358
Brain Research, 105 (1976) 358-361 © Elsevier ScientificPublishing Company, Amsterdam - Printed in The Netherlands
Unilateral electrolytic lesions of the substantia nigra cause contralateral circling in rats
WILLIAM J. SCHWARTZ, RUFUS H. GUNN, FRANK R. SHARP AND EDWARD V. EVARTS Laboratory of Neurophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, Md. 20014 (U.S.A.)
(Accepted December 15th, 1975)
Certain experimental manipulations of the dopaminergic nigrostriatal system result in characteristic head-to-tail circling behavior in a number of laboratory animals. Thus, in rats, unilateral electrolytic lesions of the caudatoputamen 9 or of the ascending nigrostriatal pathway at the level of the lateral hypothalamus a,24 and unilateral 6-hydroxydopamine (6-OHDA) lesions of the pathway 26 or of the substantia nigra22, ~4 cause the animals to rotate towards the side of the lesion (ipsilaterally). On the basis of this and further evidence gleaned from electrical stimulation in ratsa, 4 and pharmacological manipulations in rats2, 24-27, mice 2a and cats 7, a hypothesis has been advanced that rotation is secondary to an imbalance of the two dopaminergic nigrostriatal systems and that its direction is away from the side with greater dopaminergic activity. In this note, we call attention to the behavioral effects of unilateral electrolytic lesions of the substantia nigra in rats and to their implications for this hypothesis. A total of 29 Sprague-Dawley rats (weighing approximately 150 g each) were anesthetized with ethyl ether and underwent either electrolytic or 6-OHDA lesions stereotaxically placed 17 in the nigrostriatal system. Unilateral electrolytic lesions were made in 17 animals; l0 in the right lateral hypothalamic area (A 3700-3900; L 1500; H 2500) in the region of the ascending dopaminergic nigrostriatal pathway16, 2a, and 7 in the right substantia nigra (A 1600-2400; L 1500; H 2500-3000). In these animals, 2 mA of current was passed for 30 sec via stainless steel electrodes insulated to within 0.5 mm of their tips. Unilateral 6-OHDA lesions were made in 8 animals; 4 in the right lateral hypothalamic area (A 3000), and 4 in the right substantia nigra (A 2000). The 6-OHDA solution was made by dissolving 1 mg 6-hydroxydopamine dihydrobromide (base) and 0.1 mg ascorbic acid in 0.5 ml sterile saline; each rat was injected with 8 #g 6-OHDA in 4 #l solution over 4 min via a Hamilton syringe. All animals were then observed for spontaneous rotatory behavior (while in their cages or on a flat surface) immediately after lesioning and for up to 72 h postoperatively. They were then killed with an overdose of sodium pentobarbital and lesion sites confirmed histologically.
359
,VT
)
..°.°
A 2420
I?IU~ J~:,'~ MB
A 1950 SNR
RN
A 1610 IP
CC
Fig. 1. Extent of a lesion which resulted in contralateral rotation. Levels are according to the atlas of K6nig and KlippelxT. CC, ~us cerebri; FOR, reticular formation; IP, interpeduncular nucleus; LM, medial lemniscus; MB, peduncle of the mammillary body; RN, red nucleus; SNC, substantia nigra, pars compacta; SNR, substantia nigra, pars reticulata; VT, ventral nucleus of thalamus.
