Dr Sharma is a board certified psychiatrist who is additionally trained in mathematics, statistics and molecular biology. His earlier work examined the neurochemical basis of psychotic symptoms in clinical subjects. These studies included the early measurement of chemicals in the brain (using proton spectroscopy) as well as in CSF and plasma of patients suffering from psychotic disorders. His current NIH sponsored studies are focused on the regulation of gene activity in neurons, using basic models such as cortical neuron cultures. These studies are specifically directed towards elucidating the effects of epigenetic mechanisms on regulation of mRNA and protein levels in neurons, with a priority towards identifying novel therapeutic approaches. He has proposed the possible use of nuclear receptor pharmacology in the treatment of psychiatric and cognitive disorders.

Research Areas of interest:
Psychosis, epigenetic neuron gene regulation, molecular pharmacology, mathematics/statistics.

Representative Publications:

Sharma RP, Javaid JI, Janicak PG: The effect of trifluoperazine on CSF and plasma HVA in schizophrenic subject. American Journal of Psychiatry, 145: 1480-l481, l988.

Sharma RP, Pandey GN, Janicak PG, Peterson J, Comaty J, Davis JM: The effect of diagnosis and age on the DST: A meta-analytic approach. Biological Psychiatry 24:555-568, l988.

Sharma RP, Javaid JI, Janicak PG, Faull K, Comaty J, Davis JM: CSF and plasma HVA before and after pharmacological treatment Psychiatry Research Vol. 28; p. 97-l04, l989).

Sharma RP, Janicak PG, Javaid JI, Pandey GN, Gierl B, Davis JM: Platelet MAO inhibition, Urinary MHPG, and Leukocyte B-adrenergic receptors in depressed patients treated with phenelzine. American Journal of Psychiatry Vol. 147:10, 1322-1326, 1990.

Sharma RP, Javaid JI, Pandey GN, Janicak PG, Davis, JM: Behavioral and Biochemical effects of Methylphenidate in schizophrenic and non-schizophrenic patients. Biological Psychiatry 30: p 459-466 1991.

Sharma RP, Hedeker D, Pandey GN, Janicak PG, Davis JM: A longitudinal study of plasma cortisol and depressive symptomatology by Random Regression analysis. Biological Psychiatry Vol 31; 304-314,1992).

Sharma RP, Venkatsubramanian PN, Barany M, Davis JM. Proton Magnetic Resonance Spectroscopy of the brain in schizophrenic and affective patients. Schizophrenia Research Vol 8, 43-49, 1992.

Sharma RP, Javaid JI, Janicak PG, Davis JM, Faull K: Homovanillic acid in the cerebrospinal fluid: Patterns of response after four weeks of neuroleptics Biological Psychiatry Vol 34; p 128-134, 1993.

Sharma RP, Javaid JI, Faull K, Davis JM, Janicak PG: CSF, plasma, and the CSF MHPG index: Diagnostic differences and response to somatic treatments Psychiatry Research vol 51: 51-60, 1994.

Sharma RP, Bissette G, Janicak PG, Davis JM, Nemeroff C. Cerebrospinal somatostatin concentrations in schizophrenia and schizoaffective disorder: The effects of antipsychotic treatment Schizophrenia Research vol 13: 173-178, 1994.

Sharma RP, Faull K, Javaid JI, Davis JM. Cerebrospinal fluid levels of Phenylacetic acid in psychiatric illness: Behavioral associations and response to neuroleptic treatment. Acta Psychiat Scand91: 293-298, 1995.

Sharma RP, Bissette G, Janicak PG, Davis JM, Nemeroff C. Elevation of Cerebrospinal fluid Somatostatin in Mania (Amer J Psychiat 152: 12, p 1807-1809, 1995).

Sharma RP, Dowd S., Davis JM., Janicak PG. Age of illness onset and nature of schizophrenic symptomatology. Schiz Research20: p295-300, 1996.

Sharma RP, Kamath S, Shapiro L, Soll E, Watanabe M, Davis JM. Acute Dietary Tryptophan Depletion: Effects on Schizophrenic Positive and Negative Symptoms. (Neuropsychobiology 35: p5-10; 1997).

Sharma RP., Javaid JI., Davis JM., Janicak PG. Pretreatment Plasma Homovanillic Acid in Schizophrenia and Schizoaffective disorder: The influence of Demographic Variables and the Inpatient Drug-Free Period. Biol Psychiatry. 44: p488-492: 1998.

