Effects of Platform Deprivation

The number of studies performed with the platform technique has increased over the last decennium and it is likely that the simplicity and cheapness of the technique together with an ignorance for the older debates in the literature are the reasons for this increase. An overview of publications from 1990 till 2000 shows 42 papers in which REM sleep deprivation in rats was performed by the platform technique. A wide area of deprivation effects was studied, ranging from cognitive, behavioural, physiological, biochemical and cellular studies. Brock et al., Porkka-Heiskanen et al. and Basheer et al. examined deprivationinduced norepinephrine changes in the brain. These groups found changes, but all in different brain areas. Studies on deprivation-induced serotonin levels also revealed diverging facts. Brock et al. found decreased values in both frontal and parietal cortex, while Youngblood et al. found increased rates of serotonergic metabolism in the brain. Different results were also obtained by one research group. Brock et al. found a decreased dopaminergic activity in the frontal cortex as a result of deprivation, while a second study showed an unchanged dopamine activity in both frontal and parietal cortices. Contradictory results were also obtained by Mallick and Thakkar who examined REM sleep deprivation-induced acetylcholinesterase levels in the brain. A first study revealed an increase only in the medulla, while a second study showed an increase in the whole brain, with the exception of the cerebellum. Moreover, Camarini and Benedito found a decrease of acetylcholinesterase in the frontal cortex. Research about deprivation-induced vasoactive intestinal peptide changes in the brain showed an increased peptidereceptor density in both brainstem and forebrain structures and also a decrease of vasoactive intestinal peptide in cortex and pituitary. Cellular mechanisms such as calcium, glucose metabolic enzymes and membrane fluidity were investigated by Mallick and Thakkar. An increase in cholinesterase in the medulla was found in one study, while in another the cholinesterase was increased in the whole brain with the exception of the cerebellum. The Na-K ATPase activity and the membrane rigidity were increased. Total calcium was increased in the brainstem and decreased in the cerebellum and the cerebrum, free calcium was decreased, whereas bound calcium was diminished in the cerebrum and the cerebellum, but increased in the brainstem. Adrien’s group examined the consequences of REM sleep deprivation on neuronal activity and the effects of 5-HT reuptake blockers. Chronic treatment with zimeldine together with REM sleep deprivation induced a hyporeactivity of nucleus raphe dorsalis neurons to the inhibitory effect of citaprolam in non-deprived rats. This group is interested in the putative antidepressant effects of REM sleep deprivation and related work is performed by Vogel and Hagler. Velaszquez-Moctezuma et al. is interested in the role of REM sleep deprivation on sexual behaviour and described a major deterioration in masculine sexual behaviour; Carley et al. investigated REM sleep deprivation in relation to the cardiopulmonar system and sleep apneas. Deprivation of REM