Hippocampal Theta Input to the Amygdala Shapes Feedforward Inhibition to Gate Heterosynaptic Plasticity.
Bottom Line: These effects are mediated by GABAB receptors and change in the Cl(-) driving force.Hence, feedforward inhibition, known to enforce temporal fidelity of excitatory inputs, dominates hippocampus-amygdala interactions to gate heterosynaptic plasticity.VIDEO ABSTRACT.
Affiliation: MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3TH, UK.Show MeSH
Mentions: We then sought to understand the influence of a theta frequency input from vCA1 pyramidal cells on the firing of BA neurons. To this aim, we transfected pyramidal cells of vCA1 with the ultrafast (E123T/T159C) Channelrhodopsin-2 (ChR2) (Figures 2A and S2), which more efficiently evokes action potentials at high frequency stimulation compared to the common H134R variant (Berndt et al., 2011). Three to four weeks after viral injection, ChR2+ axons densely innervated the BA and BM, together with the external and intermediate capsules surrounding the BLA, whereas only sparse fibers were observed in the LA (Figure 2B). This pattern of innervation was consistent with previous tracing studies in rodents (Kishi et al., 2006; Müller et al., 2012).
Affiliation: MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3TH, UK.