Analysis of proprioceptive inputs to DPG interneurons in the cockroach.

In this study we report on morphological and physiological analysis of proprioceptive sensory input to thoracic interneurons. Sensory neurons from leg proprioceptors were filled using cobalt chloride. The morphological location of these sensory neurons was compared with that of the DPG interneurons. The interneurons investigated were found to have morphological overlap with the sensory neurons of the specific proprioceptors, suggesting that they have the potential to receive direct input from these proprioceptors. Individual interneurons were recorded intracellularly and identified by intracellular injection of Lucifer Yellow, and the responses of these cells to mechanical stimulation of specific proprioceptors were analyzed. All of the DPG interneurons tested as well as other interneurons receive input from one or more of these proprioceptors. In addition, DPG interneurons have ipsilateral/contralateral biases in their responses to proprioceptors. Paired stimulation of proprioceptors resulted in enhancement or decrement of the response in the interneurons, depending upon which sensory structures were stimulated together. The results of this study show that proprioceptive information is processed by DPG interneurons.

[1]  K. Pearson.  Central Programming and Reflex Control of Walking in the Cockroach , 1972 .

[2]  D. Sattelle,et al.  A simple technique for monitoring the synaptic actions of pharmacological agents. , 1973, The Journal of experimental biology.

[3]  G. E. Gregory.  Neuroanatomy of the mesothoracic ganglion of the cockroach Periplaneta americana (L.). I. The roots of the peripheral nerves. , 1974, Philosophical transactions of the Royal Society of London. Series B, Biological sciences.

[4]  K. Pearson,et al.  Properties of the trochanteral hair plate and its function in the control of walking in the cockroach. , 1976, The Journal of experimental biology.

[5]  J. S. Altman,et al.  A silver intensification method for cobalt-filled neurones in wholemount preparations , 1977, Brain Research.

[6]  J. Altman,et al.  The locust wing hinge stretch receptors. I. Primary sensory neurones with enormous central arborizations , 1977, The Journal of comparative neurology.

[7]  K. Krämer,et al.  Flight-inhibition on ground contact in the American cockroach, Periplaneta americana—I. Contact receptors and a model for their central connections , 1978 .

[8]  J. Kien,et al.  Intra- and intersegmental pathways active during walking in the locust , 1983, Proceedings of the Royal Society of London. Series B. Biological Sciences.

[9]  S. Collin.  The central morphology of mechanoreceptor afferents in the metathoracic leg of the cockroach, Periplaneta americana (Insecta). , 1985, Journal of neurobiology.