Olfactory inputs modulate respiration-related rhythmic activity in the prefrontal cortex and freezing behavior.
Nat Commun. 2018 Apr 18;9(1):1528
Authors: Moberly AH, Schreck M, Bhattarai JP, Zweifel LS, Luo W, Ma M
Respiration and airflow through the nasal cavity are known to be correlated with rhythmic neural activity in the central nervous system. Here we show in rodents that during conditioned fear-induced freezing behavior, mice breathe at a steady rate (~4 Hz), which is correlated with a predominant 4-Hz oscillation in the prelimbic prefrontal cortex (plPFC), a structure critical for expression of conditioned fear behaviors. We demonstrate anatomical and functional connections between the olfactory pathway and plPFC via circuit tracing and optogenetics. Disruption of olfactory inputs significantly reduces the 4-Hz oscillation in the plPFC, but leads to prolonged freezing periods. Our results indicate that olfactory inputs can modulate rhythmic activity in plPFC and freezing behavior.
PMID: 29670106 [PubMed - in process]
Internal Laryngocele: Unusual onset in a 91-year-old female patient.
Sultan Qaboos Univ Med J. 2018 Feb;18(1):e104-e106
Authors: Spinosi MC, Mezzedimi C, Monciatti G, Passali D
While internal laryngoceles rarely cause major clinical complaints, they may lead to airway obstruction and require emergency intervention on rare occasions. We report a 91-year-old patient who was referred to the Ear, Nose & Throat Clinic of the Policlinico Santa Maria alle Scotte, Siena, Italy, in 2017 due to recurrent episodes of severe dyspnoea. A flexible nasopharyngolaryngoscopic examination revealed an internal laryngocele of approximately 1.5 cm in diameter that moved up and down the glottic plane, occasionally invading the subglottic space during inspiration and impeding airflow. This caused cyanosis and dyspnoea so severe that an emergency tracheotomy was considered. Luckily, after considerable effort, the patient was able to cough, causing the mass to move above the vocal plane and allowing normal breathing. The laryngocele was subsequently removed via laryngomicrosurgery. Although the incidence of internal laryngoceles is quite rare, physicians should consider this potentially life-threatening condition among patients with dyspnoea.
PMID: 29666691 [PubMed - in process]