The effect of imipramine and lithium on "learned helplessness" and acetylcholinesterase in rat brain.

The effect of short- and long-term treatment with imipramine and lithium on shock stress-induced escape failures in a shuttlebox (the "learned helplessness" model of depression) was investigated in rats. Acetylcholinesterase (AChE) activity was measured in the frontal cortex, hippocampus and striatum after the shuttlebox test. Imipramine was found to normalize escape behavior, whereas lithium further aggravated escape behavior.

"Stat" measurements of L-lactate in whole blood and cerebrospinal fluid assessed.

A first-generation semi-automatic amperometric lactate analyzer (Yellow Springs Instrument Co.) was assessed for urgent ("stat"), rapid laboratory measurements in whole blood and cerebrospinal fluid. For whole blood, measured lactate concentration and hematocrit were linearly correlated.