Etripamil Nasal Spray: Therapeutic Potential for Treating Paroxysmal Supraventricular Tachycardia.

Patients with arrythmias are at an increased risk of heart-related comorbidities and complications. Specifically, patients with paroxysmal supraventricular tachycardia (PSVT), a type of arrythmia, are at increased risk of lightheadedness or shortness of breath, due to the increased rate of the heartbeat. Most patients are prescribed oral medications to control their heart rates and maintain a normal heart rhythm. Researchers have been tasked with discovering alternative treatment options with new delivery methods to treat arrythmias such as PSVT. A nasal spray was subsequently designed and is currently undergoing clinical studies. This review aims to present and discuss the current clinical and scientific evidence pertaining to etripamil.

Food-Seeking Behavior Is Mediated by Fos-Expressing Neuronal Ensembles Formed at First Learning in Rats.

Neuronal ensembles in the infralimbic cortex (IL) develop after prolonged food self-administration training. However, rats demonstrate evidence of learning the food self-administration response as early as day 1, with responding quickly increasing to asymptotic levels. Since the contribution of individual brain regions to task performance shifts over the course of training, it remains unclear whether IL ensembles are gradually formed and refined over the course of extensive operant training, or whether functionally-relevant ensembles might be recruited and formed as early as the initial acquisition of food self-administration behavior. Here, we aimed to determine the role of IL ensembles at the earliest possible point after demonstrable learning of a response-outcome association. We first allowed rats to lever press for palatable food pellets and stopped training rats once their behavior evidenced the response-outcome association (learners). We compared their food-seeking behavior and neuronal activation (Fos protein expression) to similarly trained rats that did not form this association (non-learners). Learners had greater food-seeking behavior and neuronal activation within the medial prefrontal cortex (mPFC), suggesting that mPFC subregions might encode initial food self-administration memories. To test the functional relevance of mPFC Fos-expressing ensembles to subsequent food seeking, we tested region-wide inactivation of the IL using muscimol+baclofen and neuronal ensemble-specific ablation using the Daun02 inactivation procedure. Both region-wide inactivation and ensemble-specific inactivation of the IL significantly decreased food seeking. These data suggest that IL neuronal ensembles form during initial learning of food self-administration behavior, and furthermore, that these ensembles play a functional role in food seeking.