What condition results from the autoimmune attack on ACh receptors?

Myasthenia gravis is indeed the condition characterized by an autoimmune attack on acetylcholine (ACh) receptors. In this disorder, the immune system produces antibodies that mistakenly target and damage the nicotinic ACh receptors at the neuromuscular junction. This impairment in receptor function leads to muscle weakness and fatigue, as the ability of acetylcholine to stimulate muscle contraction is diminished.

In contrast, Alzheimer's disease primarily involves the degeneration of cholinergic neurons in the brain, leading to cognitive decline and memory loss, rather than an autoimmune response targeting receptors. Parkinson's disease is associated with the loss of dopaminergic neurons in the substantia nigra, which affects motor control but does not involve an autoimmune attack on ACh receptors. Similarly, Huntington's disease results from genetic mutations leading to neuronal degeneration, particularly in the basal ganglia, without an autoimmune mechanism affecting ACh receptors.

Thus, myasthenia gravis is uniquely defined by this autoimmune interaction with ACh receptors, leading to the hallmark symptoms of muscle weakness and fatigue.