Final answer:
The incorrect statement about central sensitization is 'b. Decreased spontaneous activity (ectopic and ephaptic signals)', as central sensitization actually results in increased, not decreased, spontaneous neuronal activity. Increased activity and excitability in the nervous system are often associated with neurotransmitters like glutamate and substance P.
Step-by-step explanation:
Central sensitization involves several changes in the central nervous system that lead to an increased response to pain. The statement 'Central sensitization includes all of the following EXCEPT: a. caused by glutamate and substance P b. Decreased spontaneous activity (ectopic and ephaptic signals) c. Increased responsiveness to afferent inputs d. Increased receptive field size (collateral sprouting and arborization) e. Intense and persistent signals' identifies key aspects except for 'b. Decreased spontaneous activity (ectopic and ephaptic signals)', which is not a characteristic of central sensitization. Instead, central sensitization is associated with increased spontaneous activity. Central sensitization is characterized by increased neuronal activity, which can be due to heightened signal transduction from peripheral nerves into the central nervous system.
This heightened neural activity is caused by neurotransmitters like glutamate and substance P, which lead to an amplified response to pain (increased responsiveness to afferent inputs) and can cause changes such as increased receptive field size. This is frequently observed in pathological conditions such as epilepsy, wherein there is an increase in glutamatergic synaptic strength, and in addiction, where glutamatergic pathways become dysregulated. Overall, the persistent excitatory neurotransmission involving glutamate and other signaling molecules contributes to the pathogenesis of several neurological disorders, manifesting as hyperalgesia or allodynia.