The claim states that unilateral 6-OHDA lesions in Parkinson models cause ipsilateral rotations due to dopaminergic imbalance. This is a foundational, axiomatic mechanism taught in neurobiology and utilized across hundreds of animal model studies to test dopaminergic integrity (often assessed via amphetamine or apomorphine rotation tests). Because it is a textbook neuroscientific fact and the premise underlying the experimental designs of multiple retrieved papers (e.g., papers [2], [11]), no single citation is uniquely required to establish it; it functions as common knowledge within the field.