Multilamellar glial envelopes of synapses in the pontine nuclei of the cat

Multilamellar glial envelopes of synapses were observed in an ultrastructural study of the pontine nuclei of cats. They consist of several concentric coils, representing lamellar expansions of the astrocytic processes. Glial envelopes completely wrap various synapses (axodendritic, axospinous, glomerulus-like complexes, and contacts between vesicle containing profiles). The possibility that multilamellar glial envelopes might play a role in isolating and protecting diverse neurotransmitters in the pontine nuclei from loss and mingling is discussed.