As old age sets in and your memory starts to fail, can the problem be reversed? Two recent studies have presented initial evidence that it may be possible.
In a mouse study, UK researchers at Cambridge University and colleagues in Italy, Japan, Canada, Netherlands and Singapore, managed to reverse memory loss using chondroitin-6-sulphate – a substance previously shown to increase lifespan in the nematode worm Caenorhabditis elegans.
The scientists, whose study was published in Nature.com, reported that ‘age-related reduction of chondroitin-6-sulphates (C6S) leads to PNNs (perineuronal nets: chondroitin sulphate proteoglycan- containing structures on the neuronal surface implicated in control of neuroplasticity and memory) becoming more inhibitory.
‘We investigated whether manipulation of the chondroitin sulphate (CS) composition of the PNNs could restore neuroplasticity and alleviate memory deficits in aged mice.’
They found ‘overall the results of this study… indicate treatments targeting PNNs have the potential to ameliorate memory deficits associated with ageing’.
Now in a second US study at Boston University, also reported in Nature.com, researchers improved memory function in 60 adults aged between 65-88 using electrical stimulation via a wearable cap.
Participants given 20 minutes of electrical trans-cranial stimulation on 4 consecutive days exhibited improvement in both ‘auditory- verbal working’ memory and ‘long-term’ memory for at least 1 month. Moreover the researchers could focus the stimulation to affect different types of memory.
Co-author Dr Robert Reinhart told medicalnewstoday.com: ‘We developed two brain stimulation protocols — one for selectively improving short-term memory via low-frequency parietal stimulation, and another for selectively improving long-term memory via high-frequency prefrontal stimulation.’
In the study, modulation of synchronous low-frequency, but not high-frequency, activity in parietal cortex preferentially improved working memory on day 3 and day 4 and 1month after intervention, whereas modulation of synchronous high-frequency, but not low- frequency, activity in prefrontal cortex preferentially improved long-term memory on days 2–4 and 1 month after intervention.
‘The rate of memory improvements over 4 days predicted the size of memory benefits 1 month later. Individuals with lower baseline cognitive function experienced larger, more enduring memory improvements.’
The researchers concluded: ‘Our findings demonstrate the plasticity of the ageing brain can be selectively and sustainably exploited using repetitive and highly focalised neuromodulation grounded in spatio- spectral parameters of memory- specific cortical circuitry.’
However the improvement was only tested over one month, so the researchers have called for further investigation into whether similar treatments might have a long-term benefit.
