Dr. Robert Gannon

Contact Information

Dr. Gannon's Courses Website

Email: rlgannon@valdosta.edu

OK Kids - Time to Move! Maybe we went too far...

Ok Kids – Time to move!

Maybe we went too far


Education

Ph.D. Neuropharmacology
University of Texas Medical Branch
Galveston, TX

B.S. Aquatic Biology and Chemistry
Northern Arizona University
Flagstaff, AZ

My Research

Circadian Neurobiology Research Laboratory

Many physiological processes such as the sleep/wake cycle, hormone release, feeding and metabolism occur in cycles that are nearly twenty-four hours long. Cycles such as these are referred to as circadian ("about a day") rhythms, and my laboratory investigates the physiology of mammalian circadian rhythms. Circadian rhythms in mammals are generated by a set of pacemaker cells located within a paired set of nuclei situated just above the optic chiasm in the brain. These nuclei are called the suprachiasmatic nuclei, and the pacemaker cells within these nuclei generate a twenty-four rhythm that is synchronized with the organism's day/night cycle. These pacemaker cells also synchronize the timing of other pacemaker cells throughout the body so that all of the body's clocks are running at the same time.

My undergraduate students and I utilize a variety of techniques to research how external stimuli will affect the timing of the circadian clock, but most notably the laboratory utilizes behavioral pharmacology as the primary research tool, with neuroanatomical studies complementing the behavioral work. This research is relevant not only as a basic science study of circadian rhythms, but it also has medical applications for the treatment of travel and shift-work related fatigue, sleep disorders, and home care of early stage Alzheimer's patients. My laboratory has been supported by awards from the National Science Foundation since 1997.

Memberships

Society for Neuroscience
Faculty for Undergraduate Neuroscience
Council on Undergraduate Research
Serotonin Club
International Brain Research Organization
American Association for the Advancement of Science

Publications

Articles in Peer-Reviewed Journals:

  1. Snell, LD, Mueller, ZL, GANNON, RL, Silverman, PB, Johnson, KM:  A comparison between classes of drugs having phencyclidine-like behavioral properties on dopamine efflux in vitro and dopamine metabolism in vitro.  J. Pharmacol. Exp. Ther. 1984; 231:  261-269.
  2. GANNON, RL, Baty, LT, Terrian, DM:  L(+)-2-Amino-4- phosphonobutyrate inhibits the release of both glutamate and dynorphin from guinea pig but not rat hippocampal mossy fiber synaptosomes.  Brain Res. 1989; 495:  151-155.
  3. GANNON, RL, Terrian, DM:  BOAA enhancement of L-glutamate release from guinea pig hippocampal mossy fiber synaptosomes.  Neuroscience Lett. 1989; 107:  289-294.
  4. Terrian, DM, Damron, DS, Dorman, RV, GANNON, RL:  Effects of calcium antagonists on the evoked release of dynorphin A(1-8) and availability of intraterminal calcium in rat hippocampal mossy fiber synaptosomes.  Neuroscience Lett. 1989; 106:  322-327.
  5. Terrian, DM, GANNON, RL, Rea, MA:  Glutamate is the endogenous amino acid selectively released by rat hippocampal mossy fiber synaptosomes concomitant with prodynorphin-derived peptides.  Neurochem. Res. 1990; 15:  1-5.
  6. Terrian, DM, Dorman, RV, GANNON, RL: Characterization of the presynaptic calcium channels involved in glutamate exocytosis from rat hippocampal mossy fiber synaptosomes. Neurosci. Lett. 1990; 119: 211-214.
  7. GANNON, RL, Terrian, DM:  Presynaptic modulation of glutamate and dynorphin release by excitatory amino acids in the guinea pig hippocampus. Neuroscience 1991; 41: 401-410.
  8. Terrian, DM, Dorman, RV, Damron, DS, GANNON, RL: Displacement of endogenous glutamate with D-aspartate: an effective strategy for reducing the calcium-independent component of glutamate release from synaptosomes.  Neurochem. Res. 1991; 16: 35-41.
  9. GANNON, RL, Terrian, DM: U-50,488H inhibits dynorphin and glutamate release from guinea pig hippocampal mossy   fiber terminals. Brain Res. 1991; 548: 242-247.
  10. Terrian, DM, Ways, DK, GANNON, RL: A presynaptic role for protein kinase C in hippocampal mossy fiber synaptic transmission. Hippocampus. 1991; 1: 303-314.
  11. Terrian, DM, Conner-Kerr, TA, Privette, TH, GANNON, RL: Domoic acid enhances the K+-evoked release of endogenous glutamate from guinea pig hippocampal mossy fiber synaptosomes. Brain Res. 1991; 551: 303-307.
  12. GANNON, RL, Terrian, DM: Kappa opioid agonists inhibit transmitter release from guinea pig hippocampal mossy fiber synaptosomes. Neurochem. Res. 1992; 17: 741-747. 
  13. Simpson, JN, GANNON, RL, McGinty, JF, Terrian, DM: Kainic acid depresses the ex vivo release of dynorphin  and glutamate from rat hippocampal
    mossy fiber synaptosomes. Neurosci. Lett. 1992; 137: 149-153.
  14. Terrian, DM, Ways, DK, GANNON, RL, Zetts, DA: Transduction of a protein kinase C-generated signal  into the long-lasting facilitation of glutamate release. Hippocampus 1993; 3: 205-220.
  15. GANNON, RL , Rea, MA:  Glutamate receptor immunoreactivity in the rat suprachiasmatic nucleus. Brain Res. 1993; 622: 337-342.
  16. GANNON, RL , Rea, MA: In situ hybridization of antisense mRNA oligonucleotides for AMPA, NMDA and metabotropic glutamate receptor subtypes in the rat suprachiasmatic nucleus at different phases of the circadian cycle. Mol. Brain Res. 1994;  23: 338-344.
  17. GANNON, RL, Rea, MA: Twelve hour phase shifts of hamster circadian rhythms elicited by voluntary wheel running. J. Biol. Rhythms 1995; 10: 196-210.
  18. Rea, MA, Barerra, J, Glass, DJ, GANNON, RL: Serotonergic potentiation of photic phase shifts of the circadian activity rhythm. Neuroreport 1995; 6: 1289-1292.
  19. Weber, ET, GANNON, RL, Michel, AM, Gillette, MU, Rea, MA: Nitric oxide synthase inhibitor blocks light-induced phase shifts of the circadian activity rhythm, but not c-fos expression in the suprachiasmatic nucleus of the syrian hamster.Brain Res. 1995; 692: 137-142.
  20. GANNON, RL, Cato, MJ, Hart-Kelley, K, Armstrong, DL, Rea, MA: Circadian variability and GABAergic modulation of optic nerve-evoked field potentials in the rat suprachiasmatic nucleus. Brain Res. 1995; 694: 264-270.
  21. Weber, ET, GANNON, RL, Rea, MA: cGMP-dependent protein kinase inhibitor blocks light-induced phase advances of circadian rhythms in vivo.
    Neurosci. Lett. 1995; 197: 1-4.
  22. Weber, ET, GANNON, RL, Rea, MA: Local Administration of serotonin agonists blocks light-induced phase advances of the circadian activity rhythm in the hamster. J. Biol. Rhythms 1998; 13: 209-218.
  23. *Byku, M, *Legutko, R, GANNON, RL: Distribution of d opioid receptor immunoreactivity in the hamster suprachiasmatic nucleus and intergeniculate leaflet. Brain Res. 2000; 857: 1-7.
