Brain prosthetic restores learning capability in rats

September, 2011

Effective patterns of neural activity replayed via an artificial device inserted in the hippocampus restores lost learning capability and even improves learning in normal rats.

In the experiment, rats learned which lever to press to receive water, where the correct lever depended on which lever they had pressed previously (the levers were retractable; there was a variable delay between the first and second presentation of the levers). Microelectrodes in the rats’ brains provided data that enabled researchers to work out the firing patterns of neurons in CA1 that resulted from particular firing patterns in CA3 (previous research had established that long-term memory involves CA3 outputs being received in CA1).

Normal neural communication between these two subregions of the hippocampus was then chemically inhibited. While the rats still remembered the general rule, and still remembered that pressing the levers would gain them water, they could only remember which lever they had pressed for 5-10 seconds.

An artificial hippocampal system that could reproduce effective firing patterns (established in earlier training) was then implanted in the rats’ brains and long-term memory function was restored. Furthermore, when the ‘memory prosthetic’ was implanted in animals whose hippocampus was functioning normally, their memory improved.

The findings open up amazing possibilities for ameliorating brain damage. There is of course the greatly limiting factor that effective memory traces (spatiotemporal firing patterns) need to be recorded for each activity. This will be particularly problematic for individuals with significant damage. Perhaps one day we will all ‘record’ ourselves as a matter of course, in the same way that we might put by blood or genetic material ‘in case’! Still, it’s an exciting development.

The next step will be to repeat these results in monkeys.

Reference: 

Recent posts at Mynd

A study involving 97 healthy older adults (65-89) has found that those with the “Alzheimer’s gene” (APOe4) who didn’t...

An Indian study involving 648 dementia patients, of whom 391 were bilingual, has found that, overall, bilingual patients developed dementia 4.5...

A study, involving 371 patients with mild cognitive impairment...

A study involving 206 spousal and adult children caregivers of dementia sufferers (mostly Alzheimer’s) has found that about 84% of...

A study involving 254 people with dementia living at home has found that 99% of people with dementia and 97% of their caregivers had one or more...

A new U.S. study suggests that Alzheimer's disease and other dementias are markedly under-reported on death certificates and medical records....

It’s often argued that telling people that they carry genes increasing their risk of Alzheimer’s will simply upset them to no purpose...

11 new genetic susceptibility factors for Alzheimer’s identified

The largest international study ever conducted on Alzheimer's...

Understanding a protein's role in familial Alzheimer's...

A brain imaging study of 162 healthy babies (2-25 months) has found that those who carried the ApoE4...

A gene linked to Alzheimer's has been linked to brain changes in childhood. This gene, SORL1, has two connections to Alzheimer’s: it...

Analysis of data from 237 patients with mild cognitive impairment...

Two studies indicate that young people carrying the “Alzheimer’s gene” (ApoE4...

Analysis of data from more than 8,000 people, most of them older than 60, has revealed that, among the 5,000 people initially tested cognitively...

Analysis of 700 subjects from the Alzheimer's Disease Neuroimaging Initiative has revealed a genetic mutation (rs4728029) that’s associated...

Analysis of brain scans and cognitive scores of 64 older adults from the NIA's Baltimore Longitudinal Study of Aging (average age 76) has found...