360 Those rats with either electrolytic or 6-OHDA lesions interrupting the nigrostriatal pathway as it ascends through the lateral hypothalamus, and those with 6O H D A lesions of the substantia nigra, all spontaneously circled ipsilaterally postoperatively. 6-OHDA-lesioned animals rotated in a tight, compulsive, head-to-tail manner during recovery from anesthesia and for 5-10 min afterwards. Tail pinching after this time could provoke rotation for several hours more. Electrolytically lesioned animals showed similar behavior, but they would circle spontaneously for hours rather than for minutes. On the other hand, electrolytic lesions of the substantia nigra resulted in a similar spontaneous, compulsive rotation, but towards the side opposite the lesion (contralaterally). Effective lesions (Fig. 1) were of the medial substantia nigra, including parts of both pars compacta and pars reticulata. Nigral-lesioned animals would spontaneously circle for hours to days and could be provoked to do so for as long as 72 h postoperatively. Larger lesions at the level of the substantia nigra, involving parts of medial lemniscus, mammillary peduncle, and midbrain reticular formation, but largely sparing the nigra itself, were ineffective in eliciting rotation in 4 animals. A recent abstract from another laboratory has also noted contralateral rotation after unilateral electrolytic lesions of the substantia nigra in ratslL 6-OHDA is believed to cause a selective destruction of catecholamine-containing neurons 18, whereas electrolytic lesions would be expected to result in a nonspecific destruction of both catecholaminergic and non-catecholaminergic neurons. Therefore, we infer from the above behavioral evidence that there exists at least one other output from the rat substantia nigra besides the dopaminergic nigrostriatal one. Furthermore, this output is non-catecholaminergic, and it has an effect on rotatory behavior opposite to that of the dopaminergic system. Anatomically, other nigral efferents have already been suggested, and two possible candidates include a nigrothalamic pathway in ratslO, 1~,14, cats1, ~0 and monkeys 5, and 6 a suspected non-dopaminergic nigrostriatal pathway in rats12,13, 21 and cats ~1. Alternatively, it is possible that our electrolytic lesions have merely destroyed fibers of passage in or near the substrantia nigra, and that these fibers are the ones responsible for our results. Summing up, unilateral 6-OHDA lesions of the substantia nigra in rats result in spontaneous, compulsive ipsilateral circling, but similarly placed electrolytic lesions of the structure cause contralateral circling. We infer that there exist at least two efferents from the rat substantia nigra; one, the dopaminergic nigrostriatal pathway, and the other a non-catecholaminergic output. Both these pathways are important in determining the direction of head-to-tail circling after acute nigral lesions.
Efferent connections of the substantia nigra in the cat, Exp. Neurol., 11 0965) 474-482. 2 ANDI~N, N. E., DAHLSTRbM,A., FUXE,K., AND LARSSON, K., Functional role of the nigro-neostriatal dopamine neurons, Acta pharmacoL (Kbh.), 24 (1966) 263-274. 3 ARBUTHNOTT,G. W., AND CROW, T. J., Relation of contraversive turning to unilateral release of dopamine from the nigro-striatal pathway in rats, Exp. NeuroL, 30 (1971) 484-491. 4 ARBUTHNOTT,G. W., AND UNGERSTEDT, U., Turning behavior induced by electrical stimulation of the nigro-neostriatal system of the rat, Exp. Neurol., 47 (1975) 162-172. 1 AFIFI, A., AND KAELBER, W. W.,
