Summary
The noradrenergic innervation of the medial preoptic area (MPO) and the hypothalamus is provided by mesencephalic neurons via the ventral noradrenergic tract. Fibers of these neurons emerge through the MPO. Bilateral microinjections of 6-OHDA into the ventral noradrenergic bundle (VNB) depletes large parts of the diencephalon of norepinephrine (NE) and dopamine (DA). Since the total hypothalamic DA content is of intrahypothalamic origin, 6-OHDA injection into the VNB does not reduce hypothalamic DA content. Similarly microinjections of 6-OHDA into the MPO reduces hypothalamic and preoptic NE content without altering NE concentrations in other diencephalic structures. Microinjections of 6-OHDA and of the carrier solution of 6-OHDA into the VNB or into the MPO of female rats with regular estrous cycles results in a slight disturbance of the cyclic activity for few days. Within 1–4 days normal cyclic activity is resumed. Preovulatory LH release is substantially reduced 8–12 days after injection of 6-OHDA into the VNB or into the MPO. On the basis of these and previous results it is concluded that the availability of NE in the MPO is an important factor in determining the hight of the preovulatory LH surge.
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References
Barry, J., Dubois, M.P., Poulain, P.: LRF-producing cells of the mammalian hypothalamus. Z. Zellforsch. 146, 351–366 (1973)
Björklund, A., Lindvall, O., Nobin, A.: Evidence of an incertohypothalamic dopamine neurone system in the rat. Brain Res. 89, 29–42 (1975)
Breese, G.R., Cooper, B.R.: Chemical lesioning: Catecholamine pathways, Methods Psychobiol. 3, 27–46 (1977)
Clemens, J.A., Tinsley, F.C., Fuller, R.W.: Evidence for a dopaminergic component in the series of neural events that lead to the pro-oestrus surge of LH. Acta Endocrinol. 85, 18–24 (1977)
Coppola, J.A.: Turnover of hypothalamic catecholamines during various states of gonadotrophin secretion. Neuroendocrinology 5, 75–80 (1969)
Coyle, J.T., Henry, D.: Catecholamines in fetal and newborn rat brain. J. Neurochem. 21, 61–67 (1973)
Fenske, M., Wuttke, W.: Effects of intraventricular 6-hydroxydopamine injections on serum prolactin and LH levels: Absence of stress-induced pituitary prolactin release. Brain Res. 104, 63–70 (1976)
Gugten, J.v.d., Palkovits, M., Wijnen, H.L.J.M., Versteeg, D.H.G.: Regional distribution of adrenaline in the brain. Brain Res. 107, 171–175 (1976)
Héry, M., Laplante, E., Kordon, C.: Participation of serotonin in the phasic release of LH. I. Evidence from pharmacological experiments. Endocrinology 99, 496–503 (1976)
Höhn, K.G., Witte, P., Wuttke, W.: Regional changes of catecholamine (CA)-turnover and CA-synthetizing enzymes in response to ovariectomy and estradiol. Acta Endocrinol. Suppl. 215, 103 (1978)
Höhn, K.G., Wuttke, W.: Changes in catecholamine turnover in the anterior part of mediobasal hypothalamus and the medial preoptic area in response to hyperprolactinemia in ovariectomized rats. Brain Res. 156, 241–252 (1978)
Kalra, P.S., Kalra, S.P., Krulich, L., Fawcett, C.P., McCann, S.K.: Involvement of norepinephrine in transmissionof the stimulatory influence of progesterone on gonadotropin release. Endocrinology 90, 1168–1176 (1972)
Kalra, P.S., McCann, S.M.: Effects of drugs modifying catecholamine synthesis on LH release induced by preoptic stimulation in the rat. Endocrinology 93, 356–362 (1973)
König, J.F.R., Klippel, R.A.: The rat brain. Huntington, New York: Krieger 1963
Kordon, C., Glowinsky, J.: Role of hypothalamic monoaminergic neurones in the gonadotropin release-regulating mechanisms. Neuropharmacology 11, 153–162 (1972)
