Gender	Male
E-mail	john.morrison@mssm.edu
Education and Training	Ph.D., Johns Hopkins University
Awards	2007 - 2017 Merit Award on Glutamate Receptors in Aging Cortical Circuits NIH
	2000 - 2010 Program Project Grant on Estrogen and the Aging Brain NIH

In October, 2006, Dr. Morrison stepped down as Chair of Neuroscience to assume the position of Dean of Basic Sciences and the Graduate School of Biological Sciences at Mount Sinai School of Medicine.

Dr. Morrison is also Professor of Neuroscience and the Willard T. C. Johnson Professor of Geriatrics and Adult Development in Neurobiology of Aging.

Visit Dr. John Morrison's Lab for more information.

Education and Training	Ph.D., Johns Hopkins University

Specific Clinical/Research Interest: Neurobiology of aging, plasticity, and cortical organization. Steroid effects on cortical circuitry and function.

Current Students: PhD: Athena Wang and Megan Bailey. MD/PhD: Dani Dumitriu, Kimberly Kwei.

Postdoctoral Fellows: Rebecca Shansky, Karen Dietz and Yuko Hara.

Research Personnel: Lab Manager: Bill Janssen; Research Assistants: Carine Hamo and Dan Ohm.

Current Research
Cortical Organization, Glutamate Receptors, Aging, and Neurodegenerative Disorders
Our research program includes several related components, with the three primary areas being the cellular and synaptic organization of cerebral cortex, selective vulnerability in neurodegenerative disorders, and age-related alterations in glutamate receptor-mediated cortical circuits. These efforts involve cellular neuropathologic analyses of human brain, experimental and neuropathologic analyses of non-human primate cortex, and detailed neuropathologic analyses of genetically manipulated mice. In both neocortex and hippocampus, we are particularly interested in determining the molecular and structural nature of age-related alterations in synaptic plasticity that lead to compromised cognitive function and/or degeneration. We are also analyzing links between cytoskeletal proteins (e.g., neurofilament proteins) and calcium-binding proteins and selective vulnerability in neurodegenerative disorders in order to elucidate the cellular progression of degeneration in human cortex and animal models. Virtually all of our microscopic analyses are quantitative in nature, and in collaboration with our colleagues at Scripps Research Institute, we have developed several powerful software programs for computer-assisted quantitative microscopy.

Our studies on glutamate receptor-mediated circuits have focused on both neocortex and hippocampus of primates and rodents. Recently, we have been particularly interested in the cellular and molecular events underlying the functional decrements often seen in normal aging, particularly age-related memory impairment. In contrast to Alzheimer's Disease, cell loss is not likely to be a significant contributor to functional decline in normal aging. Shifts in expression and distribution of key molecules (i.e., glutamate receptors) in otherwise intact circuits, however, do appear to be occurring in aging, and in a manner that would have profound effects on synaptic transmission in key hippocampal and neocortical circuits. These alterations in the molecular constituents of the synapse occur against a background of structural alterations of the spines and synapses that also impact function. In a related set of studies, we showed that estrogen-replacement therapy in ovariectomized rodents led to a restoration of NMDA receptor levels in both CA1 pyramidal cells and dentate gyrus granule cells, suggesting a potential molecular substrate for the beneficial effects of estrogen replacement on memory function. We are currently pursuing the links between age-related decreases in estrogen levels (i.e., menopause), NMDA receptors, and cortical circuits, in behaviorally and hormonally characterized aged non-human primates, with a particular focus on prefrontal cortex and related cognitive functions.

Visit Dr. John Morrison's Lab for more information.

Radley JJ, Rocher AB, Rodriguez A, Ehlenberger DB, Dammann M, McEwen BS, Morrison JH, Wearne SL, Hof PR. Repeated stress alters dendritic spine morphology in the rat medial prefrontal cortex. J. Comp. Neurol 2008; 507(1): 1141-1150.

Yildirim M, Janssen WM, Tabori NE, Adams MM, Yuen GS, Akama KT, McEwen BS, Milner TA, Morrison JH. Estrogen and aging affect synaptic distribution of phosphorylated LIM kinase (pLIMK) in CA1 region of female rat hippocampus. Neuroscience 2008; 152(2): 360-370.

Hao J, Rapp PR, Janssen WM, Morrison JH, Lasley BL, Hof PR, Lou W. Interactive effects of age and estrogen on cognition and pyramidal neurons in monkey prefrontal cortex. Proc. Natl. Acad. Sci. USA 2007; 104: 11465-11470.

Park CS, Elgersma Y, Grant SG, Morrison JH. alpha-Isoform of calcium-calmodulin-dependent protein kinase II and postsynaptic density protein 95 differentially regulate synaptic expression of NR2A- and NR2B-containing N-methyl-d-aspartate receptors in hippocampus. Neuroscience 2007; 151: 43-55.

Morrison JH, Gore AC, Schmidt PJ, Brinton RD. Estrogen, menopause, and the aging brain: How basic neuroscience can inform hormone therapy in women. J. Neurosci 2006; 26(41): 10332-10348.

Hao J, Rapp PR, Leffler AE, Leffler SR, Janssen WG, Lou W, Mc Kay H, Roberts JA, Wearne SL, Hof PR, Morrison JH. Estrogen alters spine number and morphology in prefrontal cortex of aged female rhesus monkeys. J Neurosci 2006 Mar; 26(9): 2571-2578.

Moga DE, Morrison JH, Shapiro ML. Bidirectional redistribution of AMPA but not NMDA receptors after perforant path stimulation in the adult rat hippocampus in vivo. Hippocampus 2006; 16(11): 990-1003.

Radley JJ, Sisti HM, Hao J, Rocher AB, Mc Call T, Hof PR, Mc Ewen BS, Morrison JH. Chronic behavioral stress induces apical dendritic reorganization in pyramidal neurons of the medial prefrontal cortex. Neuroscience 2004; 125(1): 1-6.

Wu CC, Chawla F, Games D, Rydel RE, Freedman S, Schenk D, Young WG, Morrison JH, Bloom FE. Selective vulnerability of dentate granule cells prior to amyloid deposition in PDAPP mice: digital morphometric analyses. Proc Natl Acad Sci U S A 2004 May; 101(18): 7141-7146.

Hof PR, Morrison JH. The aging brain: morphomolecular senescence of cortical circuits [review]. Trends Neurosci 2004 Oct; 27(10): 607-13.