DISCUSSION. WIN 55,212-2 had been shown to disrupt Pre Pulse Inhibition (PPI) in rat- a measure of sensory motor gating ( Schneider & Koch, 2002) . However the effect of WIN 55,212-2 on auditory gating has not been examined before.
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ABOLITION OF SENSORY GATING BY THE CANNABINOID WIN55, 212-2 IN THE RAT HIPPOCAMPUS
Dissanayake WDN1, Zachariou M2, Marsden CA1 and Mason R1
School of Biomedical Sciences1, School of Mathematical sciences2, University of Nottingham Medical School, QMC, UK.
FIG 2: Effects of WIN 55,212-2 on gating compared with the effects of PCP
FIG 1: Hippocampal auditory-evoked LFP responses
T/C = 20 ± 8%
Basal (PCP control)
T/C = 25 ± 3%
LFP2 Averaged over 128 trials
WIN 1.2mg/kg i.p
PCP 1mg/Kg i.p
T/C = 81 ± 3%
T/C = 114 ± 21%
(A) Representative recording of auditory-evoked responses illustrating local field potentials from dentate gyrus (LFP1) and CA3 (LFP2).
(B) Averaged local field potentials recorded from CA3 for 128 stimulus presentation trials demonstrated a reduction in test (T) response amplitude compared to conditioning (C) response amplitude;
CS = Conditioning stimulus, TS = Test stimulus.
Averaged LFPs and peri-event LFP rasters recorded from CA3 in gating rats; basal recording compared with effect of WIN 55,212-2 and PCP 45 minutes after administration of each drug. Both averaged LFPS and rasters demonstrated a significant drug induced disruption of gating in CA3 with a higher T/C ratio seen after WIN.55,212-2. (
N40 responses )
FIG 4: Effects of (A) WIN 55,212-2 and (B) PCP on conditioning response (Camp) and test response (Tamp) amplitudes compared with the T/C ratios 15 and 45mins after drug administration
FIG 3:Effects of WIN 55,212-2 on Non gating rats compared with the effects of PCP
Basal (PCP control)
T/C = 87±8%
Basal (WIN control)
T/C = 97 ± 9%
WIN 1.2mg/kg i.p
PCP 1mg/kg i.p
T/C = 93 ± 7%
T/C = 94 ± 6%
A There was a significant increase in the Tamp (p<0.05) accompanied with a significant increase in the T/C ratio 45mins after administration of WIN. There was no significant change in Camp.
B There was a significant increase in the Tamp accompanied with a significant increase in the T/C ratio both 15 (p<0.01) and 45mins (p<0.01) after administration of PCP. There was no significant change in Camp.
Averaged LFPs and peri-event LFP rasters recorded from CA3 in non-gating rats; basal recording compared with effect of WIN 55,212-2 and PCP, 45 minutes after administration of each drug. Both averaged LFPS and rasters showed no significant drug induced changes in T/C ratios.
WDN Dissanayake was supported by the government of Sri Lanka and the University of Nottingham
International Office and M Zachariou by the Institute of Neuroscience University of Nottingham.
Harvey Wiggins and team at Plexon Inc USA.
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