Critical review on quantitative autoradiography of D1 and D2 dopaminergic receptors in the striatum of the mammalian brain: differential localization and plastic changes after pharmacological manipulation and dopaminergic input disruption.
Major technical progress in the development of computer-based image analysis systems has made possible the entry of autoradiographic and immunohistochemical techniques into a new era where quantification via densitometry and morphometry has become easily accessible. In this context, quantitative biochemical data can be adapted to anatomical and histological resolution. This adaptation is most efficient in the neuroscience fields because of the huge importance of cellular communication via neuronal networks in the nervous system. Therefore, any experimental approach to the brain which considers the brain as a 'black box' appears now as very crude. In fact, subtle heterogeneity in the distribution of biochemical markers can now be demonstrated, as illustrated here by the use of quantitative autoradiography of D1 and D2 dopaminergic receptors in the striatum of the mammalian brain. Also, local adaptive changes resulting from chronic blockade of the dopaminergic input can be detected after repeated treatments with dopaminergic antagonists selective for D1 or D2 receptors or with surgical lesioning of the dopaminergic nigrostriatal pathway. The resulting plastic changes are unevenly distributed throughout the striatal target organ and vary according to the mode of suppressing the dopaminergic flow: direct destruction of the dopaminergic pathway or selective pharmacological manipulation without physical elimination of the dopaminergic cells themselves. All these results are discussed and reviewed in light of the most recent reports in this field.
Feuerstein
C
C
Laboratoire de Physiologie section Neurophysiologie (LAPSEN), INSERM U 318, CHU de Grenoble, France.
Peretti-Renucci
R
R
Savasta
M
M
Scatton
B
B
Manier
M
M
Dubois
A
A
Thibault
J
J
Mons
N
N
Geffard
M
M
D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology; D001345:Autoradiography; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D003720:Densitometry; D006801:Humans; D006892:Hydroxydopamines / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D009473:Neuronal Plasticity / Q000187:drug effects; D016627:Oxidopamine; D011954:Receptors, Dopamine / Q000378:metabolism*; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2
D014150:Antipsychotic Agents; D006892:Hydroxydopamines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D016627:Oxidopamine