Hypothalamic lesions

Moore, R.Y., and Heller, A. Monoamine levels and neuronal degeneration in rat brain following lateral hypothalamic lesions. J Pharmacol Exp Ther 156 12-22, 1967. 

Hart B.L. (1986). Medial preoptic-anterior hypothalamic lesions and sociosexual behavior of male goats. Physiol Behav 36, 301-305. 

Ranson, S. W. (1939). Somnolence caused by hypothalamic lesions in the monkey. 

Swett, C. P. 8r Hobson, J. A. (1968). The effects of posterior hypothalamic lesions on behavioral and electrographic manifestations of sleep and waking in cats. Arch. Ital. Biol. 106, 283-93. 

Weight gain can be caused by medical conditions (e.g., hypothyroidism, Cushing s syndrome, hypothalamic lesion) or genetic syndromes (e.g., Prader-Willi s syndrome), but these are unusual to rare causes of obesity. 

Malsbury, C. W., Kow, L. M. and Pfaff, D. W. (1977) Effects of medial hypothalamic lesions on the lordosis response and other behaviors in female golden hamsters. Physiol. Behav. 19, 223-37. 

Stephan FK 2002 The other circadian system. Food as a Zeitgeber. J Biol Rhythms 17 284-292 Stephan FK, Swann JM, Sisk CL 1979 Anticipation of 24-hr feeding schedules in rats with lesions of the suprachiasmatic nucleus. Behav Neural Biol 25 346—363 Stephan FK, Zucker I 1972 Circadian rhythms in drinking behavior and locomotor activity of rats are eliminated by hypothalamic lesions. Proc Natl Acad Sci USA 69 1583-1586 Stokkan KA, Yamazaki S, Tei H, Sakaki Y, Menaker M 2001 Entrainment of the circadian clock in the liver by feeding. Science 291 490-493... 

Numan M. and Corodimas K.P. (1985) The effects of paraventricular hypothalamic lesions on maternal behavior in rats. Physiol Behav 35 417-425. 

Feng PF, Bergmann BM, Rechtschaffen A. Sleep deprivation in rats with preop-tic/anterior hypothalamic lesions. Brain Res 1995 703 93-99. 

With the early application of stereotaxic surgery to neurological studies in experimental animals, Anand and Brobeck (1951) first reported that bilateral lesions of small nuclei in the hypothalamus could disrupt feeding behavior with medial hypothalamic lesions causing obesity and lateral lesions aphagia. In the latter syndrome, the lesioned animals would completely stop eating to the extent that if not maintained... 

Fig. 4. Proposed stages of recovery from the profound regulatory impairments induced by lateral hypothalamic lesions, based on Teitelbaum and Epstein (1972). A similar profile of recovery is seen from the impairments induced by selective bilateral lesions of forebrain dopamine systems (see text).

Teitelbaum P, Epstein AN (1962a) The lateral hypothalamic syndrome recovery of feeding and drinking after lateral hypothalamic lesions. Physiol Rev 69 74-90. 

Teitelbaum P, Stellar E (1954) Recovery from the failure to eat produced by hypothalamic lesions. Science 720 894-895. 

Zigmond MJ, Strieker EM (1973) Recovery of feeding and drinking by rats after intraventricular 6-hydroxydopamine or lateral hypothalamic lesions. Science 752 717-720. 

L)mch, J., Woinar, M., aitd Lang, C. (1997). Ventromedial hypothalamic lesions impair giucoregulation in response to endotoxin. Am. J. Pfiuipol. 272, K1525-R1531. 

Large concentrations of MSG administered by gavage or intravenous injection causes focal lesions in the hypothalamus of rodents and rabbits. These occur only hours after exposure. The mouse appears to be the most sensitive species affected. Neonatal animals are more sensitive to MSG neurotoxicity. Neuronal damage occurs in neonatal mice when plasma levels reach between 100 and dOOpmoldl. In adults, the plasma levels have to reach >630nmoldl before similar effects are noted. None of the primate studies were able to demonstrate hypothalamic lesions after exposure to MSG. 

The plasma levels of glutamate necessary to cause hypothalamic lesions in mice are never reached voluntarily in humans since the highest palatable dose is well below these concentrations. However, because of the animal studies, MSG is not recommended as an ingredient in baby formulas. 

Interpretation The serum cortisol concentration should increase to a peak value of >20pg/dL (550nmol/L). Serum GH concentration should rise to a peak value of >10 ng/mL. No response or inadequate responses may be due to pituitary hormone deficiency or to a hypothalamic lesion. 

Bestetti G, Rossi GL. 1980. Hypothalamic lesions in rats with longterm streptozotocin-induced diabetes mellitus. A semi-quantitative light and electron-microscopic study. Acta Neuropathol 52 119-127. 

Ventromedial hypothalamic lesions in rats suppress counterregulatory responses to hypoglycemia. J Clin Invest 93 1677-1682. 

Effects of hypothalamic lesion on pancreatic autonomic nerve activity in the rat. Brain Res 303 147-152. 

Hetherington AW, Ranson SW. Hypothalamic lesions and adiposity in the rat. Anat Rec 1940 78 149-172. Hill JO, Peters JC, Lin D, Yakubu F, Greene H, Swift L. Lipid accumulation and body fat distribution is... 

Fig. 8.5. Schematic summary of the effect of frequency of stimulation by GnRH on the secretion of the gonadotropic hormones LH (upper curve) and FSH (lower curve) in the rhesus monkey subjected to a hypothalamic lesion impairing its ability to generate GnRH (Thalabard et al, 1984, based on data from Pohletfll.,1983).

CNS. There have been studies in which Glu, often in the form of MSG, has been injected subcutaneously to neonatal mice or nonhuman primates and hypothalamic lesions noted. The lesions are mostly restricted to the circumventricular organs (those near the fourth ventricle), where the blood-brain barrier is significantly diminished. Additionally, when MSG is directly injected into the brains of laboratory animals, cellular necrosis is observed. When MSG is given in very high doses orally, however, the homeostatic processes in liver and other... 

Nagashima, K., Zabriskie, J.B., and Lyons, M.L 1992. Viras-induced obesity in mice Association with a hypothalamic lesion. J. Neuropathol. Exp. Neurol. 51, 101-109. 

Weingarten, H.P., Chang, P.K., and McDonald, T.J. 1985. Comparison of the metabolic and behavioral disturbances following paraventricular- and ventromedial-hypothalamic lesions. Brain Res. Bull. 14, 551-559. 

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