  24. *Byku, M, GANNON, RL: SNC 80, a delta-opioid agonist, elicits phase advances in hamster circadian activity rhythms. NeuroReport 2000; 11: 1449-1452.
  25. *Byku, M, GANNON, RL: Opioid induced non-photic phase shifts of hamster circadian activity rhythms. Brain Res. 2000; 873: 189-196.
  26. *Byku, M, GANNON, RL: Effects of the 5HT1A agonist/antagonist BMY 7378 on light-induced phase advances in hamster circadian activity rhythm during aging. J. Biol. Rhythms 2000; 15: 300-305.
  27. GANNON, RL: 5HT7 receptors in the rodent suprachiasmatic nucleus. A mini-review. J. Biological Rhythms. J. Biol. Rhythms. 2001; 16: 19-24.
  28. *Legutko, R, GANNON, RL: Serotonin transporter localization in the hamster suprachiasmatic nucleus. Brain Res. 2001; 893: 77-83.
  29. *Tierno, A, *Fiore, P, GANNON, RL: Delta opioid inhibition of light-induced phase advances in hamster circadian activity rhythms. Brain Res. 2002; 937: 66-73.
  30. *Fiore, P, GANNON, RL: Expression of the transcriptional coactivators CBP and p300 in the hamster suprachiasmatic nucleus: possible molecular components of the mammalian circadian clock. Mol. Brain Res. 2003; 111: 1-7.
  31. GANNON, RL: Serotonergic serotonin1A mixed agonists/antagonists elicit large-magnitude phase shifts in hamster circadian wheel-running rhythms. Neuroscience 2003; 119: 567-576.
  32. GANNON, RL, Millan, MJ: The selective tachykinin neurokinin 1 (NK1) receptor antagonists, GR 205,171, stereospecifically inhibits light-induced phase advances of hamster circadian activity rhythms.  European J.Pharmacol. 2005; 527: 86-93.
  33. GANNON, RL, Millan, MJ: Serotonin1A autoreceptor activation by S 15535 enhances circadian activity rhythms in hamsters: evaluation of potential interactions with serotonin2A and serotonin2C receptors. Neuroscience 2006; 137: 287-299.
  34. GANNON, R.L., Millan, M.J. The corticotropin-releasing factor (CRF1) receptor antagonists CP154,526 and DMP695 inhibit light-induced phase advances of hamster circadian activity rhythms. Brain Research 2006; 1083: 96-102.   
  35. GANNON, R.L.and Millan, M.J. Evaluation of serotonin, noradrenaline and dopamine reuptake inhibitors on light-induced phase advances in hamster circadian activity rhythms. Psychopharmacology 2007; 195: 325-332, 2007.
  36. Sanford, A.E., *Castillo, E., GANNON, RL. 2008. Cannabinoids and hamster circadian activity rhythms. Brain Research 2008; 1222:141-148.
  37. Gorbet, A., Brocco, M., Dekeyne, A., Di Cara, B., Bouchez, G., Lejeune, F., GANNON, R.L., & Millan, M.J. Neurokinin Antagonists Potentiate Antidepressant Properties of Serotonin Reuptake Inhibitors, Yet Blunt Their Anxiogenic Actions: A Neurochemical, Electrophysiological, and Behavioral Characterization. Neuropsychopharmacology 2009; 34: 1039-1056. In press.
  38. *Lungwitz, E., Gannon, RL. Serotonin1A-mediated amplification of light-induced phase advances of circadian rhythms in the Syrian hamster: post-light effects. Brain Research. 1250: 157-163, 2009.
  39. Gannon, R.L., Peglio, J-L., Millan, M.J. Differential influence of selective 5-HT5A vs 5-HT1A, 5-HT1B, or 5-HT2C receptor blockade upon light-induced phase shifts in circadian activity rhythms: interaction studies with citalopram. European Neuropsychopharmacology, 2009; 19: 887-897.
  40. Gannon, R.L., Millan, M.J. Positive and negative modulation of circadian activity rhythms by mGluR5 and mGluR2/3 metabotropic glutamate receptors. Neuropharmacology, 2011; 60:209-215. DOI:10.1016/j.neuropharm.2010.08.022.
  41. Gannon, R.L., *Lungwitz, E., *Batista, N., Hester, I., Huntley, C, *Peacock, A., Delagrange, P. The Benzodiazepine Diazepam Demonstrates the Usefulness of Syrian Hamsters as a Model for anxiety Testing:  Evaluation of other Classes of Anxiolytics in Comparison to Diazepam. Behavioural Brain Research. 2011; 218:8-14.
  42. Gannon, RL and Millan, MJ. Positive allosteric modulators at GABAB receptors exert intrinsic actions and enhance the influence of baclofen on light-induced phase shifts of hamster circadian activity rhythms. Pharmacology, Biochemistry and Behavior, 2011; 99:712-717.
  43. Gannon, RL, Millan, MJ, LY2033298, a positive allosteric modulator at muscarinic M4 receptors, enhances Inhibition by Oxotremorine of Light-Induced Phase Shifts in hamster Circadian Activity Rhythms. Psychopharmacology, 2012; 224:231-240.
  44. Gannon, RL, Garcia, DA*, Millan, MJ. Effects of systemically applied nAChRα7 agonists and antagonists on light-induced phase shifts of hamster circadian activity rhythms. European Neuropsychopharmacology, In Press.
  45. Gannon, RL. Non-Peptide Oxytocin Receptor Ligands and Hamster Circadian Wheel Running Rhythms Brain Research, 2014: In Press.

