PSU Profiles
Last Name

Patricia Grigson-Kennedy

InstitutionCollege of Medicine
DepartmentNeural and Behavioral Sciences
Address500 University Drive Hershey PA 17033
Mailbox: H181


Professor of Neural and Behavioral Sciences


MD/PhD Degree Program, integrative Sciences, Neuroscience


Ph.D., Rutgers University, 1990
Postdoctoral Training, Pennsylvania State University College of Medicine, 1990-1993


A great deal is known about the neural pathways involved in responding to the rewarding properties of food, water, or drugs of abuse, for example. However, these rewards are not typically experienced in a vacuum. At any given time, an animal can engage in a number of different activities, each of which may lead to a different rewarding outcome. The choice to select one behavior over another serves as evidence that very different rewards must be compared by some common neural substrate. However, there currently is little known about the neural pathways involved in such reward comparison processes. It is the focus of this laboratory to identify the substrate.

Rewards are compared in three ways over time. First, a reward can be compared with a different reward that is available closely in time. This form of reward comparison requires short-term memory processes. We have found that a brainstem relay, in particular the nucleus of the solitary tract, is involved in making this type of short-term memory dependent comparison process and that the effect is reflected in the activity of single taste cells in this nucleus (see figures). Second, a reward can be compared with the "memory" of another reward received 24h earlier. This form of reward comparison relies upon long-term memory and necessitates the involvement of the second gustatory relay, the parabrachial nucleus of the pons. Finally, a reward can be compared with another that is expected in the future. The anticipated reward may be a preferred gustatory stimulus or a drug of abuse, such as morphine or cocaine. This phenomenon seems to rely upon more complex associative processes occurring in the forebrain.

Given that drug addiction often is accompanied by an apparent devaluation of that which is naturally rewarding (e.g., relationships, employment, food...), we hope that these efforts will begin to illuminate the neural substrates by which natural rewards and drugs of abuse are compared.

 selected publications
Publications listed below are automatically derived from MEDLINE/PubMed and other sources, which might result in incorrect or missing publications. Faculty can login to make corrections and additions.
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  1. Puhl MD, Blum JS, Acosta-Torres S, Grigson PS. Environmental enrichment protects against the acquisition of cocaine self-administration in adult male rats, but does not eliminate avoidance of a drug-associated saccharin cue. Behav Pharmacol. 2012 Feb; 23(1):43-53.
    View in: PubMed
  2. Puhl MD, Cason AM, Wojnicki FH, Corwin RL, Grigson PS. A history of bingeing on fat enhances cocaine seeking and taking. Behav Neurosci. 2011 Dec; 125(6):930-42.
    View in: PubMed
  3. Liang NC, Freet CS, Grigson PS, Norgren R. Pontine and thalamic influences on fluid rewards: I. Operant responding for sucrose and corn oil. Physiol Behav. 2012 Jan 18; 105(2):576-88.
    View in: PubMed
  4. Liang NC, Grigson PS, Norgren R. Pontine and thalamic influences on fluid rewards: II. Sucrose and corn oil conditioned aversions. Physiol Behav. 2012 Jan 18; 105(2):589-94.
    View in: PubMed
  5. Liang NC, Norgren R, Grigson PS. Pontine and thalamic influences on fluid rewards: III. Anticipatory contrast for sucrose and corn oil. Physiol Behav. 2012 Jan 18; 105(2):595-606.
    View in: PubMed
  6. Puhl MD, Fang J, Grigson PS. Acute sleep deprivation increases the rate and efficiency of cocaine self-administration, but not the perceived value of cocaine reward in rats. Pharmacol Biochem Behav. 2009 Dec; 94(2):262-70.
    View in: PubMed
  7. Twining RC, Bolan M, Grigson PS. Yoked delivery of cocaine is aversive and protects against the motivation for drug in rats. Behav Neurosci. 2009 Aug; 123(4):913-25.
    View in: PubMed
  8. Freet CS, Steffen C, Nestler EJ, Grigson PS. Overexpression of DeltaFosB is associated with attenuated cocaine-induced suppression of saccharin intake in mice. Behav Neurosci. 2009 Apr; 123(2):397-407.
    View in: PubMed
  9. Geddes RI, Han L, Baldwin AE, Norgren R, Grigson PS. Gustatory insular cortex lesions disrupt drug-induced, but not lithium chloride-induced, suppression of conditioned stimulus intake. Behav Neurosci. 2008 Oct; 122(5):1038-50.
    View in: PubMed
  10. Kuntz KL, Twining RC, Baldwin AE, Vrana KE, Grigson PS. Heroin self-administration: I. Incubation of goal-directed behavior in rats. Pharmacol Biochem Behav. 2008 Sep; 90(3):344-8.
    View in: PubMed
  11. Kuntz KL, Patel KM, Grigson PS, Freeman WM, Vrana KE. Heroin self-administration: II. CNS gene expression following withdrawal and cue-induced drug-seeking behavior. Pharmacol Biochem Behav. 2008 Sep; 90(3):349-56.
    View in: PubMed
  12. Wheeler RA, Twining RC, Jones JL, Slater JM, Grigson PS, Carelli RM. Behavioral and electrophysiological indices of negative affect predict cocaine self-administration. Neuron. 2008 Mar 13; 57(5):774-85.
    View in: PubMed
  13. Grigson PS. Reward Comparison: The Achilles' heel and hope for addiction. Drug Discov Today Dis Models. 2008; 5(4):227-233.
    View in: PubMed
  14. Liu C, Grigson PS. Brief access to sweets protect against relapse to cocaine-seeking. Brain Res. 2005 Jul 5; 1049(1):128-31.
    View in: PubMed
  15. Schroy PL, Wheeler RA, Davidson C, Scalera G, Twining RC, Grigson PS. Role of gustatory thalamus in anticipation and comparison of rewards over time in rats. Am J Physiol Regul Integr Comp Physiol. 2005 Apr; 288(4):R966-80.
    View in: PubMed
  16. Jones BC, Wheeler DS, Beard JL, Grigson PS. Iron deficiency in rats decreases acquisition of and suppresses responding for cocaine. Pharmacol Biochem Behav. 2002 Nov; 73(4):813-9.
    View in: PubMed
  17. Grigson PS, Twining RC, Carelli RM. Heroin-induced suppression of saccharin intake in water-deprived and water-replete rats. Pharmacol Biochem Behav. 2000 Jul; 66(3):603-8.
    View in: PubMed
  18. Gomez F, Leo NA, Grigson PS. Morphine-induced suppression of saccharin intake is correlated with elevated corticosterone levels. Brain Res. 2000 Apr 28; 863(1-2):52-8.
    View in: PubMed
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