Is there a non-synaptic component in the K+-stimulated release of GABA in the developing rat cortex?

Postnatal development of the K+-stimulated release of [3H]GABA in rat cortex slices was compared to the density of Gray type 2 synapses (which correlate with GABAergic synapses in rat cortex). The [3H]GABA release system develops earlier than the inhibitory synapses which suggests that, at least in the young cortical tissue, a large part of the release mechanism is associated with other than synaptic structures.