Spindle neuron
A large neuron tapered at both ends that is only found in humans and great apes and so is thought to be a relatively recent evolutionary addition to the nervous system.
Spindle neurons are confined to the anterior cingulate cortex, a region of the brain that plays a role in emotion, decision-making, and autonomic functions of the brain such as the regulation of the heart rate and blood pressure.
Spindle neurons are typically lost in the course of Alzheimer disease.