PS2107 The Plastic Brain.pptx

The Plastic Brain PS2107 Topics in Cognitive Neuroscience Dr Ioana Butnaru [email protected] Overview • Neuroplasticity – Structural neuroplasticity vs Functional neuroplasticity – Neuroplasticity mechanisms – Hebbian plasticity vs homeostatic plasticity – Spine pathologies – Research/therape...

The Plastic Brain PS2107 Topics in Cognitive Neuroscience Dr Ioana Butnaru [email protected] Overview • Neuroplasticity – Structural neuroplasticity vs Functional neuroplasticity – Neuroplasticity mechanisms – Hebbian plasticity vs homeostatic plasticity – Spine pathologies – Research/therapeutic overview “Use it or lose it” • First to demonstrate neuroplasticity – and critical periods David H. Hubel & Torsten N. Wiesel Nobel Prize for Physiology or Medicine in 1981 * the part of the visual cortex that is involved in processing visual information Striate cortex* in monkey Hubel, David H., and Torsten N. Wiesel. "Effects of monocular deprivation in kittens." Naunyn-Schmiedebergs Archiv for Experimentelle Pathologie und Pharmakologie 248 (1964): 492–7. London taxi drivers vs bus drivers • Black cab drivers have larger hippocampi when compared to bus drivers (Mcguire et al., 2006) The Knowledge training Woollett K, Maguire EA. Acquiring "the Knowledge" of London's layout drives structural brain changes. Curr Biol. 2011 Dec 20;21(24):2109-14. doi: 10.1016/j.cub.2011.11.018. Epub 2011 Dec 8. PMID: 22169537; PMCID: PMC3268356. Neuroplasticity • Ability of the nervous system to change its activity in response to intrinsic or extrinsic stimuli by reorganizing its structure, functions, or connections. Structural vs Functional neuroplasticity Structural Functional • patterns of responsiveness • adjust neuronal morphology • dynamic changes in cellular structures • structural aspects of neuronal connectivity • activity of synapses, neurons, circuits • at the molecular level • • • • presynaptic neurotransmitter release intracellular signalling pathways protein synthesis gene expression The magnitude of synaptic transmission and neuronal firing Structural vs Functional neuroplasticity Structural • Limited • A high degree of structural invariability is an important characteristic of the CNS • Ensures that the circuits remain stable • Specificity of neural connections is protected Low capacity for regeneration and repair Stability Plasticity Does brain plasticity decline with age? The neural basis of language development: Changes inlateralisation over age Olulade et al., Proc Natl Acad Sci U S A. 2020 Sep 22;117(38):23477-23483. doi: 10.1073/pnas.1905590117 White matter in the older brain is more plastic • For changes in the cortex, younger learners showed significantly more than older learners. For changes in white matter, older learners showed significantly more than younger learners. • In volunteers of both age groups, brain changes occurred only in the sections corresponding with the part of the visual field Yotsumoto, Y., Chang, LH., Ni, R. et al. White matter in the older brain is more plastic than in thespecific younger brain. Nat Commun 5, 5504 (2014). https://doi.org/10.1038/ncomms6504 where the patches occurred. When it occurs? Neuroplasticity • • • • Adaptive behaviour Learning Memory Recovery after injury Levels • • • • Molecules/interactions Subcellular/synaptic Cellular Network Neuroplasticity Mechanisms de Vos Cato et al., 2021.DOI=10.3389/fpsyt.2021.724606 At the molecular/cellular level • Neuroplasticity occurs as early as at this level – and this is probably the most immediate way this phenomena occurs. • Neurotransmitters • Receptors/Channels Intrinsic neuroplasticity Mouse Neuron DIV 14 Blue = MAP2 Green = GluN2B At the molecular/cellular level • Increase/decrease number of spines (to receive signals) • Axon branching At the molecular/cellular level • Increase/decrease number of spines (to receive signals) • Axon branching Maximilian Lenz et al., (2021) eLife 10:e63026 https://doi.org/10.7554/eLife.63026 Short-Term Learning Structural Plasticity Diffusion tensor imaging (DTI), a framework of diffusion MRI, provides a multitude of qua indices that reflect the micron-scale density and organization of the tissue. Neuron 2012 731195-1203DOI: (10.1016/j.neuron.2012.01.025) Hebbian plasticity vs Homeostasis • Hebbian plasticity - widely considered to be the mechanism by which information can be coded and retained in neurons • Memories are formed through strengthening of synaptic connections between neurons with correlated activity. Donald O. Hebb (1904 – 1985) “Cells that fire together wire together” • Homeostatic plasticity - synaptic strengths are compensated by altering presynaptic neurotransmitter release and controlling the abundance of postsynaptic receptors. Forrest MP, Parnell E, Penzes P. Dendritic structural plasticity and neuropsychiatric disease. Nat Rev Neurosci. 