*undergraduate students

Books and Chapters:

  1. GANNON, RL, Leonard, RB:  Evidence for two pharmacologically distinct populations of glutamate-activated first order interneurons in a vertebrate spinal cord.  In:  EXCITATORY AMINO ACID TRANSMISSION, T.P. Hicks, D. Lodge and H. McLennan (eds.). Alan Liss, New York, pp. 357-360, 1987.    

Other:

  1. Letter to the Editor: The Scientist 2004; 18(9): A4.  

Abstracts/Presentations:

  1. GANNON, RL, Leonard, RB:  N-methyl-D-aspartate excitation of spinal reflexes in vitro in the Atlantic stingray, Dasyatis sabinaFed. Proc. 1985; 44:  1338.
  2. GANNON, RL, Leonard, RB:  Ionophoretic investigation of excitatory amino acids on dorsal horn interneurons in a elasmobranch in vivo.  Excitatory Amino Acid Transmission, Satellite Symposium to the XXX IUPS Congress, 1986.
  3. GANNON, RL, Leonard, RB:  Actions of ionophoretically applied excitatory amino acids on dorsal horn interneurons in the Atlantic stingray, Dasyatis sabina, in vivo.  10th Annual Meeting, Texas Pharmacologists, 1986.
  4. GANNON, RL, Leonard, RB:  GABAergic involvement in primary afferent depol-arization in an elasmobranch spinal cord in vitro. Trans. Soc. Neurosci. 1986; 12:  250.
  5. GANNON, RL, Leonard, RB:  Selective actions of excitatory amino acid antagonists on vertebrate dorsal horn field potentials in vitroXth International Congress of Pharmacology, Sydney, Australia, P4-P125, 1987.
  6. GANNON, RL, Leonard, RB:  Facilitation of spinal reflexes by excitatory amino acids in an elasmobranch spinal cord, in vitroSatellite Symposium to IUPHAR, Canberra, Australia, 1987.
  7. GANNON, RL, Leonard, RB:  Excitatory amino acid mediation of spinal reflexes in an in vitro elasmobranch spinal cord.  The Pharmacologist 1987; 29:  104.
  8. GANNON, RL, Leonard, RB:  Regional selectivity of excitatory amino acid antagonists in the vertebrate dorsal horn.  Trans. Soc. Neurosci. 1987; 13:  764.
  9. GANNON, RL, Baty, LT, Terrian, DM:  Modulation of glutamate and dynorphin release from hippocampal mossy fiber synaptosomes.  Trans. Soc. Neurosci. 1988; 14: 1095.
  10. Hernandez, PG, GANNON, RL, Rea, MA, Terrian, DM:  Adenosine inhibition of glutamate and dynorphin release from hippocampal mossy fiber synaptosomes.  Trans. Soc. Neurosci. 1988; 14:  1095.
  11. Terrian, DM, Dorman, RV, GANNON, RL:  Effects of calcium antagonists on the evoked release of glutamate and dynorphin from hippocampal synaptosomes  J. Neurochem. 1989; 52(Suppl):  S48.
  12. GANNON, RL, Terrian, DM:  Effects of excitatory amino acids on basal and stimulated release of glutamate and dynorphin from hippocampal mossy fiber synaptosomes.  J. Neurochem. 1989; 52(Suppl):  S70.
  13. GANNON, RL, Terrian, DM:  BOAA enhancement of L-Glutamate release from guinea pig hippocampal mossy fiber synaptosomes.  Trans. Soc. Neurosci. 1989; 15:  766.
  14. Terrian, DM, GANNON, RL, Rea, MA:  Glutamate is the amino acid selectively released by rat hippocampal mossy fiber synaptosomes concomitant with prodynorphin-derived peptides.  Therapy with Amino Acids and Analogues:  1st International Congress.  Vienna, Austria, 1989.