361 5 CARPENTER,M. B., ANDPETER,P., Nigrostriatal and nigrothalamic fibers in the rhesus monkey, J. cutup. Neurol., 144 0972) 93-116. 6 CARPENTER, M. B., AND STROMINGER,N. L., Efferent fibers of the subthalamic nucleus in the monkey. A comparison of the efferent projections of the subthalamic nucleus, substantia nigra, and globus pallidus, Amer. J. Anat., 121 (1967) 41-72. 7 COOLS,A. R., Chemical and electrical stimulation of the caudate nucleus in freely moving cats: the role of dopamine, Brain Research, 58 (1973) 437-451. 8 CORRODI,H., FUXE,K., AND LIDBRINK,P., Interaction between cholinergic and catecholaminergic neurons in rat brain, Brain Research, 43 (1972) 397-416. 9 DANKOVA,J., BOUCHER,R., AND POIRIER,L. J., Role of the strio-pallidal system and motor cortex in induced circus movements in rats and cats, Exp. Neurol., 47 (1975) 135-149. 10 FAULL,R. L. H., AND CARMAN,J. B., Ascending projections of the substantia nigra in the rat, J. cutup. Neurol., 132 (1968) 73-92. l l FELTZ, P., AND DECHA~n'LAIN,J., Persistence of caudate unitary responses to nigral stimulation after destruction and functional impairment of the striatal dopaminergic terminals, Brain Research, 43 (1972) 595-600. 12 FImGER,H. C., PUDPJTZ,R. E., MCGEER,P. L., AND MCGEER, E. G., ATonal transport in nigrostriatal and nigrothalamic neurons: effects of medial forebrain bundle lesions and 6-hydroxydopamine, J. Neurochem., 19 (1972) 1697-1708. 13 HATTORI,T., FIBIGER,H. C., MCGEER,P. L., AND MALER,L., Analysis of the fine structure of the dopaminergic nigrostriatal projection by electron microscopic autoradioautography, Exp. Neurol., 41 (1973) 599-611. 14 HEDREEN,J. C., Separate demonstration of dopaminergic and non-dopaminergic projections of substantia nigra in rat, Anat. Rec., 169 (1971) 338. 15 HODGE,G. K., ANDBUTCHER,L. L., Behavioral effects following discrete lesions of pars compacta of the substantia nigra in rats. In Soc. Neurosci., 5th Annu. Meet., New York City, 1975, p. 196, abstract. 16 JACOBOWITZ,n . M., AND PALKOVITS,i . , Topographic atlas of catecholamine and acetylcholinesterase-containing neurons in the rat brain. 1. Forebrain (telencephalon, diencephalon), J. cutup. NeuroL, 157 (1974) 13-28. 17 K~NIG, J. F. R., AND KLIPPEL, R. A., The Rat Brain: A Stereotaxic Atlas of the Forebrain and Lower Parts of the Brain Stem, Williams and Wilkins, Baltimore, Md., 1963. 18 KOSTRZEWA,R. i . , . AND JACOBOWlTZ,D. M., Pharmacological actions of 6-hydroxydopamine, Pharmacol. Rev., 26 (!974) 199-288. 19 MALER,L., FIBIGER,H. C., AND MCGEER, P. L., Demonstration of the nigrostriatal projection by silver staining after nigral injections of 6-hydroxydopatnine, Exp. Neurol., 40 (1973) 505-515. 20 RINVIK, E., Demonstration of nigrothalamic connections in the cat by retrograde axonal transport of horseradish peroxidase, Brain Research, 90 (1975) 313-318. 21 SINGH,V. K., FImGER,H. C., AND MCGEER,P. L., Effects of 6-hydroxydopamine on the nature of proteins undergoing axoplasmic transport in nigro-neostriatal neurons, J. Neurochem., 23 (1974) 601-604. 22 UNGERSTEDT,O., 6-Hydroxydopamine induced degeneration of central monoamine neurons, Europ. J. PharmacoL, 5 (1968) 107-110. 23 UNGERSTEDT,U., StereotaXic mapping of the monoamine pathways in the rat brain, Aetaphysiok scand., 82, Suppl. 367 (1971) 1-48. 24 UNGERSTEDT,O., Striatal dopamine release after amphetamine or nerve degeneration revealed by rotational behavior, Acta physiol, scand., 82, Suppl. 367 (1971)49-68. 25 UNGERSTEDT,O., Postsynaptic supersensitivity after 6-hydroxydopamine induced degeneration of the nigrostriatal system, Actaphysiol. scand., 82, Suppl. 367 (1971) 69-93. 26 UNGERSTEDT,O., AND ARBUTHNOTT,G. W., Quantitative recording of rotational behavior in rats after 6-hydroxydopamine lesions of the nigrostriatal dopamine system, Brain Research, 24 (1970) 485-493. 27 UNGERSTEDT,O., BUTCHER,L. L., BUTCHER,S. G., ANDEN,"N. E., AND FUXE,K., Direct chemical stimulation of dopaminergic mechanisms in the neostriatum of the rat, Brain Research, 14 (1969) 461-471. 28 VON VOIGTLANDER,P. F., AND MOORE,K. E., Turning behavior of mice with unilateral 6-hydroxydopamine lesions in the striatum: effects of apomorphine, L-DOPA, amantadine, amphetamine, and other psychomotor stimulants, Neuropharmacology, 12 (1973) 451-462.
