Synaptic Reorganization of the Perisomatic Inhibitory Network in Hippocampi of Temporal Lobe Epileptic Patients

Figure 4

Light micrographs show the distribution of CB1-immunoreactive elements in the human control (a, c) and epileptic (b–d) dentate gyrus. (a) Dense CB1-immunopositive meshwork was present around the dentate granule cells and in the stratum moleculare (s. m.). The hilus (H) contained less CB1-positive terminals. Arrow points to a CB1-positive interneuron. (b) In epileptic patients with hippocampal sclerosis the density of CB1-positive fibers has been increased in the stratum moleculare and granulosum. Note the dispersion of granule cells. Arrows point to CB1-positive interneurons. (c) CB1-immunostained terminals were present in the hilus, in homogenous distribution. Arrow points to a CB1-positive interneuron. (d) In the hilus of the epileptic hippocampus more CB1-positive terminals were present; they often formed dense network around surviving mossy cells or interneurons (arrowheads).

(a) Control

(b) Epileptic

(c) Control

(d) Epileptic