2018 Mar 16;19(4):215234. doi: 10.1038/nrn.2018.16. PMID: 29545546; PMCID: PMC6442683. Structural plasticity defects in pathology Depiction of dendritic spines from area 46, layer 3, from postmortem human tissue from: A non-schizophrenic individual B and C individual diagnosed with schizophrenia. Glantz LA, Lewis DA. - Arch Gen Psychiatry. 2000 Jan;57(1):65-73. doi: 10.1001/archpsyc.57.1.65. PMID: 10632234. SPINE PATHOLOGIES Forrest MP, Parnell E, Penzes P. Dendritic structural plasticity and neuropsychiatric disease. Nat Rev Neurosci. 2018 Mar 16;19(4):215234. doi: 10.1038/nrn.2018.16. PMID: 29545546; PMCID: PMC6442683. SPINE PATHOLOGIES Forrest MP, Parnell E, Penzes P. Dendritic structural plasticity and neuropsychiatric disease. Nat Rev Neurosci. 2018 Mar 16;19(4):215234. doi: 10.1038/nrn.2018.16. PMID: 29545546; PMCID: PMC6442683. Therapeutic/research – induced plasticity • In ASD • Schizophrenia • Depression • Traumatic brain injury • Alzheimer’s disease • Transcranial magnetic stimulation (TMS) – non-invasive, focal brain stimulation – Induces a small intracranial electric current in the brain – TMS-TBS protocols/PAS paradigm/EEG • Diabetes Induce mechanisms similar to LTP and LTD Jannati, A., Oberman, L.M., Rotenberg, A. et al. Assessing the mechanisms of brain plasticity by transcranial magnetic stimulation. Neuropsychopharmacol. 48, 191–208 (2023). https://doi.org/10.1038/s41386-022-01453-8 Impairment of Neuroplasticity in the Dorsolateral Prefrontal Cortex by Alcohol Loheswaran, G., Barr, M.S., Zomorrodi, R. et al. Impairment of Neuroplasticity in the Dorsolateral Prefrontal Cortex by Alcohol. Sci Rep 7, 5276 (2017). https://doi.org/10.1038/s41598-017-04764-9 Impaired neuroplasticity in the prefrontal cortex in depression Noda, Y, Zomorrodi, R, Vila-Rodriguez, F, et al. Impaired neuroplasticity in the prefrontal cortex in depression indexed through paired associative stimulation. Depression and Anxiety. 2018; 35: 448– 456. https://doi.org/10.1002/da.22738 Anodal transcranial direct current stimulation (atDCS) • Performance accuracy during the semantic word-generation task in the two age groups. • During sham, older adults produced significantly fewer correct exemplars during the task compared with younger adults (i.e., more errors). • During atDCS, performance in older adults improved significantly up to the level of the matched younger control group. Marcus Meinzer, Robert Lindenberg, Daria Antonenko, Tobias Flaisch and Agnes Flöel Journal of Neuroscience 24 July 2013, 33 (30) 12470-12478; DOI: https://doi.org/10.1523/JNEUROSCI.5743-12.2013 Psychadelics and Neuroplasticity • Psychadelics such as: LSD, Psilocybin, DMT-containing beverage ayahuasca, etc. • Show potential to treat depression, anxiety and addiction • Clinical improvements can last for months/years • Psychedelics acutely stimulate structural neuroplasticity processes at a molecular and (sub)cellular level after a single dose. • Dendritogenesis • Synaptogenesis • Expression of plasticity genes (e.g., BDNF) • PFC • Hippocampus Carhart-Harris, R. L., Muthukumaraswamy, S., Roseman, L., Kaelen, M., Droog, W., Murphy, K., ... & Nutt, D. J. (2016). Neural correlates of the LSD experience revealed by multimodal neuroimaging. Proceedings of the National Academy of Sciences, 113(17), 4853-4858. De Vos, C. M., Mason, N. L., & Kuypers, K. P. (2021). Psychedelics and neuroplasticity: a systematic review unraveling the biological underpinnings of psychedelics. Frontiers in psychiatry, 1575. Calder, A.E., Hasler, G. Towards an understanding of psychedelic-induced neuroplasticity. Neuropsychopharmacol. 48, 104–112 (2023). https://doi.org/10.1038/s41386-022-01389-z Thank you Adult neurogenesis Adult neurogenesis (Vivar and van Praag, 2017) La Rosa et al., 2020. Front. Neurosci.,https://doi.org/10.3389/fnins.2020.00075 Thank you