Brain Research, 105 (1976) 358-361 © Elsevier ScientificPublishing Company, Amsterdam - Printed in The Netherlands
Unilateral electrolytic lesions of the substantia nigra cause contralateral circling in rats
WILLIAM J. SCHWARTZ, RUFUS H. GUNN, FRANK R. SHARP AND EDWARD V. EVARTS Laboratory of Neurophysiology, National Institute of Mental Health, National Institutes of Health, Bethesda, Md. 20014 (U.S.A.)
(Accepted December 15th, 1975)
Certain experimental manipulations of the dopaminergic nigrostriatal system result in characteristic head-to-tail circling behavior in a number of laboratory animals. Thus, in rats, unilateral electrolytic lesions of the caudatoputamen 9 or of the ascending nigrostriatal pathway at the level of the lateral hypothalamus a,24 and unilateral 6-hydroxydopamine (6-OHDA) lesions of the pathway 26 or of the substantia nigra22, ~4 cause the animals to rotate towards the side of the lesion (ipsilaterally). On the basis of this and further evidence gleaned from electrical stimulation in ratsa, 4 and pharmacological manipulations in rats2, 24-27, mice 2a and cats 7, a hypothesis has been advanced that rotation is secondary to an imbalance of the two dopaminergic nigrostriatal systems and that its direction is away from the side with greater dopaminergic activity. In this note, we call attention to the behavioral effects of unilateral electrolytic lesions of the substantia nigra in rats and to their implications for this hypothesis. A total of 29 Sprague-Dawley rats (weighing approximately 150 g each) were anesthetized with ethyl ether and underwent either electrolytic or 6-OHDA lesions stereotaxically placed 17 in the nigrostriatal system. Unilateral electrolytic lesions were made in 17 animals; l0 in the right lateral hypothalamic area (A 3700-3900; L 1500; H 2500) in the region of the ascending dopaminergic nigrostriatal pathway16, 2a, and 7 in the right substantia nigra (A 1600-2400; L 1500; H 2500-3000). In these animals, 2 mA of current was passed for 30 sec via stainless steel electrodes insulated to within 0.5 mm of their tips. Unilateral 6-OHDA lesions were made in 8 animals; 4 in the right lateral hypothalamic area (A 3000), and 4 in the right substantia nigra (A 2000). The 6-OHDA solution was made by dissolving 1 mg 6-hydroxydopamine dihydrobromide (base) and 0.1 mg ascorbic acid in 0.5 ml sterile saline; each rat was injected with 8 #g 6-OHDA in 4 #l solution over 4 min via a Hamilton syringe. All animals were then observed for spontaneous rotatory behavior (while in their cages or on a flat surface) immediately after lesioning and for up to 72 h postoperatively. They were then killed with an overdose of sodium pentobarbital and lesion sites confirmed histologically.
359
,VT
)
..°.°
A 2420
I?IU~ J~:,'~ MB
A 1950 SNR
RN
A 1610 IP
CC
Fig. 1. Extent of a lesion which resulted in contralateral rotation. Levels are according to the atlas of K6nig and KlippelxT. CC, ~us cerebri; FOR, reticular formation; IP, interpeduncular nucleus; LM, medial lemniscus; MB, peduncle of the mammillary body; RN, red nucleus; SNC, substantia nigra, pars compacta; SNR, substantia nigra, pars reticulata; VT, ventral nucleus of thalamus.
