Loss of the PTEN tumour suppressor has recently been identified as a persuasive target for increasing regenerative capacities of neurons affected in degenerative conditions or following injury to the nervous system. In mice, for example, loss of PTEN expression has been shown to promote axonal elongation and increases survival in cell bodies and axon terminals of degenerating motor neurons, as well as promoting regenerative growth of axonal processes following injury to the CNS. Here, we present a technique to specifically tune PTEN function in mammalian tissue with high specificity and temporal control. In this technique, destabilising domains derived from E. coli dihydrofolate reductase (DHFR*) or from the FK506-binding protein 12 (FKBP*) are fused to proteins of interests, causing their efficient degradation. Presence of DHFR* or FKBP* specific ligands – Trimethoprim (TMP) and Shield, respectively – stabilise tagged proteins and confer biological activity. We combined in utero electroporation (under isoflurane in O2 anaesthesia) of DHFR* or FKBP* tagged proteins into the cortex of mouse embryos with subsequent stabilisation by systemic application of TMP or Shield. We established methods to deliver the synthetic ligands, analysing their abilities to cross the blood-brain barrier and tested the functional efficacies of stabilized proteins. We successfully generated active Cre-DHFR* and FKBP*-PTEN protein expression systems, which, in combination with floxed-PTEN mouse alleles, enables precise control of PTEN-loss and re-installing PTEN. In this way, PTEN levels and activity can be managed precisely within specific experimental paradigms. We believe such information will prove essential for understanding the degree in which transient PTEN inhibition can indeed be seen as an amenable target for reinstalling growth in degenerative conditions or following injury to the CNS.