Which event impairs function when certain toxins hyperstimulate synapses?

💡 Explanation

Excitotoxicity occurs because excessive synaptic stimulation triggers uncontrolled calcium influx through the NMDA receptors. This overwhelms the cell, disrupting its normal function and causing cell death, therefore excitotoxicity produces neurodegeneration, rather than simply vesicle depletion.

• If a mutation prevents rhodopsin from properly binding retinal in rod cells, which consequence follows regarding human vision in dim light?
• Why does skeletal muscle contraction velocity decrease as the load increases, despite ATP availability?
• If the ileum is surgically removed from a patient, which consequence follows regarding nutrient absorption?
• Why does accommodation lag (the delay in focusing on near objects) increase more sharply in individuals with early-stage presbyopia compared to age-matched individuals with normal vision?
• Why does skeletal muscle fiber contraction speed decrease during intense anaerobic exercise?
• If prolonged immobilization follows a femur fracture in a 70-year-old patient, which skeletal effect becomes most likely due to altered loading?