There are, of course, other sequences of evolution which can be regarded as progressive trends in complexity such as the increase in size of the brain of Homo over the last two million years. (religion-online.org)
The small numbers and large sizes of brain cells in sea slugs make the animals ideal for brain research. (scientificamerican.com)
The brain regions most affected are those involved in reward, emotion and learning — although it isn't clear yet whether the smaller than average size of these brain areas could be a cause or effect of addiction. (newscientist.com)