The blues and rhythm.

Most organisms, including humans, show daily rhythms in many aspects of physiology and behavior, and abnormalities in the rhythms are potential risk factors for various diseases. Mood disorders such as depression are no exception. Accumulating evidence suggests strong associations between circadian disturbances and the development of depression.

Stepwise synaptic plasticity events drive the early phase of memory consolidation.

Memories are initially encoded in the hippocampus but subsequently consolidated to the cortex. Although synaptic plasticity is key to these processes, its precise spatiotemporal profile remains poorly understood. Using optogenetics to selectively erase long-term potentiation (LTP) within a defined temporal window, we found that distinct phases of synaptic plasticity play differential roles.

Two Functionally Distinct Serotonergic Projections into Hippocampus.

Hippocampus receives dense serotonergic input specifically from raphe nuclei. However, what information is carried by this input and its impact on behavior has not been fully elucidated. Here we used two-photon imaging of activity of hippocampal median raphe projection fibers in behaving male and female mice and identified two distinct populations: one linked to reward delivery and the other to locomotion.