What removes glutamate after it is released, and why does the speed matter? · Grey Matter

There is no enzyme that destroys glutamate in the cleft; it is pumped away, mostly into astrocytes, whose transporters (GLT-1 carries about 90 % of the uptake in the adult forebrain) sit on the fine processes wrapped around synapses.

What removes glutamate after it is released, and why does the speed matter?

There is no enzyme that destroys glutamate in the cleft; it is pumped away, mostly into astrocytes, whose transporters (GLT-1 carries about 90 % of the uptake in the adult forebrain) sit on the fine processes wrapped around synapses. The astrocyte turns it into glutamine and returns that to neurons to be made into transmitter again. Fast clearance keeps each signal short and private to its synapse; when uptake slows, glutamate lingers, spills to neighbouring synapses and keeps receptors open, and altered astrocyte transporters are a common finding in epileptic tissue.