AFTER lesions have been made in one side of the nigro-striatal system, rats have been found to rotate when administered drugs which release dopamine (such as amphetamines) or activate dopamine receptors (such as apomorphine) in the corpus striatum (see for example refs 1 and 2). Because this circling effect is specific to the nigro-striatal system3 and because it has been established that rats consistently rotate contralateral to the more active striatum (for example ref. 4), the lesion–rotation paradigm is now commonly used as a model for the study of nigro-striatal function. Studies5,6 in our laboratory have shown that rats without lesions also rotate when administered doses of the same drugs larger than those administered to lesioned rats. As in lesioned rats, the directoin of rotation is consistent for normal rats; when tested on several different occasions with the same dose of the same drug, some rats consistently rotate to the right and others rotate to the left. This suggested that normal rats have an intrinsic asymmetry between left and right sides of the nigro-striatal system which is accentuated by drugs. This functional asymmetry corresponds to a chemical asymmetry7: the dopamine contents of normal left and right striata were found to differ by 10–15%. After administration of (+)-amphetamine, the dopamine contents of left and right striata were found to differ by 25%. Moreover, in response to (+)-amphetamine, rats consistently rotated contralateral to the side containing the most dopamine. This normal asymmetry suggests an inter-hemispheric mechanism that maintains or regulates the asymmetry. Mensah and Deadwyler8 demonstrated in rats a pathway between left and right caudate nuclei coursing through the ventral corpus callosum. It seemed plausible that this pathway may be part of the mechanism maintaining striatal asymmetry. We have now found that the striatal asymmetry is potentiated, both functionally and chemically, by callosal section.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Ungerstedt, U., Acta physiol. scand., Suppl. 367, 49 (1971).
Ungerstedt, U., Acta physiol. scand., Suppl. 367, 69 (1971).
Crow, T. J., Expl Neurol., 32, 247 (1971).
Arbuthnott, G. W., and Crow, T. J., Expl Neurol., 30, 484 (1971).
Jerussi, T. P., and Glick, S. D., Neuropharmacology, 13, 283 (1974).
Jerussi, T. P., and Glick, S. D., Psychopharmacologia, 40, 329 (1975).
Glick, S. D., Jerussi, T. Pl., Waters, D. H., and Green, J. P., Biochem. Pharmac., 23, 3223 (1974).
Mensah, P., and Deadwyler, S., J. Anat., 117, 281 (1974).
Glick, S. D., and Greenstein, S., Br. J. Pharmac., 49, 316 (1973).
Ungerstedt, U., and Arbuthnott, G. W., Brain Res., 24, 485 (1970).
Teitelbaum, H., J. comp. Physiol. Psychol., 76, 51 (1971).
Szilagyi, P. I. A., Green, J. P., Brown, O. M., and Margolis, S., J. Neurochem., 19, 2555 (1972).
Laverty, R., and Taylor, K. M., Analyt. Biochem., 22, 269 (1968).
Zimmerberg, B., Glick, S. D., and Jerussi, T. P., Science, 185, 623 (1974).
Hornykiewicz, O., in Recent Advances in Parkinson's Disease (edit. by McDowell, H., and Markham, C. H.), 33 (Davis, Philadelphia, 1971).
Glick, S. D., and Jerussi, T. P., J. Pharmac. exp. Ther., 188, 714 (1974).