Top-down control of flight by a non-canonical cortico-amygdala pathway.

Survival requires the selection of appropriate behaviour in response to threats, and dysregulated defensive reactions are associated with psychiatric illnesses such as post-traumatic stress and panic disorder1. Threat-induced behaviours, including freezing and flight, are controlled by neuronal circuits in the central amygdala (CeA)2; however, the source of neuronal excitation of the CeA that contributes to high-intensity defensive responses is unknown. Here we used a combination of neuroanatomical mapping, in vivo calcium imaging, functional manipulations and electrophysiology to characterize a previously unknown projection from the dorsal peduncular (DP) prefrontal cortex to the CeA. DP-to-CeA neurons are glutamatergic and specifically target the medial CeA, the main amygdalar output nucleus mediating conditioned responses to threat. Using a behavioural paradigm that elicits both conditioned freezing and flight, we found that CeA-projecting DP neurons are activated by high-intensity threats in a context-dependent manner. Functional manipulations revealed that the DP-to-CeA pathway is necessary and sufficient for both avoidance behaviour and flight. Furthermore, we found that DP neurons synapse onto neurons within the medial CeA that project to midbrain flight centres. These results elucidate a non-canonical top-down pathway regulating defensive responses.

The pterygomandibular raphe: a comprehensive review.

The pterygomandibular raphe (PMR) is a tendinous structure connecting the bucinator and the superior pharyngeal constrictor muscles. With its implications in the spread of oral cancer, the proper treatment of obstructive sleep apnea, and dental procedures, it is important to obtain a thorough understanding of the PMR. We reviewed the existing literature to compile the published information regarding its anatomy, embryology, imaging, variations, functions, pathologies, and clinical relevance of the pterygomandibular raphe.

A comprehensive review of the mental spine.

Clinical case reports and research regarding the mental spines and their associated structures create a detailed picture of the floor of the mouth for assessment during clinical treatment. This compilation of information covers the mental spines, the attached geniohyoid and genioglossus muscles, the lingual foramina, and the veins and arteries of the jaw and floor of the mouth. It is important to consider the variations in the mental spines for oral and maxillofacial treatment involving the mandible. Differences in anatomy of the mental spine, including their number, location, and size, can impact diagnosis and treatment approaches.

Initial versus Staged Thyroidectomy for Differentiated Thyroid Cancer: A Retrospective Multi-Dimensional Cohort Analysis of Effectiveness and Safety.

The optimal surgical approach for differentiated thyroid cancer remains controversial, with debate regarding the comparative risks of upfront total thyroidectomy versus staged completion thyroidectomy following the initial lobectomy. This study aimed to assess the complication rates associated with these two strategies and identify the optimal timing for completion thyroidectomy using a multi-dimensional analysis of four cohorts: an institutional series (n = 148), the National Surgical Quality Improvement Program (NSQIP) database (n = 39,992), the TriNetX repository (n > 30,000), and a pooled literature review (10 studies, n = 6015). Institutional data revealed higher overall complication rates with total thyroidectomy (18.3%) compared to completion thyroidectomy (6.8%), primarily due to increased temporary hypocalcemia (10% vs. 0%, p = 0.004). The NSQIP analysis demonstrated that total thyroidectomy was associated with a 72% increased risk of transient hypocalcemia (p < 0.001) and a 25% increased risk of permanent hypocalcemia (p < 0.001). TriNetX data confirmed these findings and identified obesity and concurrent neck dissection as risk factors for complications. A meta-analysis showed that total thyroidectomy increased the rates of transient (RR = 1.63) and permanent (RR = 1.23) hypocalcemia (p < 0.001). Institutional and TriNetX data suggested that performing completion thyroidectomy between 1 and 6 months after the initial lobectomy minimized permanent complication rates compared to delays beyond 6 months. In conclusion, for differentiated thyroid cancer, total thyroidectomy is associated with higher risks of transient and permanent hypocalcemia compared to staged completion thyroidectomy. However, performing completion thyroidectomy within 1-6 months of the initial lobectomy may mitigate the risk of permanent complications. These findings can inform personalized surgical decision-making for patients with differentiated thyroid cancer.

Sex differences in behavioral responses during a conditioned flight paradigm.

Females exhibit greater susceptibility to trauma- and stress-related disorders compared to males; therefore, it is imperative to study sex differences in the mode and magnitude of defensive responses in the face of threat. To test for sex differences in defensive behavior, we used a modified Pavlovian fear conditioning paradigm that elicits clear transitions between freezing and flight behaviors within individual subjects. Female mice subjected to this paradigm exhibited more freezing behavior compared to males, especially during the intertrial interval period. Female mice also exhibited more freezing in response to conditioned auditory stimuli in the last block of extinction training. Furthermore, there were sex differences in the expression of other adaptive behaviors during fear conditioning. Assaying rearing, grooming, and tail rattling behaviors during the conditioned flight paradigm yielded measurable differences across sessions and between males and females. Overall, these results provide insight into sex-dependent alterations in mouse behavior induced by fear conditioning.