially innervated different substrates. These findings lay the basis for new avenues to study mechanisms underlying (mal)adaptive walking styles and gait disorders.

Correlation between cord insertion type and chorionic villus vascularization of the co-twin in diamniotic-monochorionic twin pregnancies.

BACKGROUND: Recent evidence suggests that cord insertion type of one twin correlates with chorionic plate vascularization of the monochorionic co-twin. Specifically, for twins with paracentral cords, chorionic plate vascularization is significantly greater when the co-twin has a velamentous, rather than paracentral cord insertion. AIMS: To determine whether this correlation between cord insertion type and vascularization of the co-twin also extends to the deeper chorionic villus tree. STUDY DESIGN: Morphometric analysis of chorionic villus vascularization in CD31-immunostained sections of a retrospective cohort of gestational age-matched third trimester monochorionic placentas with discordant paracentral/velamentous (PC/V) or concordant paracentral/paracentral (PC/PC) cord insertions. OUTCOME MEASURES: Vascular numerical density (number of vascular profiles per unit villus stromal area) of intermediate villi (>80 µm diameter) and terminal villi (<80 µm). RESULTS: For twins with paracentral cord insertion, the vascular numerical density of intermediate villi was significantly higher for twins in a discordant PC/V relationship than for those in a concordant PC/PC relationship (P<0.05), thus replicating previous findings in superficial chorionic vessels. For terminal villi, in contrast, the vascular numerical density of twins with paracentral cords in a PC/V combination was significantly lower than of those in a PC/PC combination, and similar to that of their co-twins with velamentous cord insertion. CONCLUSIONS: Early placental angiogenesis in monochorionic twin gestations may be influenced by implantation and cord localization of the co-twin. The regulation of terminal villus angiogenesis appears to be dissociated from more proximal villus angiogenesis and independent of cord insertion of the co-twin.

Arias-Stella reaction of the cervix: The enduring diagnostic challenge.

BACKGROUND: The Arias-Stella reaction is a hormone-related atypical endometrial change characterized by hypertrophy and vacuolization of glandular epithelial cells, associated with marked nuclear pleomorphism, enlargement, and hyperchromasia. When presenting in extra-uterine sites, the differentiation of Arias-Stella changes from other more ominous clear cell lesions may pose significant difficulties. CASE REPORT: We report a case of an endocervical clear cell lesion incidentally discovered during a prenatal visit of a young pregnant woman. Interpretation of the pathological findings was complicated by the small size and fragmentation of the specimen. CONCLUSIONS: Recognition of Arias-Stella reaction in extra-uterine sites, especially in young women, is critical to avoid misdiagnosis of this innocuous lesion as clear cell adenocarcinoma. Attention to cellular and nuclear detail, as well as careful consideration of the clinical scenario, is crucial for establishment of the correct diagnosis.