- 1.
In the honey-bee drone retina (Apis mellifera) oxidative metabolism iscarried out largely by the photoreceptors. We have studied the effects of atransient inhibition of this metabolism, by recording receptor potentialsimultaneously with measurements of local Poo2 and extracellular [K+]([K+]o), using O2- and K+-sensitive microelectrodes.
- 2.
When the retina was subjected to anoxia or exposed to Na-amobarbital(amytal), the photoreceptors depolarized by about 30 mV, in parallel withan increase of [K+]o of up to 30 mmol l−1, and the receptor potential wasabolished in 2–3 min.
- 3.
The reduction of the receptor potential followed the beginning ofanoxia with a delay, which we define as a ‘resistance’ of the photoreceptorsto anoxia.
- 4.
The resistance to anoxia was greater if the photoreceptors werestimulated with only low intensity light flashes, suggesting that the effectsof anoxia are due to the progressive consumption of a substance stored in thephotoreceptors. This substance is probably ATP.
- 5.
When O2 was reintroduced, or amytal washed out, oxidative metabolismrapidly resumed. [K+]o quickly decreased and, after a large undershoot, returned to the baseline in less than 5 min. There was in parallel arepolarization of the photoreceptors, followed by recovery of the receptorpotential.
- 6.
About 5 min after reintroduction of O2, when the [K+]o, the membranepotential and the amplitude and kinetics of the receptor potential had completelyrecovered, exposure of the retina to a second anoxia suppressed thereceptor potential faster than had the first anoxia.
- 7.
Full recovery of the resistance to anoxia thus takes longer (by about 10 min) than recovery of the electrical properties of the photoreceptor cells.The amplitude of the extra oxygen consumption measured after a flash oflight recovered in parallel with the resistance to anoxia.
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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