The perineurium was found to form the principal barrier to diffusion across the blood-brain barrier system of the cockroach, Periplaneta americana, since the resistance across this layer was much greater than that across the underlying neuroglia. An equivalent electrical circuit of the perineurium was then used to analyse recordings made in apparent perineurial cells and the interstitial system. Trans-perineurial resistance was at least 900 ωcm2, while the ratio between basolateral and apical membrane resistances was 11:1, indicating that the apical membrane had an area much greater than that of the basolateral membrane. Raising the potassium concentration in the saline produced changes in potential difference (p.d.) and resistance that were interpreted as due to the effect of potassium upon the basolateral membrane. Analysis indicated that the resting electromotive force (e.m.f.) generated by the basolateral membrane was less than that generated by the apical, although the K level in the saline was near that considered to be in the interstitial system. The analysis also yielded a value of 9 for the ratio of shunt resistance to apical resistance. Most changes in recorded values following the K elevation could be simulated by use of the estimated parameters, and an estimation of a change in interstitial K level. From these results, the shunt can be calculated to be an important contributor to the resistance across the perineurium, having a resistance about 0.9 times that of the transcellular resistance.
In the field: an interview with Harald Wolf
(update)-Conversation.jpg?versionId=3747)
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
-GSWorkshop.png?versionId=3747)
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
-NewEditor.png?versionId=3747)
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
-FilterFeeders.jpg?versionId=3747)
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
-Review.png?versionId=3747)
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.
Social media
