1 Certain parts of the brain shrink, especially the prefrontal cortex (an area at the front of the frontal lobe) and the hippocampus. 2  Both areas are important to learning, memory, planning, and other complex mental activities.
Some big, fluffy dog breeds are the chow chow, the samoyed, the standard poodle, the old English sheepdog and the keeshond. The abundant, fluffy coats of these dogs require constant care. Keep Learning.
General Appearance Noble and impressive: a large, but not a giant breed. An athletic and substantial dog, of solemn but kindly appearance. The Tibetan Mastiff stands well up on the pasterns, with strong, tight, cat feet, giving an alert appearance. The body is slightly longer than tall. The hallmarks of the breed are the head and the tail.