360 Those rats with either electrolytic or 6-OHDA lesions interrupting the nigrostriatal pathway as it ascends through the lateral hypothalamus, and those with 6O H D A lesions of the substantia nigra, all spontaneously circled ipsilaterally postoperatively. 6-OHDA-lesioned animals rotated in a tight, compulsive, head-to-tail manner during recovery from anesthesia and for 5-10 min afterwards. Tail pinching after this time could provoke rotation for several hours more. Electrolytically lesioned animals showed similar behavior, but they would circle spontaneously for hours rather than for minutes. On the other hand, electrolytic lesions of the substantia nigra resulted in a similar spontaneous, compulsive rotation, but towards the side opposite the lesion (contralaterally). Effective lesions (Fig. 1) were of the medial substantia nigra, including parts of both pars compacta and pars reticulata. Nigral-lesioned animals would spontaneously circle for hours to days and could be provoked to do so for as long as 72 h postoperatively. Larger lesions at the level of the substantia nigra, involving parts of medial lemniscus, mammillary peduncle, and midbrain reticular formation, but largely sparing the nigra itself, were ineffective in eliciting rotation in 4 animals. A recent abstract from another laboratory has also noted contralateral rotation after unilateral electrolytic lesions of the substantia nigra in ratslL 6-OHDA is believed to cause a selective destruction of catecholamine-containing neurons 18, whereas electrolytic lesions would be expected to result in a nonspecific destruction of both catecholaminergic and non-catecholaminergic neurons. Therefore, we infer from the above behavioral evidence that there exists at least one other output from the rat substantia nigra besides the dopaminergic nigrostriatal one. Furthermore, this output is non-catecholaminergic, and it has an effect on rotatory behavior opposite to that of the dopaminergic system. Anatomically, other nigral efferents have already been suggested, and two possible candidates include a nigrothalamic pathway in ratslO, 1~,14, cats1, ~0 and monkeys 5, and 6 a suspected non-dopaminergic nigrostriatal pathway in rats12,13, 21 and cats ~1. Alternatively, it is possible that our electrolytic lesions have merely destroyed fibers of passage in or near the substrantia nigra, and that these fibers are the ones responsible for our results. Summing up, unilateral 6-OHDA lesions of the substantia nigra in rats result in spontaneous, compulsive ipsilateral circling, but similarly placed electrolytic lesions of the structure cause contralateral circling. We infer that there exist at least two efferents from the rat substantia nigra; one, the dopaminergic nigrostriatal pathway, and the other a non-catecholaminergic output. Both these pathways are important in determining the direction of head-to-tail circling after acute nigral lesions.
Efferent connections of the substantia nigra in the cat, Exp. Neurol., 11 0965) 474-482. 2 ANDI~N, N. E., DAHLSTRbM,A., FUXE,K., AND LARSSON, K., Functional role of the nigro-neostriatal dopamine neurons, Acta pharmacoL (Kbh.), 24 (1966) 263-274. 3 ARBUTHNOTT,G. W., AND CROW, T. J., Relation of contraversive turning to unilateral release of dopamine from the nigro-striatal pathway in rats, Exp. NeuroL, 30 (1971) 484-491. 4 ARBUTHNOTT,G. W., AND UNGERSTEDT, U., Turning behavior induced by electrical stimulation of the nigro-neostriatal system of the rat, Exp. Neurol., 47 (1975) 162-172. 1 AFIFI, A., AND KAELBER, W. W.,
