Breaking the Brain Clock (IMAGE) University of Pennsylvania School of Medicine Caption This image shows synaptic degeneration and impaired functional connectivity in cortex of Bmal1 knockout. Electron micrographs show presynaptic terminals (Sy) in 6-month-old wild-type mouse (A) and Bmal1 knockout (B and C) retrosplenial cortex. In Bmal1 knockout cortex, synaptic terminals are swollen and relatively devoid of synaptic vesicles, while the presynaptic and postsynaptic membranes, synaptic cleft, and dendritic spine [D] have normal morphology. Bmal1 knockout mice showed both normal and abnormal terminals. Activated astrocytes and numerous organelle-rich astrocytic processes were seen throughout the Bmal1 KO cortical tissue. Scale bars: 500 nm. Credit Erik Musiek, M.D., Ph.D., <i>Journal of Clinical Investigation</i> Usage Restrictions PLease use credit line. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.