Fig. 4.

DREADD expression. Alterations typical for the intrahippocampal kainic acid mouse model can be observed in the ipsilateral hippocampus: loss of pyramidal neurons in CA1–CA3 regions (left and right CA1 pyramidal cell layers are indicated with a black arrow in A), hippocampal shrinkage (sclerosis), and dentate granule cell dispersion (reorganization and enlargement of the granule cell layer, thickness of left and right granule cell layers are indicated with a black line in A). The HA tag which is coupled to the hM4Di DREADD receptor is mainly localized in the sclerotic hippocampus (fibers and cell bodies, A, B) but also in the contralateral hippocampus (fibers, A and C). Some expression is observed in strongly connected regions such as retrosplenial cortex (fibers, D), reticular and midline thalamic nuclei (fibers), and alongside the injection tract (cortex, fibers, and cell bodies). Some cell bodies are indicated with an arrow. Scale bar = 1 mm