Researchers at Harvard School of Medicine and the University at Buffalo have discovered a sleep-promoting circuit located deep in the primitive brainstem, only the second "sleep node" identified in the mammalian brain whose activity appears to be both necessary and sufficient to produce deep sleep. 

Writing in Nature Neuroscience, the study demonstrates that fully half of all of the brain's sleep-promoting activity originates from the parafacial zone (PZ) in the brainstem. The brainstem is a primordial part of the brain that regulates basic functions necessary for survival, such as breathing, blood pressure, heart rate and body temperature.

Even a single dose of  the commonly prescribed antidepressant SSRI (serotonin reuptake inhibitor) is enough to produce dramatic changes in the functional architecture of the human brain. Brain scans taken of people before and after an acute dose of SSRI reveal changes in connectivity within three hours, according to results in Current Biology.

Tropical rabbitfish have devastated algal forests in the eastern Mediterranean Sea and pose a major threat to the entire Mediterranean basin if their distribution continues to expand as the climate warms, according to a new study
in the Journal of Ecology.

The members of the team surveyed more than 1000 kilometers of coastline in Turkey and Greece, where two species of rabbitfish have become dominant since they moved into the region via the Suez Canal.