Lowry, O.H., Rosenbrough, N.H., Farr, A.L., Randall, R.J.: Protein measurements with the folin phenol reagent. J. Biol. Chem. 193, 265–275 (1971)
Martinovic, J.V., McCann, S.M.: Effect of lesions in the ventral noradrenergic tract produced by microinjection of 6-hydroxydopamine on gonadotropin release in the rat. Endocrinology 100, 1206–1213 (1977)
Nicholson, G., Greeley, G., Humm, J., Youngblood, W., Kizer, J.S.: Lack of effect of noradrenergic denervation of the hypothalamus and medial preoptic area on the feedback regulation of gonadotropin secretion and the estrous cycle of the rat. Endocrinology 103, 559–566 (1978)
Niswender, G.D., Midgley, A.R., Jr., Monroe, S.E., Reichert, L.E., Jr.: Radioimmunoassay for rat luteinizing hormone with antiovine LH serum and ovine LH-131 I. Proc. Soc. Exp. Biol. Med. 128, 807–811 (1968)
Palkovits, M., Brownstein, M., Saavedra, J.M., Axelrod, J.: Norepinephrine and dopamine content of hypothalamic nuclei. Brain Res. 77, 137–149 (1974)
Palkovits, M., Fekete, M., Makara, G.B., Herman, J.P.: Total and partial hypothalamic deafferentations for topographical identification of catecholamine innervations of certain preoptic and hypothalamic nuclei. Brain Res. 127, 127–136 (1977)
Sawyer, C.H., Markee, J.E., Hollinshead, W.H.: Inhibition of ovulation in the rabbit by the noradrenergic blocking agent dibenamine. Endocrinology 40, 395–402 (1947)
Sawyer, C.H., Hilliard, J., Kanematsu, S., Scaramuzzi, R., Blake, C.A.: Effects of intraventricular infusions of norepinephrine and dopamine on LH release and ovulation in the rabbit. Neuroendocrinology 15, 328–337 (1974)
Stefano, F.J.E., Donoso, A.O.: Norepinephrine levels in the rat hypothalamus during the estrous cycle. Endocrinology 81, 1405–1411 (1967)
Ungerstedt, U.: Histochemical studies on the effect of intracerebral and intraventricular injections of 6-hydroxydopamine on monoamine neurons in the rat brain. In: 6-Hydroxydopamine and catecholamine neurons. (Eds.: Malmfors, T. and Thoenen, H.). pp. 101–127. Amsterdam: North Holland 1971a
Ungerstedt, U.: Use of intracerebral injections of 6-hydroxydopamine as a tool for morphological and functional studies on central catecholamine neurons. In: 6-Hydroxydopamine and catecholamine neurons. (Eds.: Malmfors, T. and Thoenen, H.). pp. 315–332. Amsterdam: North Holland 1971b
Uretsky, N.J., Iversen, L.L.: Effects of 6-Hydroxydopamine on noradrenaline-containing neurons in the rat brain. Nature 221, 557–559 (1969)
Uretsky, N.J., Iversen, L.L.: Effects of 6-Hydroxydopamine on catecholamine containing neurones in the rat brain. J. Neurochem. 17, 269–278 (1970)
Weindl, W., Sofroniew, M.: Neurohormones and circumventricular organs. In: Brain-Endocrine Interactions III. (Eds.: D.E. Scott, J. Koslowski and A. Weindl). pp. 117–137. Basel: Karger 1978
Weiner, R.I., Shryne, J.E., Gorski, R.A., Sawyer, C.H.: Changes in the catecholamine content of the rat hypothalamus following deafferentation. Endocrinology 90, 867–873 (1972)
Wuttke, W., Cassell, E.E., Meites, J.: Effects of ergocornine on serum prolactin and LH and on hypothalamic content of PIF and LRF. Endocrinology 88, 737–791 (1971)
Wuttke, W.: Neuroendocrine mechanisms in reproductive physiology. Rev. Physiol. Biochem. Pharmacol. 76, 59–101 (1976)
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Hancke, J.L., Wuttke, W. Effects of chemical lesion of the ventral noradrenergic bundle or of the medial preoptic area on preovulatory LH release in rats. Exp Brain Res 35, 127–134 (1979). https://doi.org/10.1007/BF00236789
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DOI: https://doi.org/10.1007/BF00236789