Summary
Quantitative aspects of the microanatomy of the pineal gland and other neuroendocrine and circumventricular structures were studied in a small, reproductively suppressed, female Naked Mole-rat from central Kenya, Africa. The atrophic pineal is the smallest in absolute size (0.002135 mm3) of any so far described in a species of rodent, and in size relative to body weight is second only to that of another tropical species. The subcommissural organ and posterior collicular recess are also relatively small and less well differentiated than those in most other examined rodent species. In contrast, the subfornical organ, OVLT and median eminence are large and well vascularized. It is concluded that the pineal in this species follows the previously described trend among rodents of relatively smaller size in species whose centers of distribution are in lower latitudes. Although the pineal is atrophic, the Naked Mole-rat still exhibits 24-hour and seasonally timed patterns of behavior and seasonal reproduction. However, in this species these events are probably cued by moisture, temperature and social factors rather than by photic information.
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Hill, W. C. Osman, Porter, A., Bloom, R. T., Seago, J., Southwick, M. D.: Field and laboratory studies on the Naked Mole Rat,Heterocephalus glaber. Proc. Zool. Soc. Lond.128, Part 4, 455–514 (1957).
Jarvis, J. U. M.: The breeding season and litter size of African Mole-rats. J. Reprod. Fert., Suppl.6, 237–248 (1969).
Jarvis, J. U. M.: Energetics of survival inHeterocephalus glaber (Rüppell), the Naked Mole-rat (Rodentia: Bathyergidae). Bull. Carnegie Mus. Nat. Hist.6, 81–87 (1978).
Legait, H., Bauchot, R., Stephan, H., Contet-Audonneau, J.-L.: Étude des corrélations liant le volume de l'épiphyse aux poids somatique et encéphalique chez les rongeurs, les insectivores, les chiropteres, les prosimiens et les simiens. Mammalia40, 327–337 (1976).
Lynch, G. R., Sullivan, J. K., Gendler, S. L.: Temperature regulation in the mouse,Peromyscus leucopus: Effects of various photoperiods, pinealectomy and melatonin administration. Int. J. Biometeorology24, 49–55 (1980).
McNab, B. K.: The metabolism of fossorial rodents: a study of convergence. Ecology47, 712–733 (1966).
McNab, B. K.: The influence of fat deposits on the basal rate of metabolism in desert homoiotherms. Comp. Biochem. Physiol.26, 337–343 (1968).
Pevet, P., Ariëns Kappers, J., Nevo, E.: The pineal gland of the Mole-rat (Spalax ehrenbergi, Nehring). Cell Tiss. Res.174, 1–24 (1976).
Pevet, P., Yadav, M.: The pineal gland of equatorial mammals. I. The pinealocytes of the Malaysian Rat (Rattus sabanus). Cell Tiss. Res.210, 417–433 (1980).
Quay, W. B.: Volumetric and cytologic variation in the pineal body ofPeromyscus leucopus (Rodentia) with respect to sex, captivity and daylength. J. Morphol.98, 471–495 (1956).
Quay, W. B.: Physiological significance of the pineal during adaptation to shifts in photoperiod. Physiol. Behav.5, 353–360 (1970).
Quay, W. B.: Pineal homeostatic regulation of shifts in the circadian activity rhythm during maturation and aging. Trans. New York Acad. Sci. Ser. II,34, 239–254 (1972).
Quay, W. B.: Quantitative morphology and environmental responses of the pineal gland in the Collared Lemming (Dicrostonyx groenlandicus). Am. J. Anat.153, 545–562 (1978).
Quay, W. B.: Greater pineal volume at higher latitudes in Rodentia: Exponential relationship and its biological interpretation. Gen. Comp. Endocrinol.41, 340–348 (1980 a).
Quay, W. B.: Pineal volume and latitudinal and chronobiological characteristics: Comparisons of five mammalian Orders. Am. Zoologist20, 898 (1980 b).
Quay, W. B.: Unusual pineal size and morphology in the Orkney Vole (Microtus arvalis orcadensis), J. Mammal, (in press).
Ralph, C. L., Firth, B. T., Gern, W. A., Owens, D. W.: The pineal complex and thermoregulation. Biol. Rev.54, 41–72 (1979).
Reiter, R. J.: Circannual reproductive rhythms in mammals related to photoperiod and pineal function: A review. Chronobiologia1, 365–395 (1974).
Reiter, R. J.: The pineal and its hormones in the control of reproduction in mammals. Endocrine Reviews1, 109–131 (1980).
Starck, D.: Beobachtungen anHeterocephalus glaber Rüppell 1842 (Rodentia, Bathyergidae) in der Provinz Harar. Zschr. für Säugetierkunde22, 50–56 (1957).
Stumpf, W. E., Hellreich, M. A., Aumüller, G., Lamb, J. C. IV, Sar, M.: The collicular recess organ: Evidence for structural and secretory specialization of the ventricular lining in the collicular recess. Cell Tiss. Res.184, 29–44 (1977).
Vollrath, L.: Comparative morphology of the vertebrate pineal complex. Prog. Brain Res.52, 25–37 (1979).
Wood, A. E.: A revised classification of the rodents. J. Mammal.36, 165 to 187 (1955).
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Quay, W.B. Pineal atrophy and other neuroendocrine and circumventricular features of the naked mole-rat,heterocephalusglaber (Rüppell), a fossorial, equatorial rodent. J. Neural Transmission 52, 107–115 (1981). https://doi.org/10.1007/BF01253102
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DOI: https://doi.org/10.1007/BF01253102