A variety of mechanisms underlie the specification of synaptic connections during development. In the monosynaptic stretch reflex in vertebrates, sensory neurones innervating muscle spindles are not determined until they make contact with a particular muscle. Instead, the muscle they supply appears to specify the pattern of central connections they establish with motoneurones. Developing thoracic sensory neurones made to project to novel peripheral targets in the forelimb of tadpoles project into the brachial spinal cord, something they never do in normal frogs. Moreover, these foreign sensory neurones make monosynaptic connections with the now functionally appropriate brachial motoneurones. Normal patterns of neuronal activity are not necessary for the formation of specific central connections. Neuromuscular blockade of developing chick embryos with curare during the period of synaptogenesis does not prevent the formation of correct sensory-motor connections. Competitive interactions among the afferent fibres also do not appear to be important in this process. When the number of sensory neurones projecting to the forelimb is drastically reduced during development, each afferent fibre still makes central connections of the same strength and specificity as normal. Together, these results suggest that peripheral targets induce some molecular change in developing sensory neurones such that they can recognize their appropriate synaptic partners in the spinal cord.
Specification of synaptic connections mediating the simple stretch reflex
E. Frank, B. Mendelson; Specification of synaptic connections mediating the simple stretch reflex. J Exp Biol 1 October 1990; 153 (1): 71–84. doi: https://doi.org/10.1242/jeb.153.1.71
Download citation file:
Advertisement
Cited by
In the field: an interview with Harald Wolf
(update)-Conversation.jpg?versionId=3772)
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=3772)
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=3772)
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.
An accelerometer-derived ballistocardiogram method for detecting heart rate in free-ranging marine mammals
-Whales.jpg?versionId=3772)
Max Czapanskiy and co show how the resting heart rates of blue whales are immortalized in the accelerometry traces collected by motion sensing data tags.
Global change and physiological challenges for Amazonian fish
-Review.png?versionId=3772)
In their Review, Adalberto Luis Val and Chris Wood discuss the physiological threats to the unique and diverse fish fauna of Amazonia.