By detecting the associated mRNA, UCP2, UCP4, and UCP5 were shown to reside in neurons throughout the human central nervous system. These proteins play key roles in neuronal function. While many study findings remain controversial, several findings are widely accepted.
For example, UCPs alter the free calcium concentrations in the neuron. Mitochondria are a major site of calcium storage in neurons, and the storage capacity increases with potential across mitochondrial membranes. Therefore, when the uncoupling proteins reduce potential across these membranes, calcium ions are released to the surrounding environment in the neuron. Due to the high concentrations of mitochondria near axon terminals, this implies UCPs play a role in regulating calcium concentrations in this region. Considering calcium ions play a large role in neurotransmission, scientists predict that these UCPs directly affect neurotransmission.
As discussed above, neurons in the hippocampus experience increased concentrations of ATP in the presence of these uncoupling proteins. This leads scientists to hypothesize that UCPs improve synaptic plasticity and transmission.