Rejuvenation of plasticity in the brain: opening the critical period.
Level 5 - mechanism / opinion, no new human data
Narrative review of mechanistic hypotheses without original human trial or observational data.
PubMed 30286407 · doi:10.1016/j.conb.2018.09.003
What was done
This narrative review examines mechanistic hypotheses surrounding the regulation and reactivation of postnatal critical periods for sensory plasticity. The authors evaluate evidence concerning two neuromodulatory mechanisms—cortical disinhibition and thalamic adenosine signaling—and discuss theoretical approaches to reopen critical-period plasticity in the adult auditory cortex.
What was found
The abstract reports no empirical numbers or quantitative findings. It presents the hypothesis that cortical disinhibition and thalamic adenosine co-regulate auditory critical periods and that targeting these pathways alongside attention-related neuromodulation may restore juvenile-like plasticity in adult circuits.
Why it matters
Identifying pathways that regulate critical periods provides theoretical targets for enhancing neurorehabilitation, sensory recovery, and adult learning.
Limits
The review presents mechanistic models without providing quantitative data, effect sizes, or a systematic search methodology in the abstract. The underlying mechanisms rely heavily on animal neurobiology with uncertain direct translation to human adults.
Cited by
- supports Until roughly age 25, passive experience alone shapes the brain, whereas after age 25 neuroplasticity requires active attention and a marked shift in the neurochemical environment.