Spinal neuron diversity scales exponentially with swim-to-limb transformation during frog metamorphosis.

Vertebrates exhibit a wide range of motor behaviors, ranging from swimming to complex limb-based movements. Here we take advantage of frog metamorphosis, which captures a swim-to-limb-based movement transformation during the development of a single organism, to explore changes in the underlying spinal circuits. We find that the tadpole spinal cord contains small and largely homogeneous populations of motor neurons (MNs) and V1 interneurons (V1s) at early escape swimming stages. These neuronal populations only modestly increase in number and subtype heterogeneity with the emergence of free swimming. In contrast, during frog metamorphosis and the emergence of limb movement, there is a dramatic expansion of MN and V1 interneuron number and transcriptional heterogeneity, culminating in cohorts of neurons that exhibit striking molecular similarity to mammalian motor circuits. CRISPR/Cas9-mediated gene disruption of the limb MN and V1 determinants FoxP1 and Engrailed-1, respectively, results in severe but selective deficits in tail and limb function. Our work thus demonstrates that neural diversity scales exponentially with increasing behavioral complexity and illustrates striking evolutionary conservation in the molecular organization and function of motor circuits across species.

Mating-induced release of oxytocin in the mouse lateral septum: Implications for social fear extinction.

In mammals, some physiological conditions are associated with the high brain oxytocin (OXT) system activity. These include lactation in females and mating in males and females, both of which have been linked to reduced stress responsiveness and anxiolysis. Also, in a murine model of social fear conditioning (SFC), enhanced brain OXT signaling in lactating mice, specifically in the lateral septum (LS), was reported to underlie reduced social fear expression. Here, we studied the effects of mating in male mice on anxiety-related behaviour, social (and cued) fear expression and its extinction, and the activity of OXT neurons reflected by cFos expression and OXT release in the LS and amygdala. We further focused on the involvement of brain OXT in the mating-induced facilitation of social fear extinction. We could confirm the anxiolytic effect of mating in male mice irrespective of the occurrence of ejaculation. Further, we found that only successful mating resulting in ejaculation (Ej+) facilitated social fear extinction, whereas mating without ejaculation (Ej-) did not. In contrast, mating did not affect cues fear expression. Using the cellular activity markers cFos and pErk, we further identified the ventral LS (vLS) as a potential region participating in the effect of ejaculation on social fear extinction. In support, microdialysis experiments revealed a rise in OXT release within the LS, but not the amygdala, during mating. Finally, infusion of an OXT receptor antagonist into the LS before mating or into the lateral ventricle (icv) after mating demonstrated a significant role of brain OXT receptor-mediated signaling in the mating-induced facilitation of social fear extinction.

Embolic Pneumonectomy for the Treatment of Proximal Pulmonary Artery Pseudoaneurysm.

Pulmonary artery pseudoaneurysm is an uncommon and potentially fatal abnormality. It has been described from a wide variety of etiologies, including infectious, iatrogenic, neoplastic, congenital, and traumatic causes. There are currently no published consensus guidelines for the diagnostic testing and management of pulmonary artery pseudoaneurysm. This case report presents an uncommon case of pulmonary artery pseudoaneurysm emerging from a non-small cell lung cancer that was successfully managed using coil embolization.

Exploring Factor Model Parameters across Continuous Variables with Local Structural Equation Models.

Using an empirical data set, we investigated variation in factor model parameters across a continuous moderator variable and demonstrated three modeling approaches: multiple-group mean and covariance structure (MGMCS) analyses, local structural equation modeling (LSEM), and moderated factor analysis (MFA). We focused on how to study variation in factor model parameters as a function of continuous variables such as age, socioeconomic status, ability levels, acculturation, and so forth. Specifically, we formalized the LSEM approach in detail as compared with previous work and investigated its statistical properties with an analytical derivation and a simulation study. We also provide code for the easy implementation of LSEM. The illustration of methods was based on cross-sectional cognitive ability data from individuals ranging in age from 4 to 23 years. Variations in factor loadings across age were examined with regard to the age differentiation hypothesis. LSEM and MFA converged with respect to the conclusions. When there was a broad age range within groups and varying relations between the indicator variables and the common factor across age, MGMCS produced distorted parameter estimates. We discuss the pros of LSEM compared with MFA and recommend using the two tools as complementary approaches for investigating moderation in factor model parameters.