Impagnatiello F., Guidotti A., Pesold C., Dwivedi Y., Cauncho H., Pisu M., Uzunov D., Smalheiser N., Davis J., Pandey G., Pappas G., Tueting P., Sharma RP., Costa E. A decrease of Reelin Expression as a putative vulnerability factor in schizophrenia. (Proceedings of the National Academy of Sciences. Vol. 95: pp15718-15723, Dec 1998.

Sharma RP., Dowd SM., Janicak PG. Hallucinations in the acute schizophrenic type psychosis: effects of gender and age of illness onset. Schiz Res 37; p91-95, 1999.

Sharma RP., Vivek Singh., Janicak PG., Javaid JI., Pandey GN. The prolactin response to fenfluramine in schizophrenia is associated with negative symptoms. Schiz Res 39; p85-89; 1999.

Guidotti A., Auta J., Davis J., Gerevini, V.D., Dwivedi Y.,Grayson D., Impagtnatiello F., Pandey G., Pesold C., Sharma RP., Uzunov DP., Costa E. Decrease in Reelin and Glutamic Acide Decarboxylase 67 (GAD67) Expression in Schizophrenia and Bipolar Disorder. Arch. Gen. Psychiatry. 57; 1061-1069; 2000.

Sharma RP., Martis B., Davis JM., Omens, R., Janicak PG. Tiagabine, a specific GABA transporter 1 (GAT 1) inhibitor in the treatment of psychosis. Journal Clin Psychopharm. vol21;3; p347-349, 2001.

Sharma RP., Martis B., Rosen C., Janardhan J., Nemeroff C., Bissette G. CSF Thyrotropin-releasing hormone concentrations differ in patients with schizoaffective disorder from patients with schizophrenia. Journal of Psychiatric Research 35; 287-291; 2001.

Chen Y., Sharma RP., Costa R.H., Costa E. and Grayson D.R. On the epigenetic regulation of human reelin promoter expression. Nucleic Acids Research. 30(13):2930-2939, 2002

Tremolizzo L, Carboni G, Ruzicka WB, Mitchell CP, Sugaya I, Tueting P, Sharma RP, Grayson DR, Costa E, Guidotti A. An epigenetic mouse model for molecular and behavioral neuropathologies related to schizophrenia vulnerability. Proc Natl Acad Sci U S A. 2002 Dec 24;99(26):17095-100.

Sharma RP. Schizophrenia, Epigenetics and Ligand activated nuclear transcription factors: A framework for chromatin therapeutics. Schizophrenia Research. 2005, Jan 1; 72 (2-3): 79-90.

Gibbons RD, Bhaumik DK, Cox DR, Grayson DR, Davis JM, Sharma RP. Sequential prediction bounds for identifying differentially expressed genes in replicated microarray experiments. Journal of Statistical Planning and Inference. 129; 19-37: 2005.

Noh JS, Sharma RP, Veldic M, Salvacion AA, Jia X, Chen Y, Costa E, Guidotti A, Grayson DR. DNA methyltransferase 1 regulates reelin mRNA expression in mouse primary cortical cultures. Proc Natl Acad Sci U S A. Feb 1,vol 102, 1749-1754 2005.

Sharma RP., Grayson, DR, Guidotti, A., Costa E. Chromatin, DNA methylation, and neuron gene regulation - the purpose of the package. Journal of Psychiatry and Neuroscience 30 (4):273-63: 2005

Grayson DR., Jia, X., Chen, Y., Sharma RP., Mitchell CP., Guidotti A, Costa E. Promoter Hypermethylation in Schizophrenia, (Proc Natl Acad Sci U S A, Jun 28;102(26): 9341-6 2005).

Sharma RP, Rosen CR, Kartan S, Guidotti A, Costa E, Grayson D, Chase K. Valproic acid and chromatin remodeling in schizophrenia and bipolar disorder: preliminary results from a clinical population. Schizophrenia Research, Dec;88(1-3):227-31 2006.

Sharma RP, Grayson DR, Gavin D. Histone deactylase 1 expression is increased in the prefrontal cortex of schizophrenia subjects: Analysis of the National Brain Databank microarray collection, Schizophr. Res. (2007), doi:10.1016/j.schres.2007.09.020

Sharma RP. Kartan S. Grayson DR. Depolarization induces down-regulation of dnmt1 mrna in primary cortical cultures (in prep).

Imbesi M, Zavoreo I, Uz T, Sharma RP, Dimitrijevic N, Manev H, Manev R. 5-Lipoxygenase inhibitor MK-886 increases GluR1 phosphorylation in neuronal cultures in vitro and in the mouse cortex in vivo. Brain Res. 2007 May 25;1147:148-53.