Postural interneurons in the abdominal nervous system of lobster
- 28 February 1986
- journal article
- research article
- Published by Springer Nature in Journal of Comparative Physiology A
- Vol. 158 (2) , 281-290
- https://doi.org/10.1007/bf01338571
Abstract
Summary 1. The multisegmented abdomen of crayfish and lobster assumes a variety of postures as components of different behavioral acts. Experimentally these postures can be maintained by activating any of a number of premotor positioning interneurons. The pathways by which the motor output in two or more segments is coordinated were here investigated for a small group of identified postural interneurons whose somata lie in the 2nd abdominal ganglion (A2). 2. Stimulation of all postural interneurons examined evokes a motor output in other abdominal ganglia through which the axon of the neuron passes as well as in the ganglion of origin (ganglion containing the neuron's cell body). The spread of motor excitation away from the originating ganglion occurs via two general pathways. 3. In the first pathway connections to postural motoneurons are made directly by processes of the postural interneuron which pass into ganglia distal to the originating ganglion. Examples of this are shown for two flexion producing interneurons (FPIs) 201 and 301. Each of these FPIs makes monosynaptic connections with motoneurons in A2 and with a homologous set of motoneurons in A3. 4. All postural interneurons fired a set of corollary discharge interneurons (CDIs) whose activities were recorded from the abdominal connectives. Two FPIs, 202 and 301, and a third interneuron, 503, produced motor outputs in ganglia to which they did not project. The motor specificity established in A2 by stimulation of FPIs 202 and 301 (whose axons pass caudally) was preserved in more rostral ganglia, such as A1. Therefore, different sets of CDIs can be specifically recruited to spread the same motor program that is initiated in the originating ganglion to ganglia that do not receive projections from the stimulated postural interneuron. 5. CDIs, in addition, have the capacity to elicit motor programs in distal ganglia that are markedly different from that expressed in the ganglion of origin. For example, although 503 produced an inhibitory output in the abdominal ganglia that it innervated (A1 and A2), a flexion response was generated by it in more caudal ganglia. The caudal flexion response was mediated in part through a monosynaptic activation of FPI 201 and through other unidentified CDIs. Thus, the interneuronal circuitry for postural control is composed of numerous components, some of which have regional control over different portions of the abdominal nerve cord. Depending upon the required movement, select components are coactivated, either serially or in parallel, to effect a variety of spatially distinct positions.Keywords
This publication has 13 references indexed in Scilit:
- Postural interneurons in the abdominal nervous system of lobsterJournal of Comparative Physiology A, 1986
- Postural interneurons in the abdominal nervous system of lobsterJournal of Comparative Physiology A, 1986
- Synaptic interactions between neurons involved in the production of abdominal posture in crayfishJournal of Comparative Physiology A, 1985
- The organization of flexion‐evoking interneurons in the abdominal nerve cord of the crayfish, Procambarus clarkiiJournal of Experimental Zoology, 1983
- Interneurons in the flight system of the locust: Distribution, connections, and resetting propertiesJournal of Comparative Neurology, 1983
- Interneurons involved in abdominal posture in crayfish: Structure, function and command fiber responsesJournal of Comparative Physiology A, 1982
- Interneurons between giant axons and motoneurons in crayfish escape circuitryJournal of Neurophysiology, 1981
- Analysis of postural motoneuron activity in crayfish abdomen. I. Coordination by premotoneuron connectionsJournal of Neurophysiology, 1975
- Command interneurons controlling swimmeret movements in the lobster. II. Interaction of effects on motoneurons.Journal of Neurophysiology, 1972
- The central nervous organization underlying control of antagonistic muscles in the crayfish. II. Coding of position by command fibersJournal of Experimental Zoology, 1967