  15. Terrian, DM, Damron, DS, GANNON, RL, Dorman, RV:  Characterization of calcium channels in rat hippocampal mossy fiber synaptosomes.  Trans. Soc. Neurosci. 1989; 15:  474.
  16. Terrian, DM, GANNON, RL: Glutamate autoregulation of the hippocampal mossy fiber synapse. The New York Academy of Sciences Symposium on Presynaptic Receptors and the Question of Autoregulation of Neurotransmitter Release. 1989.
  17. Irwin, LN, GANNON, RL, Terrian, DM:  Depolarization displaces synaptosomal gangliosides.  Trans. Am. Soc. Neurochem., 1990; 21: 342.
  18. Terrian, DM, Ways, DK, GANNON, RL:  Evidence for a presynaptic role of protein kinase C in hippocampal mossy fiber synaptic transmission.  Trans. Soc. Neurosci. 1990; 16: 144.
  19. GANNON, RL, Terrian, DM: Presynaptic inhibition of hippocampal mossy fiber synaptic transmission by kappa opioids. Trans. Soc. Neurosci. 1990; 16: 367.
  20. Privette, TH, Terrian, DM, Zetts, DA, Dorman, RV, GANNON, RL: Kappa opioid autoregulation of the guinea pig hippocampal mossy fiber synapse.
    Trans.Am. Soc. Neurochem. 1991; 22: 221.
  21. Conner-Kerr, TA, GANNON, RL, Privette, TH, Patel, MH, Terrian, DM. Domoic acid enhances neurotransmitter release from hippocampal mossy fiber synaptosomes. Trans. Am. Soc. Neurochem. 1991; 22: 238.
  22. Simpson, JN, GANNON, RL, McGinty, JF, Terrian, DM: Kainic acid causes dissociation between the steady-state concentration and the KCl-evoked
    release of dynorphin B and glutamate from rat hippocampal mossy fiber synaptosomes. Trans. Soc. Neurosci. 1991; 17: 412.
  23. Rea, MA, GANNON, RL. Distribution of excitatory amino acid receptor immunoreactivity in the rat suprachiasmatic nuclei. J. Neurochem. 1993;
  24. GANNON, RL, Rea, MA: Expression of NMDA and AMPA glutamate receptor mRNA in the rat SCN at two circadian phases. Trans. Soc. Neurosci. 1993; 19:573.
  25. Earnest, DJ, DiGiorgio, S, Gallagher, MJ, GANNON, RL, Rea, MA. Establishment and characterization of an immortal cell line derived from the rat SCN.Trans. Soc. Neurosci. 1993; 19: 1056.
  26. GANNON, RL, Rea. MA. Twelve hour phase shifts in hamster circadian rhythms elicited by voluntary wheel running. Society for Research on Biological Rhythms.1994.
  27. Erlander, MG, Foye, PE, Danielson, PE, Carson, MJ, Cagle, MP, GANNON, RL, Rea, MA, Sutcliffe, JG. Cloning of differentially expressed genes within hamster suprachiasmatic nucleus (SCN) in response to light entrainment. Trans.Soc. Neurosci. 1994; 20: 159.
  28. GANNON, RL, Rea, MA. Serotonergic mixed 5HT1A agonists/antagonists potentiate light-induced phase shifts of hamster circadian activity rhythms.Trans.Soc. Neurosci. 1995; 21: 180.
  29. Rea, MA, Cato, M, Michel, AM, GANNON, RL. Lesions of the intergeniculate leaflet block serotonergic potentiation of light-induced phase advances of hamster circadian activity rhythms. Trans. Soc. Neurosci. 1995; 21: 179.
  30. Weber, ET, Michel, AM, GANNON, RL, Scott, PA, Rea, MA. Local 5HT-1A/5HT-7 agonists dose-dependently attenuate light-induced phase advances of the suprachiasmatic nucleus in vivo. Society for Research on Biological Rhythms. 1996
