https://www.selleckchem.com/products/AT7519.html Our data indicate that pharmacological activation of midbrain dopamine neurons using a ghrelin receptor agonist does not affect auditory fear extinction. We also investigated the effect of non-pharmacological manipulation of the ghrelin system on auditory fear processing. However, we found that neither overnight food deprivation nor genetic ablation of the ghrelin receptor had a significant effect on auditory fear extinction. We conclude that the effects of manipulation of the ghrelin system on fear processing are subject to boundary conditions that remain poorly understood. This article is protected by copyright. All rights reserved.Previous results show that juvenile shortnose sturgeon are steady swimmers and, compared with salmonids, generally have low critical swimming (UCrit) and endurance swimming capacities. Most studies on swimming capacities of sturgeon, and other fishes, include those where fish have only been swum once and metrics of swimming performance are assessed (e.g., time swum, speed achieved). Under natural conditions, there are ample instances where fish would undergo multiple swimming cycles when traversing fish ways, culverts and other sources of fast water flow. While some evidence exists for salmonids, the effects of repeat swimming are not well known for sturgeon. The current study consisted of two experiments. The first examined the critical swimming (UCrit) of juvenile shortnose sturgeon following 3 consecutive swimming trials with a 30 minute recovery period between subsequent tests. The second examined the endurance swimming capacities of juvenile shortnose sturgeon following 3 consecutive swimming trials with a 60 minute recovery period between subsequent tests. Our findings indicate that (i) UCrit was consistent (~2 Body lengths/s) among swimming trials; (ii) significant individual variation exists between individuals in the endurance swimming trials; and (iii) consistent results exist f