Rapid resolution of first episodes of mania: sleep related?

BACKGROUND: While sleep deprivation has been observed to precipitate mania, the relationship between sleep and resolution of mania is less well understood. We observed a rapid reversal of manic symptoms in several patients hospitalized for mania who slept many hours on Night 1 of hospitalization. We therefore undertook to study this relationship more systematically. METHOD: Charts for all patients admitted with a diagnosis of bipolar disorder, manic within a 2-year period were retrospectively reviewed. Patients were assigned to a group called "rapid responders" if improvement in symptoms, as described in progress notes, was moderate by Day 2 of hospitalization. Patients were "nonrapid responders" if improvement in symptoms was minimal or mild by Day 2. Sleep records, medications, and demographic data were obtained by researchers blind to the patients' response status on Day 2 of hospitalization. RESULTS: Compared with the 27 patients who did not have a rapid response, the 7 rapid responders were significantly more likely to (1) be in a first manic episode, (2) have a stressor associated with the onset of mania, (3) sleep more hours the first night of hospitalization, and (4) spend fewer days in the hospital. CONCLUSION: The possibility is raised that sleep restoration might induce a rapid antimanic response in patients experiencing their first episode of mania. The clinical implications of a rapid reversal of mania--including a reduction in number of hospital days--are discussed.

Neurophysiology of limbic system pathways in the rat: projections from the amygdala to the entorhinal cortex.

We studied the responses of rat entorhinal neurons to electrical stimulation of the amygdala. Four main results were obtained: (1) excitatory postsynaptic potentials were recorded in entorhinal neurons in response to electrical stimulation of the amygdala. Cells in layers II, III and V of the entorhinal cortex were responsive. (2) Excitatory responses were followed by inhibitory postsynaptic potentials. (3) Frequency potentiation of both excitatory and inhibitory responses was observed when 10/s stimulation was used. (4) Three amygdala neurons were antidromically activated by entorhinal stimulation; and two layer II entorhinal cells that were excited by amygdala stimulation were also antidromically activated by dentate gyrus stimulation. These results provide evidence for a monosynaptic, excitatory projection from the amygdala to the entorhinal cortex. In addition, the data indicate that amygdala neurons are only one synapse removed from the excitation of dentate gyrus granule cells.