Octopaminergic sensitivity of the glia that form the blood-brain barrier of the cockroach was examined using microelectrode recordings of the potential developed across this barrier layer, the perineurium. Exposure to 10−4moll−1 DL-octopamine had no significant effect upon the changes in potential induced by substitution of Tris for external sodium. Treatment with concentrations ranging from 10−4moll−1 down to 5 × 10−7 moll−1 enhanced the resting level of the potential after 5 min, with an accompanying depression of the magnitude of potassium-induced steps. At 10−7 moll−1, there was no significant effect upon the resting level, but there was a reduction in potassium sensitivity. In a study of the effect of other neurohormonal factors, it was found that DL-synephrine could depress the response to potassium but was less effective than octopamine. In contrast, carbamylcholine, histamine and some compounds related to octopamine enhanced the potassium sensitivity. The effect of octopamine was completely blocked by phentolamine, and partially blocked by propranolol. It is concluded that the perineurium possesses an octopamine receptor that could respond to octopamine circulating in the haemolymph, and which appears to mediate a reduction in the potassium sensitivity of the basolateral membrane of these glia.
In the field: an interview with Harald Wolf
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In our new Conversation, Harald Wolf talks about his fieldwork experiences working with desert ants in Tunisia to understand their navigation.
Propose a new Workshop
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Our Workshops bring together leading experts and early-career researchers from a range of scientific backgrounds. Applications are now open to propose Workshops for 2024, one of which will be held in a Global South country.
Julian Dow steps down and John Terblanche joins the JEB team
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After 15 years with the journal, Julian Dow from University of Glasgow, UK, is stepping down as a Monitoring Editor. We wish Julian all the best for the future and welcome John Terblanche, Stellenbosch University, South Africa, who is joining the team. Julian talks about his long association with The Company of Biologists and the journal and John tells us about his life and career in this News article.
The capture of crude oil droplets by filter feeders at high and low Reynolds numbers
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Researchers from the University of Montreal, Canada, reveal how tiny filter feeding barnacles and Daphnia entrap and consume minute droplets of crude oil, introducing the pollutant at the bottom of the food chain.
Patterns and processes in amphibious fish
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In their Review, Keegan Lutek, Cassandra Donatelli and Emily Standen discuss the biomechanics and neural control of terrestrial locomotion in amphibious fish. They explore how locomotor mode depends on body shape, physical constraints and phylogeny.
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