Non-invasive brain stimulation protects cognitive impairment in i.c.v.STZ injected rats: role of adult neurogenesis

In Alzheimer’s like dementia, neurodegeneration and synaptic dysfunction is known to the critical player in explaining the cognitive impairment. Adult neurogenesis, normally a chronic and quite process is explained to have potential in the field of Alzheimer’s therapy. Previous research on the non-invasive brain stimulation showed that controlling pattern of stimulation externally we can regulate/ entrain neuronal activity, possibly altering the structural changes in the circuit level. However, literature investigating if non-invasive brain stimulation could hold any potential to initiate process of adult neurogenesis are scarce. In the present study, with the use of behavioural, microscopic and biochemical tools we found that extremely low frequency magnetic field at an intensity of 17.96µT with sinusoidal wave of 50Hz for 2hr daily for a period of two week in streptozotocin induced animal model of sporadic Alzheimer’s disease can cause improvement in spatial and reference memory, influencing their swimming strategy in water maze. Which is caused by stimulation in immature neural pluripotent stem cells, with additional redox balance and mitigation of glial aggravation in brain areas like olfactory bulb, prefrontal cortex and hippocampus. These changes were accompanied by neuroprotection as observed in the granular layer of dentate gyrus. Taken together, present study explains plausible mechanism of action on protection of neurodegeneration in Alzheimer’s disease through non-invasive brain stimulation.