Brendan M. Walker

Brendan M. Walker

Adjunct Associate Professor

Room: Johnson Tower 210/VBR 215
Phone: (509)-335-8526



  • Neurobiology of Motivational Systems
  • Excessive Self-Administration resulting from Alcohol and Drug Dependence
  • Chronic Alcohol and Drug-Induced Depression and Anxiety
  • Alcohol and Drug-Induced Alterations in Impulsivity
  • Plasticity Associated with Negative Reinforcement Mechanisms
  • Molecular and Genetic Determinants of Chronic Alcohol and Drug-related Altered Behavioral  regulation
  • Adolescent Exposure to Alcohol and Drugs of Abuse
  • My long-term research interest has been the neurobiology of motivational systems and how acute and long-term alcohol (and other drugs of abuse such as heroin) impact brain reward systems to promote increased drug seeking and consumption. Utilizing a combination of behavioral, anatomical, pharmacological, immunohistochemical, molecular and genetic approaches, we are currently evaluating the neuroadaptations produced by chronic ethanol and opioid exposure that promote enhanced intake of these abused compounds. This excessive intake is hypothesized to reflect the development of negative reinforcement (learning about the reinforcing (response increasing) nature of aversive stimulus removal that occurs when alcohol and drugs are consumed to relieve acute and protracted withdrawal symptoms) processes that compliment positive reinforcement processes governing non-dependent intake that developed earlier in life. Consequently, we are extremely interested in dependence-induced depression and anxiety because they appear to be lay the foundation for the observed increases in the negative reinforcing properties of abused substances. As an extension of this work, we also focus on the morphological and molecular mechanisms of plasticity associated with negative reinforcement learning. The lab is also investigating differences in impulsivity produced by chronic alcohol and drug exposure, as well as, animal models of adolescent alcohol and drug exposure that impact adult alcohol and drug intake. Once enough information is gathered about the nature of the brain’s response to chronic alcohol and drug exposure, that information can be used to help develop pharmacotherapies for the treatment of alcohol and drug addiction.

    Select Publications
    • Kissler JL, Sirohi S, Reis DJ, Jansen HT, Quock RM, Smith DG, Walker BM (2014) The one-two punch of alcoholism: role of central amygdala dynorphins/kappa-opioid receptors Biol Psychiatry 75(10), 774-82 PMID: 23611261 PMCID: PMC3749293
    • Walker BM, Kissler JL (2013) Dissociable effects of kappa-opioid receptor activation on impulsive phenotypes in wistar rats Neuropsychopharmacology 38(11), 2278-85 PMID: 23689673 PMCID: PMC3773679
    • Berger AL, Williams AM, McGinnis MM, Walker BM (2013) Affective Cue-Induced Escalation of Alcohol Self-Administration and Increased 22-kHz Ultrasonic Vocalizations during Alcohol Withdrawal: Role of Kappa-Opioid Receptors Neuropsychopharmacology 38(4), 647-54 PMID: 23212453 PMCID: PMC3572461
    • Sirohi S, Bakalkin G, Walker BM (2012) Alcohol-induced plasticity in the dynorphin / kappa-opioid receptor system Front Mol Neurosci 5, 95 PMID: 23060746 PMCID: PMC3459013
    • Williams AM, Reis DJ, Powell AS, Neira LJ, Nealey KA, Ziegler CE, Kloss ND, Bilimoria JL, Smith CE, Walker BM. (2012) The Effect of Intermittent Alcohol Vapor or Pulsatile Heroin on Somatic and Negative Affective Indices during Spontaneous Withdrawal in Wistar Rats Psychopharmacology (Berl) 223(1), 75-88 PMID: 22461104 PMCID: PMC3419345
    • Walker BM (2012) Conceptualizing Withdrawal-Induced Escalation of Alcohol Self-Administration as a Learned, Plasticity-Dependent Process Alsohol 46(4), 339-348 PMID: PMCID:
    • Walker BM, Valdez GR, McLaughlin JP, Bakalkin G (2012) Targeting dynorphin/kappa opioid receptor systems to treat alcohol abuse and dependence Alcohol 46(4), 359-70 PMID: 22459870 PMCID: PMC3396024
    • Smith AW, Nealey KA, Wright JW, Walker BM (2011) Plasticity associated with escalated operant ethanol self-administration during acute withdrawal in ethanol-dependent rats requires intact matrix metalloproteinase systems Neurobiol Learn Mem 96(2), 199-206 PMID: 21530666 PMCID: PMC3148339
    • Nealey KA, Smith AW, Davis SM, Smith DG, Walker BM (2011) K-opioid receptors are implicated in the increased potency of intra-accumbens nalmefene in ethanol-dependent rats Neuropharmacology 61, 35-42 PMID: PMCID:
    • Walker BM, Zorrilla EP, Koob GF (2011) Systemic κ-opioid receptor antagonism by nor-binaltorphimine reduces dependence-induced excessive alcohol self-administration in rats Addict Biol 16(1), 116-9 PMID: 20579007 PMCID: PMC2988980
    • Walker JL, Walker BM, Fuentes FM, Rector DM (2011) Rat psychomotor vigilance task with fast response times using a conditioned lick behavior Behavioural Brain Research 216(1), 229-237 PMID: 20696188 PMCID: PMC2975873
    • Walker BM, Drimmer DA, Walker JL, Liu T, Mathé AA, Ehlers CL (2010) Effects of prolonged ethanol vapor exposure on forced swim behavior, and neuropeptide Y and corticotropin releasing factor levels in rat brains Alcohol 44(6), 487-93 PMID: 20705420 PMCID: PMC2954060