361 5 CARPENTER,M. B., ANDPETER,P., Nigrostriatal and nigrothalamic fibers in the rhesus monkey, J. cutup. Neurol., 144 0972) 93-116. 6 CARPENTER, M. B., AND STROMINGER,N. L., Efferent fibers of the subthalamic nucleus in the monkey. A comparison of the efferent projections of the subthalamic nucleus, substantia nigra, and globus pallidus, Amer. J. Anat., 121 (1967) 41-72. 7 COOLS,A. R., Chemical and electrical stimulation of the caudate nucleus in freely moving cats: the role of dopamine, Brain Research, 58 (1973) 437-451. 8 CORRODI,H., FUXE,K., AND LIDBRINK,P., Interaction between cholinergic and catecholaminergic neurons in rat brain, Brain Research, 43 (1972) 397-416. 9 DANKOVA,J., BOUCHER,R., AND POIRIER,L. J., Role of the strio-pallidal system and motor cortex in induced circus movements in rats and cats, Exp. Neurol., 47 (1975) 135-149. 10 FAULL,R. L. H., AND CARMAN,J. B., Ascending projections of the substantia nigra in the rat, J. cutup. Neurol., 132 (1968) 73-92. l l FELTZ, P., AND DECHA~n'LAIN,J., Persistence of caudate unitary responses to nigral stimulation after destruction and functional impairment of the striatal dopaminergic terminals, Brain Research, 43 (1972) 595-600. 12 FImGER,H. C., PUDPJTZ,R. E., MCGEER,P. L., AND MCGEER, E. G., ATonal transport in nigrostriatal and nigrothalamic neurons: effects of medial forebrain bundle lesions and 6-hydroxydopamine, J. Neurochem., 19 (1972) 1697-1708. 13 HATTORI,T., FIBIGER,H. C., MCGEER,P. L., AND MALER,L., Analysis of the fine structure of the dopaminergic nigrostriatal projection by electron microscopic autoradioautography, Exp. Neurol., 41 (1973) 599-611. 14 HEDREEN,J. C., Separate demonstration of dopaminergic and non-dopaminergic projections of substantia nigra in rat, Anat. Rec., 169 (1971) 338. 15 HODGE,G. K., ANDBUTCHER,L. L., Behavioral effects following discrete lesions of pars compacta of the substantia nigra in rats. In Soc. Neurosci., 5th Annu. Meet., New York City, 1975, p. 196, abstract. 16 JACOBOWITZ,n . M., AND PALKOVITS,i . , Topographic atlas of catecholamine and acetylcholinesterase-containing neurons in the rat brain. 1. Forebrain (telencephalon, diencephalon), J. cutup. NeuroL, 157 (1974) 13-28. 17 K~NIG, J. F. R., AND KLIPPEL, R. A., The Rat Brain: A Stereotaxic Atlas of the Forebrain and Lower Parts of the Brain Stem, Williams and Wilkins, Baltimore, Md., 1963. 18 KOSTRZEWA,R. i . , . AND JACOBOWlTZ,D. M., Pharmacological actions of 6-hydroxydopamine, Pharmacol. Rev., 26 (!974) 199-288. 19 MALER,L., FIBIGER,H. C., AND MCGEER, P. L., Demonstration of the nigrostriatal projection by silver staining after nigral injections of 6-hydroxydopatnine, Exp. Neurol., 40 (1973) 505-515. 20 RINVIK, E., Demonstration of nigrothalamic connections in the cat by retrograde axonal transport of horseradish peroxidase, Brain Research, 90 (1975) 313-318. 21 SINGH,V. K., FImGER,H. C., AND MCGEER,P. L., Effects of 6-hydroxydopamine on the nature of proteins undergoing axoplasmic transport in nigro-neostriatal neurons, J. Neurochem., 23 (1974) 601-604. 22 UNGERSTEDT,O., 6-Hydroxydopamine induced degeneration of central monoamine neurons, Europ. J. PharmacoL, 5 (1968) 107-110. 23 UNGERSTEDT,U., StereotaXic mapping of the monoamine pathways in the rat brain, Aetaphysiok scand., 82, Suppl. 367 (1971) 1-48. 24 UNGERSTEDT,O., Striatal dopamine release after amphetamine or nerve degeneration revealed by rotational behavior, Acta physiol, scand., 82, Suppl. 367 (1971)49-68. 25 UNGERSTEDT,O., Postsynaptic supersensitivity after 6-hydroxydopamine induced degeneration of the nigrostriatal system, Actaphysiol. scand., 82, Suppl. 367 (1971) 69-93. 26 UNGERSTEDT,O., AND ARBUTHNOTT,G. W., Quantitative recording of rotational behavior in rats after 6-hydroxydopamine lesions of the nigrostriatal dopamine system, Brain Research, 24 (1970) 485-493. 27 UNGERSTEDT,O., BUTCHER,L. L., BUTCHER,S. G., ANDEN,"N. E., AND FUXE,K., Direct chemical stimulation of dopaminergic mechanisms in the neostriatum of the rat, Brain Research, 14 (1969) 461-471. 28 VON VOIGTLANDER,P. F., AND MOORE,K. E., Turning behavior of mice with unilateral 6-hydroxydopamine lesions in the striatum: effects of apomorphine, L-DOPA, amantadine, amphetamine, and other psychomotor stimulants, Neuropharmacology, 12 (1973) 451-462.
