Fig. 1: Optogenetic stimulation of GABAergic cells in ZI-induced IPSCs in RE neurons.
From: Incerto-thalamic modulation of fear via GABA and dopamine
A vGAT-CRE mice were injected with Cre-dependent ChannelRhodopsin2 (AAV5-EF1α-DIO-ChR2-mCherry) at −1.5 mm posterior to bregma and the optic fiber was placed above the RE at −0.38 mm posterior to bregma. B Representative image of the ZI targeted with intracranial infusions of ChR2-expressing mCherry viruses (right) and representative image of the mCherry expressing GABAergic projection fibers in the RE with cannula placed above the region (indicated by arrows) (left). C Illustration of experimental configuration for optic stimulation and in vitro patch-clamp recordings from RE neurons (left). Optic stimulation (473 nm blue light, 1.6 mW/mm2) was directed at ChR2-expressing GABAergic projections in RE. Sample traces of superimposed light-evoked currents recorded at the indicated holding potentials shown to the left of each trace (right). The evoked inhibitory post-synaptic currents (IPSCs) had a reversal potential of −65 mV, close to chloride equilibrium potential. D Bath application of 20 µM AMPA receptor antagonist DNQX had no effect on light-evoked IPSCs while 5 µM of GABA receptor antagonist gabazine completely blocked light-evoked IPSCs. Scale bars: 100 µm.
