Figure 1.
The hippocampal mossy fiber bouton. (A) Low power electron microscopic image of two adjacent MFBs (MFB1, MFB2) taken from an adult rat. Both MFBs outlined in yellow terminate on different dendritic segments, but preferentially on spiny excrescences (blue contours). AZs are given in red and astrocytic profiles (dark diaminobenzidine reaction product) in green. Scale bar: 2.5 μm. (B) Glial coverage of an individual MFB showing the distribution of astrocytic processes (highlighted in green) as revealed by glutamine synthetase pre-embedding immunohistochemistry. The surface of an individual MFB (in light yellow), its postsynaptic spiny excrescences (ex; in light blue) was surrounded by several astrocytic processes (in green). Note, that the fine glial processes do not reach the AZs (in red) and the synaptic cleft. The mitochondria (mi) within the MFB are highlighted in white. Scale bar: 1 μm.
