An electrophysiological study of D2 dopaminergic actions in normal human retina: a tool in Parkinson's disease.
A peculiar deficit of electrophysiological retinal responses to pattern reversal grating stimuli has been reported in Parkinson's disease (PD) patients. A similar abnormality has been reproduced by means of non-selective dopaminergic antagonists in normal humans. Aim of this study was to verify, by means of a selective D2 antagonist (sulpiride) administered to normal subjects, whether a D2 blockade affects the visual electrophysiological performances with the same trend as observed in PD patients. Patterns electroretinogram (PERG) responses to 1 cycle per degree (c/d) of spatial frequency at 1 (transient) and 7.5 (steady state) Hz of temporal modulation of a square-wave grating pattern reversal have been recorded in 19 healthy volunteers before and after the administration of 100 mg i.m. of sulpiride. The data are consistent for the following conclusion: a selective D2 antagonist reduces steady state and delays transient retinal responses as expected for a PD mimicking agent.
Stanzione
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P
Clinica Neurologica II Università di Roma Tor Vergata, Italy.
Traversa
R
R
Pierantozzi
M
M
Semprini
R
R
Marciani
M G
MG
Bernardi
G
G
D000328:Adult; D065127:Dopamine D2 Receptor Antagonists; D006801:Humans; D010300:Parkinson Disease / Q000503:physiopathology*; D017448:Receptors, Dopamine D2 / Q000502:physiology*; D012016:Reference Values; D012160:Retina / Q000187:drug effects / Q000502:physiology*; D013469:Sulpiride / Q000494:pharmacology*; D014786:Vision Disorders / Q000209:etiology*
D065127:Dopamine D2 Receptor Antagonists; D017448:Receptors, Dopamine D2; D013469:Sulpiride