Methods and compositions for improved cognition

1. A method of treating cognitive decline in an individual having a neurodegenerative disease or traumatic brain injury (TBI), comprising administering systemically to the individual an effective amount of a recombinant polypeptide comprising the amino acid sequence having at least 95% identity to the sequence of amino acids 34-979 of SEQ ID NO:1, with the proviso that the polypeptide is not a FGF fusion protein.

2. The method of claim 1 , wherein the individual's neurodegenerative disease is Alzheimer's disease, Parkinson's disease, frontotemporal dementia, mild cognitive impairment, or Lewy body dementia.

3. The method of claim 1 , wherein the amino acid sequence is at least 99% identical to amino acids 34-979 of SEQ ID NO:1.

4. The method of claim 1 , wherein the amino acid sequence comprises amino acids 34-979 of SEQ ID NO:1.

5. The method of claim 1 , comprising:

determining cognitive function in the subject before administration of the polypeptide,

determining cognitive function in the subject following systemic administration of the polypeptide, and

comparing the cognitive function in the subject before administration of the klotho to the cognitive function of the subject following administration of the polypeptide.

6. The method of claim 1 , wherein the polypeptide is administered to the subject intravenously.

7. The method of claim 2 , wherein the individual's neurodegenerative disease is Alzheimer's Disease.

8. The method of claim 2 , wherein the individual's neurodegenerative disease is Parkinson's Disease.

9. The method of claim 2 , wherein the individual's neurodegenerative disease is frontotemporal dementia.

10. The method of claim 2 , wherein the individual's neurodegenerative disease is mild cognitive impairment.

11. The method of claim 2 , wherein the individual's neurodegenerative disease is Lewy body dementia.

12. The method of claim 1 , wherein the individual has traumatic brain injury.