The spontaneous burst discharges of isolated lobster (Homarus americanus) cardiac ganglia were recorded with a spaced array of electrodes. Small regions (less than 1 mm) of the ganglion were exposed to the cardioexcitor neurohormone in extracts of pericardial organs (XPO) or to 10(−5) M 5-hydroxytryptamine (5HT). All axons were excited (increased mean firing frequency, f) by both substances, but only by applications in the region between the soma (but excluding it) and proximal site of impulse initiation. Units not so exposed changed their f relatively little despite f increases of as much as threefold in exposed units and changes in burst rate and overall length. Regularity and grouping of all impulse activity into bursts was never disturbed. 5HT increases burst rate at any point of application. The increases are larger if small cells are affected than if only large cells are exposed. Burst length decreases except when the pacemaker is affected. In contrast, XPO affects neither burst rate or length unless small cells are affected. Length is increased if non-pacemaker small cells are affected; both rate and length increase if the pacemaker is affected. The pacemaker usually exhibits an f of intermediate value. Rate changes are not simply related to its f. A small cell can “burst” in the absence of impulses from any other cells. XPO may enhance endogenous “driver potentials,” while 5HT may excite by depolarizing at limited sites.
Meet the JEB Editors @ SEB 2023
New funding schemes for junior faculty staff
In celebration of our 100th anniversary, JEB has launched two new grants to support junior faculty staff working in animal comparative physiology and biomechanics who are within five years of setting up their first lab/research group. Check out our ECR Visiting Fellowships and Research Partnership Kickstart Travel Grants. First deadline for applications is 15 July 2023.
JEB@100: an interview with Monitoring Editor Katie Gilmour
Katie Gilmour tells us how she first encountered the JEB Editorial team as a graduate student at the University of Cambridge, UK, and how she would like to have a Star Trek tricorder to monitor fish non-invasively in the field.
The Forest of Biologists
The Forest of Biologists is a biodiversity initiative created by The Company of Biologists, with support from the Woodland Trust. For every Research and Review article published in Journal of Experimental Biology a native tree is planted in a UK forest. In addition to this we are protecting and restoring ancient woodland and are dedicating these trees to our peer reviewers. Visit our virtual forest to learn more.
Centenary Review - Adaptive echolocation behavior
Cynthia F. Moss and colleagues Review the behaviours used by echolocating mammals to track and intercept moving prey, interrogate dynamic sonar scenes, and exploit visual and passive acoustic stimuli.
Crucial DNA at crux of insect wing size evolution
Keity Farfán-Pira and colleagues have revealed that a tiny region of regulatory DNA in the vestigial gene governs whether insect wings are large or small and has played a key role in the evolution of insect wing size.
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