Alzheimer’s and Parkinson’s diseases are neurodegenerative diseases which cannot be cured so far. In both diseases, a GABAergic-glutaminergic neurotransmitter imbalance might occur. Neural networks are suggested for Parkinson’s disease in the extrapyramidal system and for Alzheimer’s disease in the hippocampus and the temporal cortex. Combined GABAA agonists and NMDA antagonists might have therapeutic and maybe prophylactic properties in Alzheimer’s and Parkinson’s disease. It is important to examine the neural networks in the brain areas involved in both diseases. This would offer the possibility to try an early beginning pharmacotherapy of these, up to now, incurable diseases.