- 1.
The effects of cholinergic and monoaminergic drugs and blocking agents on luminescence responses of the comb-jelly Mnemiopsis leidyi were investigated, using isolated strips of meridional cells.
- 2.
Catecholamines elicited dose-dependent flash activity and adrenalin was the most patent. The adrenalin response was abolished by propranolol (0.1 mmol l−1), but not phentolamine. Reserpine (0.1 mmol l−1) suppressed the flash response to electrical stimulation without affecting the adrenalin response.
- 3.
Acetylcholine (ACh) elicited flash activity which was propagated along the meridional canals. Eserine (0.01 mmol l−1) potentiated the flash response to either ACh or electrical stimulation.
- 4.
Tubocurarine reduced or abolished responses to either ACh or electrical stimulation. Atropine elicited intense flash activity and potentiated the response to electrical stimulation, but failed to block the ACh response.
- 5.
Prolonged exposure of meridional canals to serotonin (5-HT) depressed or abolished flash responses to ACh, adrenalin and electrical stimulation.
- 6.
The ACh flash response was abolished by propranolol but the response to adrenalin was not altered by tubocurarine. It is concluded that nicotinic cholinergic and beta-adrenergic mechanisms are interrelated and indirectly involved in excitation of luminescence in Mnemiopsis.
In the field: an interview with Martha Muñoz
Martha Muñoz is an Assistant Professor at Yale University, investigating the evolutionary biology of anole lizards and lungless salamanders. In our new Conversation, she talks about her fieldwork in Indonesia, Costa Rica, the Dominican Republic and the Appalachian Mountains, including a death-defying dash to the top of a mountain through an approaching hurricane.
Call for new preLighters
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preLights is the preprint highlighting community supported by The Company of Biologists. At the heart of preLights are our preLighters: early-career researchers who select and write about interesting new preprints for the research community. We are currently looking for new preLighters to join our team. Find out more and apply here.
Graham Scott in conversation with Big Biology
Graham Scott talks to Big Biology about the oxygen cascade in mice living on mountaintops, extreme environments for such small organisms. In this JEB-sponsored episode, they discuss the concept of symmorphosis and the evolution of the oxygen cascade.
Trap-jaw ants coordinate tendon and exoskeleton for perfect mandible arc
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Trap-jaw ants run the risk of tearing themselves apart when they fire off their mandibles, but Greg Sutton & co have discovered that the ants simultaneously push and pull the mandibles using energy stored in a head tendon and their exoskeleton to drive the jaws in a perfect arc.
Hearing without a tympanic ear
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In their Review, Grace Capshaw, Jakob Christensen-Dalsgaard and Catherine Carr explore the mechanisms of hearing in extant atympanate vertebrates and the implications for the early evolution of tympanate hearing.
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