Apoorva Bhandari1, Jennifer I Lissemore2, Tarek K Rajji3, Benoit H Mulsant4, Robin F H Cash5, Yoshihiro Noda6, Reza Zomorrodi7, Jordan F Karp8, Eric J Lenze9, Charles F Reynolds10, Zafiris J Daskalakis3, Daniel M Blumberger11. 1. Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada. 2. Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada. 3. Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada. 4. Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada. 5. Monash University, Alfred Psychiatry Research Centre, Melbourne, Australia. 6. Department of Psychiatry, Faculty of Medicine, Keio University, Japan. 7. Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada. 8. Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; VAPHS, Geriatric Research, Education, and Clinical Center, USA. 9. Healthy Mind Lab, Department of Psychiatry, Washington University School of Medicine, St Louis, MO, USA. 10. Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Department of Psychiatry, Pittsburgh, PA, USA. 11. Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, Toronto, Ontario, M6J 1H4, Canada; Department of Psychiatry, University of Toronto, Toronto, Ontario, M5T 1R8, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, M5T 1R8, Canada. Electronic address: daniel.blumberger@camh.ca.
Abstract
BACKGROUND: Studies using Transcranial Magnetic Stimulation (TMS), a non-invasive method of brain stimulation, have implicated impaired neuroplasticity in the pathophysiology of depression in younger adults. The role of neuroplasticity in late-life depression (LLD) has not yet been explored using TMS. OBJECTIVE: This study aimed at evaluating motor cortical neuroplasticity using paired associative stimulation (PAS). Single-pulse TMS was used to induce motor-evoked potentials (MEP) in the contralateral hand muscle before and after PAS. The potentiation of MEP amplitudes after PAS was used as an indirect index of associative plasticity and long-term potentiation (LTP) (i.e. PAS-LTP). RESULTS: 48 older adults with depression and 34 age-matched healthy controls (HC) were compared. PAS- LTP was successfully induced in 68.8% of older adults with depression and 47.1% of HC. At the group level, older adults with depression failed to show statistically significant induction of neuroplasticity, which was observed in HC. However, no significant differences were observed between the two groups for PAS-LTP. CONCLUSION: Our results suggest that associative plasticity does not differ substantially between older adults with depression and age-matched HC. Continued research is needed to more comprehensively understand the role of neuroplasticity in the pathophysiology of LLD.
BACKGROUND: Studies using Transcranial Magnetic Stimulation (TMS), a non-invasive method of brain stimulation, have implicated impaired neuroplasticity in the pathophysiology of depression in younger adults. The role of neuroplasticity in late-life depression (LLD) has not yet been explored using TMS. OBJECTIVE: This study aimed at evaluating motor cortical neuroplasticity using paired associative stimulation (PAS). Single-pulse TMS was used to induce motor-evoked potentials (MEP) in the contralateral hand muscle before and after PAS. The potentiation of MEP amplitudes after PAS was used as an indirect index of associative plasticity and long-term potentiation (LTP) (i.e. PAS-LTP). RESULTS: 48 older adults with depression and 34 age-matched healthy controls (HC) were compared. PAS- LTP was successfully induced in 68.8% of older adults with depression and 47.1% of HC. At the group level, older adults with depression failed to show statistically significant induction of neuroplasticity, which was observed in HC. However, no significant differences were observed between the two groups for PAS-LTP. CONCLUSION: Our results suggest that associative plasticity does not differ substantially between older adults with depression and age-matched HC. Continued research is needed to more comprehensively understand the role of neuroplasticity in the pathophysiology of LLD.
Authors: Robin F H Cash; Yoshihiro Noda; Reza Zomorrodi; Natasha Radhu; Faranak Farzan; Tarek K Rajji; Paul B Fitzgerald; Robert Chen; Zafiris J Daskalakis; Daniel M Blumberger Journal: Neuropsychopharmacology Date: 2016-07-27 Impact factor: 7.853
Authors: Michael J Player; Janet L Taylor; Cynthia Shannon Weickert; Angelo Alonzo; Perminder Sachdev; Donel Martin; Philip B Mitchell; Colleen K Loo Journal: Neuropsychopharmacology Date: 2013-05-16 Impact factor: 7.853
Authors: Warren D Taylor; Douglas R McQuoid; Martha E Payne; Anthony S Zannas; James R MacFall; David C Steffens Journal: Am J Geriatr Psychiatry Date: 2013-11-22 Impact factor: 4.105