  31. Weber, ET, Michel, AM, GANNON, RL, Rea, MA. Local serotonin agonists dose-dependently attenuate light-induced phase advances of circadian activity rhythms in hamsters. Trans. Soc. Neurosci. 1996, 22: 1141.
  32. Weber, ET, GANNON, RL, Cagle, MA, Rea, MA. Pindolol and propranolol attenuate light-induced phase shifts of the circadian activity rhythm in hamsters via a putative serotonergic mechanism. Trans. Soc. Neurosci. 1997, 23: 240.
  33. Byku, M, Tierno, A, GANNON, RL. Opioid inhibition of photic phase advances in hamster circadian activity rhythms. Trans. Soc. Neurosci. 1998, 24: 1186.
  34. Byku, M, GANNON, RL. Opioid-induced nonphotic phase shifts of hamster circadian activity rhythms. Trans. Soc. Neurosci. 1999, 25: 1887.
  35. GANNON, RL. The Role of 5-HT7 Receptors in Circadian Rhythms. Symposium Presentation at Fifth IUPHAR Satellite Meeting on Serotonin, Acapulco, MX 2002
  36. GANNON, RL. Serotonergic potentiation of photic and nonphotic phase shifts in circadian activity rhythms of the Syrian hamster. Trans Soc. Neurosci. 2002 (on CD).
  37. GANNON, RL., Millan, MJ. Influence of selective serotonin reuptake inhibitors (SSRIs) upon hamster circadian activity rhythms. Sixth IUPHAR Satellite Meeting on Serotonin, Sapporo, Japan. J. Pharmacological Sci. 101 Supp.I: 102,2006.
  38. GANNON, RL. Circadian Rhythms and Depression, Insitut de Recherce Servier, Croissy-sur-Seine, France 2006.
  39. Sanford, AE., Millan, MJ, Dekeyne, A., Gobert, A., GANNON, RL. Potential interactions between Corticocotropin Releasing Factor1 (CRF1) receptors and 5-HT reuptake inhibitos (SSRIs) in the control of circadian rhythms and mood.  Trans. Soc. Neurosci. 2006 (on CD)
  40. Castillo, E., GANNON, RL. Post-light temporal efficacy of 5-HT1A-mediated potentiation of circadian phase shifts in the Syrian hamster. Trans. Soc. Neurosci. 2007, on CD.
  41. GANNON, RL, Sanford, A, Castillo, E. Cannabinoid modulation of hamster circadian activity rhythms. International Behavioral Neuroscience Society. 2008.
  42. GANNON, RL, Peglio, J-L, Millan, MJ. Citalopram inhibition of light-induced phase shifts in hamster circadian activity rhythms: modulation by 5-HT receptor antagonists. Fund. Clin. Pharmacol. 2008.
  43. Batista, N, Millan, MJ, Delagrange, P, GANNON, RL. Evaluation of the Syrian hamster as a new model for anxiety testing. Soc. Neuroscience. 2008.
  44. GANNON, RL. How can the output of clock genes be changed pharmacologically? Insitut de Recherches Servier, Versailles, Frances 2009.
  45. GANNON, RL, *Lungwitz, EA, *Batista, N, Millan, MJ. Metabotropic mGluR5 antagonists positively modulate light-induced phase shifts of hamster circadian activity rhythms. Trans. Soc. Neuroscience, 2009 (on CD).   * undergraduate students
  46. GANNON, RL, Millan, MJ. Muscarinic M4 positive allosteric modulation of circadian activity rhythms. International Behavioral Neuroscience Society, 2012
  47. GANNON, RL., Darden, M.  Effects of non-peptide oxytocin receptor agonists and antagonists on hamster circadian activity rhythms.  Basic & Clinical Pharmacology & Toxicology, 115 (Suppl. 1): 189, 2014.