Skip to main content
. Author manuscript; available in PMC: 2010 Aug 2.
Published in final edited form as: Eur J Neurosci. 2008 Nov;28(10):2028–2040. doi: 10.1111/j.1460-9568.2008.06479.x

Fig. 6.

Fig. 6

Cocaine reduces evoked and spontaneous GABA inhibitory synaptic transmission to VTA DA neurons in vitro. (A) This graph shows the time-course for the effects of cocaine (at the IC50 for inhibition of VTA GABA neuron sodium current) on VTA DA IPSCs. The inset shows representative superimposed traces of IPSCs (each trace is an average of 12 sweeps collected at 0.1 Hz) obtained in a DA neuron before (lighter trace) and 10 to 12 min after cocaine (darker trace). (B) Cocaine significantly decreased DA IPSCs at 7, 13 and 50 μm. (C) The inset shows superimposed representative traces of IPSCs (each is an average of 12 sweeps collected at 0.1 Hz) before (lighter trace) and 10 to 12 min after cocaine (darker trace). Cocaine increased the paired-pulse ratio of DA neuron IPSCs. (D) These insets show the effects of cocaine on spontaneous IPSCs (sIPSCs) recorded in a representative DA neuron. Cocaine (13 μm) significantly reduced the frequency, but not amplitude, of DA neuron sIPSCs. (E) These insets show the effects of cocaine on mIPSCs recorded in a representative DA neuron after treatment with TTX. Cocaine (13 μm) had no effect on frequency or amplitude of TTX-insensitive miniature IPSCs. *P < 0.05, **P < 0.01 and ***P < 0.001.