1. The effects of altering sensory input on the motoneuronal activity underlying antennular flicking have been tested. 2. Removal of the short segments of the outer flagellum results in a reduction of the number of spikes/burst in the fast flexor motoneurones A31F and A32F. 3. During a flick the delay between the burst in motoneurone A31F and the burst in motoneurone A32F is insensitive to alteration of sensory input. 4. Sensory feedback from the flexion phase of a flick is necessary for the activation of either extensor motoneurone. Evidence is presented to suggest that this feedback is primarily from joint-movement receptors at the MS-DS and DS-OF joints. 5. The results are incorporated into a model in which the patterns of flexor activity result from some specified properties of three components: a trigger system, a follower system, and the spike initiating zone of the flexor motoneurones. The trigger system determines when a flick will occur. The follower system determines the number of flexor spikes during a flick. Properties of the spike initiating zone determine the spike frequency and the timing between bursts in the flexor motoneurones. Extensor activity in the model is reflexively elicited by feedback from phasic, unidirectional receptors sensitive to joint flexion. 6. The functional significance of reflex control of extensor activity is discussed in relation to the form and proposed function of antennular flicking. It is suggested that this form of control is adapted to the function of antennular flicking because flexion at the MS-DS joint is not always necessary for the fulfilment of the fuction of a flick.
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.
JEB@100: an interview with Monitoring Editor Stuart Egginton
Stuart Egginton reveals how he overcame the challenges of being a comparative physiologist in a medical school and how he would tell his younger self to trust his instincts when pursuing new ideas.
Mapping Neuromodulator expression in Octopus vulgaris – a Travelling Fellowship story
To develop her understanding of neural mapping, Federica Pizzulli, a PhD student from the Biology and Evolution of Marine Organisms Department of the Stazione Zoologica Anton Dohrn in Naples, used a Travelling Fellowship from Journal of Experimental Biology to visit the Seuntjens lab at KU Leuven, Belgium – the first lab to adapt in-situ Hybridization Chain Reaction (HCR) to Octopus vulgaris. Read more about our Travelling Fellowships here.
Revealing the secrets of sleep
Research spanning 20 years has illuminated the universal nature of sleep across species, from mammals to cnidaria. Rhea Lakhiani and colleagues explore sleep phenomenology, physiology and function through the lens of comparative physiology.
Thirsty snakes want to keep cool
Even though cooling down to digest dinner is a risky strategy - it takes longer leaving reptiles vulnerable to attack - thirsty Children's pythons find a cooler spot and now Jill Azzolini & co have discovered that the parched reptiles choose to keep cool to conserve water.
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