GENE-EXPRESSION OF THE NICOTINIC ACETYLCHOLINE-RECEPTOR ALPHA-4 SUBUNIT IN THE FRONTAL-CORTEX IN PARKINSONS-DISEASE PATIENTS

Cognitive impairment in Parkinson's disease is accompanied by a marked decrease of cerebrocortical nicotinic receptors. To study the putativ e site of impaired receptor synthesis, frontal cortices of Parkinson p atients with cognitive dysfunction have been screened for the expressi on of the nicotinic receptor alpha 4 subunit gene. Quantitative assess ment of alpha 4 mRNA-expressing neurons did not show significant diffe rences between patients and controls. Therefore, decreased nicotinic r eceptor sites cannot be attributed to alterations at the transcription al level of the alpha 4 gene. Alternative causes have to be searched f or at the translational and/or postranslational level.