Summary
Retrograde cobalt filling followed by silver intensification revealed new features of the anatomy of neurons which project from the brain to the corpus cardiacum (CC) of the fifth instar larva of Manduca sexta. Filling via the fused nervi corporis cardiaci (NCC) I+II demonstrated four groups of cell bodies (Ia, Ib, II, and III) previously described by Nijhout (1975), plus three major axonal tracts (A, B, and C), and four previously unobserved areas of dendritic branching, dendritic fields (DF) 1, 2, 3, and 4. Tract C is unusual in that it originates from cell bodies on the side contralateral to the filled nerve, travels ventrally and crosses over to the ipsilateral side where it turns dorsally, forming a hook in the center of the brain. It then turns ventrally again to join with tract A. DF 1 and 2 are located ventrally on the ipsilateral and contralateral sides of the brain respectively. DF 3 and 4 are situated in the dorsal protocerebrum, on the ipsilateral and contralateral sides respectively.
Fills via the NCC III revealed one cell group (IV) and a fifth dendritic field (DF 5). Simultaneous fills of both the fused NCC I+II and the NCC III showed an overlapping of DF 1 and 5, indicating the possibility of synaptic connections between these two fields.
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References
Adiyodi KG, Bern HA (1968) Neuronal appearance of neurosecretory cells in the pars intercerebralis of Periplaneta americana (L). Gen Comp Endocrinol 11:88–91
Agui N, Granger NA, Gilbert LI, Bollenbacher WE (1979) Cellular localization of the insect prothoracicotropic hormone: In vitro assay of a single neurosecretory cell. Proc Natl Acad Sci USA 76:5694–5698
Bell RA, Joachim FG (1976) Techniques for rearing laboratory colonies of tobacco hornworms and pink bollworms. Ann Ent Soc Amer 69:365–373
Bollenbacher WE, Agui N, Granger NA, Gilbert LI (1979) In vitro activation of insect prothoracic glands by the prothoracicotropic hormone. Proc Natl Acad Sci USA 76:5148–5152
Borg TK, Bell RA (1977) Ultrastructure of the neurosecretory cells in the brain of diapausing pupae of the tobacco hornworm, Manduca sexta (L). Tissue and Cell 9:567–574
Ephrussi B, Beadle GW (1936) A technique of transplantation for Drosophila. Am Nat 70:218–225
Fraser J, Pipa R (1977) Corpus allatum regulation during the metamorphosis of Periplaneta americana: Axon pathways. J Insect Physiol 23:975–984
Geldiay S, Edwards JS (1973) The protocerebral neurosecretory system and associated cerebral neurohemal area of Acheta domesticus. Z Zellforsch 145:1–22
Gibbs D, Riddiford LM (1977) Prothoracicotropic hormone in Manduca sexta: localization by a larval assay. J Exp Biol 66:255–266
Girardie J (1973) Aspects histologique, histochimique et ultrastructural des péricaryones neurosécréteurs latéraux du protocérébron de Locusta migratoria migratorioides (Insecte: Orthoptère). Z Zellforsch 141:75–91
Goodman CS (1976) Anatomy of the ocellar interneurons of acridid grasshoppers. I. The large interneurons. Cell Tissue Res 175:183–202
Highnam KC, West MW (1971) The neuropilar neurosecretory reservoir of Locusta migratoria migratorioides R & F. Gen Comp Endocrinol 16:574–585
Kater SB, Nicholson C, Davis WJ (1973) A guide to intracellular staining techniques. In: Kater SB, Nicholson C (eds) Intracellular Staining in Neurobiology. Springer, New York Heidelberg Berlin, pp 307–325
Mason CA (1973) New features of the brain-retrocerebral neuroendocrine complex of the locust Schistocerca vaga (Scudder). Z Zellforsch 141:19–32
Nijhout HF (1975) Axonal pathways in the brain-retrocerebral neuroendocrine complex of Manduca sexta (L) (Lepidoptera: Sphingidae). Int J Insect Morphol Embryol 4:529–538
Pitman RM (1979) Block intensification of neurones stained with cobalt sulphide: a method for destaining and enhanced contrast. J Exp Biol 78:295–297
Pitman RM, Tweedle CD, Cohen MJ (1972) Branching of central neurons: intracellular cobalt injection for light and electron microscopy. Science 176:412–414
Rademakers LHPM (1977) Identification of a secretomotor centre in the brain of Locusta migratoria, controlling the secretory activity of the adipokinetic hormone producing cells of the corpus cardiacum. Cell Tissue Res 184:381–395
Schooneveld H (1974) Ultrastructure of the neurosecretory system of the Colorado potato beetle, Leptinotarsa decemlineata (Say). II. Pathways of axonal secretion, transport, and innervation of neurosecretory cells. Cell Tissue Res 154:289–301
Stewart PA, Baumhover AH, Bennet LS, Hobgood Jr JM (1970) A method of sexing larvae of tobacco and tomato hornworms. J Econ Entomol 63:994–995
Strausfeld NI, Obermayer M (1976) Resolution of intraneuronal and transynaptic migration of cobalt in the insect visual and central nervous systems. J Comp Physiol 110:1–12
Truman JW, Riddiford LM (1974) Physiology of insect rhythms. III. The temporal organization of the endocrine events underlying pupation of the tobacco hornworm. J Exp Biol 60:371–382
Tyrer NM, Bell EM (1974) The intensification of cobalt-filled neurone profiles using a modification of Timm's sulphide-silver method. Brain Res 73:151–155
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Supported by NIH grant AI 15139-01 to D.G.
We are grateful to Dr. H.F. Nijhout for a critical reading of the manuscript. We thank Cliff Chan for rearing the hornworms
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Buys, C.M., Gibbs, D. The anatomy of neurons projecting to the corpus cardiacum from the larval brain of the tobacco hornworm, Manduca sexta (L.). Cell Tissue Res. 215, 505–513 (1981). https://doi.org/10.1007/BF00233527
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DOI: https://doi.org/10.1007/BF00233527