Section Days abstract book 2010.indd - RUB Research School ...

LS_18
LASTING EFFECTS OF A SINGLE MK801-INDUCED
PSYCHOTIC EVENT ON HIPPOCAMPAL SYNAPTIC
PLASTICITY IN VIVO
1,2,3 Valentina Wiescholleck, 1,2 Denise Manahan-Vaughan
1 Learning and Memory Research, Department of Neurophysiology; 2 International
graduate school of Neuroscience; 3 Research School; Ruhr-Universität Bochum, 44780
Bochum, Germany
e-mail: valentina.kopp@rub.de
|The acute application of NMDA receptor antagonists, such as MK801 (dizolcilpine), have
been shown to induce psychotic symptoms in humans and to give rise to an acute and shortlasting
behavioral state in rats, which mirrors many symptoms of schizophrenia. It has
therefore been adopted as an animal model of psychosis. In the present study we examined
changes in LTP after a single MK801 injection over a prolonged period. In control animals,
high frequency stimulation (HFS) elicited robust LTP that persisted for over 24h and was not
different from pretreatment LTP at any investigated point of time. One week after MK801
treatment, LTP was severely impaired, exhibiting a smaller induction magnitude and enduring
for ca. 2h. In the second and third weeks after MK801, application of HFS resulted in LTP
that was not significantly different compared to pretreatment LTP. Interestingly, by 4.5 weeks
after MK801-treatment, HFS elicited LTP that was again significantly impaired compared to
pretreatment LTP. These data suggest that a single MK801 injection elicits functional changes
that result in an initial LTP impairment, followed by transient recovery and subsequently by a
new reduction in the ability to express synaptic plasticity. These changes may reflect
cognitive disturbances that occur in episodes of psychosis.