A researcher studies a genetic mutation in mice that alters synaptic connections in the retina. In wild-type (normal) mice, each cone cell synapses with a single, dedicated bipolar neurone. In mutant mice, several adjacent cone cells converge and synapse onto a single, shared bipolar neurone, as shown in the diagram below.
Which of the following correctly predicts and explains the physiological effect of this mutation on the performance of these cone cells in mutant mice compared to wild-type mice?
Increased visual acuity under high light intensities because multiple cone cells stimulate the same bipolar neurone to resolve finer details.
Increased sensitivity under low light intensities because neurotransmitter released from multiple cone cells can combine by spatial summation to reach the threshold of the bipolar neurone.
Decreased sensitivity under low light intensities because neurotransmitter from multiple cone cells cancels out due to temporal summation in the bipolar neurone.
Decreased visual acuity under high light intensities because there is no retinal convergence, preventing the brain from localizing the source of light.