Ph.D. Graduate (2014)
BS Neurobiology (2006) University of Wisconsin-Madison
Training Dates at OHSU
The effect of a neuroactive steroid analog and an extrasynaptic GABAA receptor agonist on ethanol self-administration in mice
Awards and Grants Received
OHSU Graduate Research Scholarship (2011)
N.L. Tartar Trust Fellowship (2011)
Pre-doctoral individual National Research Service Award (2012-2014)
Ashworth Award (2012)
Research Society on Alcoholism Memorial Award (2014)
Post-doctoral fellow at the University of Chicago in the laboratory of Dr. Stephanie Dulawa
My thesis work, performed in the laboratory of Dr. Deborah Finn, focused on the influence of the neurosteroid environment and extrasynaptic GABAA receptor activation on ethanol intake in mice. These studies showed that a neurosteroid analog (ganaxolone) and GABAA receptor agonist with selectivity for extrasynaptic receptors (gaboxadol) altered ethanol reinforcement across various self-administration procedures in mice (continuous-access, limited-access, operant, reinstatement). Although both drugs decreased ethanol intake in all procedures, the neurosteroid was unique in that is increased ethanol seeking and initial intake, prior to decreasing intake. This work was important because it suggested that extrasynaptic GABAA receptor activation alone was not sufficient to induce ethanol seeking. Additionally, these studies provided important information about potential ethanol-seeking effects resulting from a drug (ganaxolone) that is being used in clinical trials for diseases co-morbid with alcohol use disorders. The results of my work showed that infusions into nucleus accumbens shell mimic effects seen after systemic or lateral ventricle manipulation, indicating the nucleus accumbens shell may be an important substrate in GABAA receptor alterations of ethanol reinforcement.
The goal of my post-doctoral work is to elucidate the molecular mechanisms and neural circuitry underlying a serotonin2C receptor agonist in its actions as fast-onset antidepressant. Using Brain-Derived Neurotrophic Factor (BDNF) floxed mice, I am knocking down BDNF in specific brain regions to examine the necessity of BDNF in mediating the fast-onset antidepressant effect. I am also using DREADDs to activate specific ventral tegmental area (VTA) projection neurons to understand which pathways are involved in the fast-onset antidepressant response.
Ramaker MJ, Strong-Kaufman MN, Ford MM, Phillips TJ, Finn DA. (2014) Effect of nucleus accumbens shell infusions of ganaxolone or gaboxadol on ethanol consumption in mice. Psychopharm [epub ahead of print] [PMID: 25342197].
Snelling C, Tanchuck-Nipper MA, Ford MM, Jensen JP, Cozzoli DK, Ramaker MJ, Helms M, Crabbe JC, Rossi DJ, Finn DA (2014) Quantification of ten neuroactive steroids in plasma in Withdrawal Seizure-Prone and -Resistant mice during chronic ethanol withdrawal. Psychopharm 231(17):3401-14 [PMCID: 4134998 Available on 2015/9/1].
Ramaker MJ, Strong, MN, Ford MM, Phillips TJ Finn DA (2014) Differences in the reinstatement of ethanol seeking with ganaxolone and gaboxadol. Neuroscience 272:180-7 [PMCID: PMC4122668 Available on 2015/7/11].
Ramaker MJ, Strong, MN, Ford MM, Finn DA (2012) Effect of ganaxolone and THIP on operant and limited-access ethanol self-administration. Neuropharmacology 63(4):555-64 [PMCID: PMC3656651].
Davies DL, Bortolato M, Finn DA, Ramaker MJ, Barak S, Ron D, Liang J, Olsen RW (2012) Recent advances in the discovery and preclinical testing of novel compounds for the prevention and treatment of alcohol use disorders. Alcoholism: Clinical and Experimental Research 37(1):8-15 [PMCID: PMC3443504].
Yardley M, Wyatt L, Khoja S, Asatryan L, Ramaker MJ, Finn DA, Alkana RL, Huynh N, Louie SG, Petasis NA, Bortolato M, Davies DL (2012) Ivermectin reduces alcohol intake and preference in mice. Neuropharmacology 63(2):190-201 [PMCID: PMC3372603].
Ramaker MJ, Ford MM, Fretwell AM, Finn DA (2011) Alteration of ethanol drinking in mice via modulation of the GABAA receptor with ganaxolone, finasteride, and gaboxadol. Alcoholism: Clinical and Experimental Research 35(11):1994-2007 [PMCID: 3173599].
Alsene KM, Rajbhandari, Ramaker MJ, Bakshi VP (2011) Discrete forebrain neuronal networks supporting noradrenergic regulation of sensorimotor gating. Neuropsychopharmacology 36(5):1003-14 [PMCID: 3077269].
Page last updated: November 11, 2014