Cholinergic signaling at the body wall neuromuscular junction distally inhibits feeding behavior in Caenorhabditis elegans.

Complex biological functions within organisms are frequently orchestrated by systemic communication between tissues. In the model organism Caenorhabditis elegans, the pharyngeal and body wall neuromuscular junctions are two discrete structures that control feeding and locomotion, respectively. Separate, the well-defined neuromuscular circuits control these distinct tissues. Nonetheless, the emergent behaviors, feeding and locomotion, are coordinated to guarantee the efficiency of food intake. Here, we show that pharmacological hyperactivation of cholinergic transmission at the body wall muscle reduces the rate of pumping behavior. This was evidenced by a systematic screening of the effect of the cholinesterase inhibitor aldicarb on the rate of pharyngeal pumping on food in mutant worms. The screening revealed that the key determinants of the inhibitory effect of aldicarb on pharyngeal pumping are located at the body wall neuromuscular junction. In fact, the selective stimulation of the body wall muscle receptors with the agonist levamisole inhibited pumping in a lev-1-dependent fashion. Interestingly, this response was independent of unc-38, an alpha subunit of the nicotinic receptor classically expressed with lev-1 at the body wall muscle. This implies an uncharacterized lev-1-containing receptor underpins this effect. Overall, our results reveal that body wall cholinergic transmission not only controls locomotion but simultaneously inhibits feeding behavior.

Using reflective practice to support PhD students in the biosciences.

Postgraduate study can be mentally, physically and emotionally challenging. The levels of anxiety and depression in postgraduate students are much higher than those in the general population, and isolation can also be a problem, especially for students who are marginalised due to gender, race, sexuality, disability or being a first-generation and/or international student. These challenges are not new, but awareness of them has increased over the past decade, as have efforts by institutions to make students feel supported. Under the umbrella of a Doctoral Training Partnership, we developed a programme in which reflective practice is employed to help postgraduate students navigate work environments, deal with difficult supervisory or professional relationships, and improve their work-life balance. Additionally, this reflective practice is allowing the training partnership to tailor support to its students, enabling them to effectively nurture our next generation of bioscientists.