Dr Todor Gerdjikov

PhD Queen's University (Canada)

The overall goal of my research is to characterize how the mesolimbic system of the brain encodes cognitive processes and implements motivated behavior. My focus is on exploring how normal functioning of these brain circuits is sustained and what alterations are associated with preclinical models of psychostimulant addiction and psychosis. For example we recently carried out neurophysiological studies aimed at understanding the brain abnormalities underlying the rat phencyclidine model of schizophrenia. I am further interested in fundamental aspects of attention and motivation which may be compromised in these models. We also use viral-based circuit tracing approaches using transgenic rats to characterize how the mesolimbic system underlies attentional processes including vigilance and reward prediction error.

Hayes J, Laursen B, Eneberg E, Kehler J, Rasmussen LK, Langgard M, Bastlund JF, Gerdjikov TV (2021) Phosphodiesterase type 1 inhibition alters medial prefrontal cortical activity during goal-driven behaviour and partially reverses neurophysiological deficits in the rat phencyclidine model of schizophrenia. Neuropharmacology, 108454.

Talbot S, Gerdjikov T, de Lillo C (2021) Two Variations and One Similarity in Memory Functions Deployed by Mice and Humans to Support Foraging. Quarterly Journal of Experimental Psychology.  doi: 10.1177/17470218211010576

Dautan D, Huerta-Ocampo I, Gut NK, Valencia M, Kondabolu K, Kim Y, Gerdjikov TV,  Mena-Segovia J. (2020) Cholinergic midbrain afferents modulate striatal circuits and shape encoding of action strategies. Nature Communications 11:1-9. doi: 10.1038/s41467-020-15514-3

Stubbendorff C, Molano‐Mazon M, Young AM, Gerdjikov TV (2019) Synchronization in the prefrontal–striatal circuit tracks behavioural choice in a go–no‐go task in rats. European Journal of Neuroscience 49:701-11. doi: 10.1111/ejn.13905

Richard R, Young AMJ, Gerdjikov TV (2018) Cortical local field potential power is associated with behavioral detection of near-threshold stimuli in the rat whisker system: dissociation between orbitofrontal and somatosensory cortices. Journal of Cognitive Neuroscience. 30:42-49. doi: 10.1162/jocn_a_01187

Gerdjikov TV, Bergner C, Schwarz C (2017) Global coding in rat barrel cortex in the absence of local cues. Cerebral Cortex. doi: 10.1093/cercor/bhx108.

Saund J, Dautan D, Rostron C, Urcelay GP, Gerdjikov TV (2017) Thalamic inputs to dorsomedial striatum are involved in inhibitory control: evidence from the 5-choice serial reaction time task in rats. Psychopharmacology. doi: 10.1007/s00213-017-4627-4

Asif-Malik A, Young AMJ, Gerdjikov TV (2017) Changes in cortico-accumbal network activity after phencyclidine pre-treatment: Clues to neurophysiological dysfunction in a rat model of schizophrenia. Brain Structure and Function DOI 10.1007/s00429-017-1393-3

Dautan D, Souza A, Huerta-Ocampo I, Valencia M, Assous M, Witten IB, Deisseroth K, Tepper J, Bolam P, Gerdjikov TV, Mena-Segovia J (2016) Segregated cholinergic transmission in the ventral tegmental area. Nature Neuroscience 19: 1025-1033

Dautan D, Souza A, Huerta I, Valencia M, Witten IB, Deisseroth K, Bolam JP, Gerdjikov TV, Mena-Segovia J (2016) Segregated cholinergic transmission in the ventral tegmental area. Frontiers in Neuroanatomy 10:1.

Young AMJ, Stubbendorff C, Ustárroz MV, Gerdjikov TV (2015) Prefrontal neurophysiological deficits in the phencyclidine model of schizophrenia. Neuroscience. 287:157-63.

Dautan D, Huerta-Ocampo I, Witten IB, Deisseroth K, Bolam JP, Gerdjikov T, Mena-Segovia J. (2014) A major external source of cholinergic innervation of the striatum and nucleus accumbens originates in the brainstem. Journal of Neuroscience. 34:4509-18.

Gerdjikov TV, Haiss F, Rodriguez-Sierra O, Schwarz C (2013). Representation of explorative whisking in rat motor cortex rhythmic whisking area (RW) Journal of Neuroscience. 33:14193-204.

Hawking TH, Gerdjikov TV (2013) Populations of medium spiny neurons encode vibrotactile frequency in rats: modulation by slow wave oscillations. Journal of Neurophysiology. 109:315-20.

Gerdjikov TV, Baker T, Beninger RJ (2011) Amphetamine-induced enhancement of responding for conditioned reward: interactions with repeated testing. Psychopharmacology 214:891-9.

Schwarz C Hentschke H, Butovas S, Haiss F, Stüttgen MC, Gerdjikov TV, Bergner CG, Waiblinger C (2010) The head-fixed behaving rat – procedures and pitfalls. Somatosensory and Motor Research 27:131-48.

Gerdjikov TV, Bergner CG, Stüttgen MC, Waiblinger C, Schwarz C (2010) Discrimination of vibrotactile stimuli in the rat whisker system – behavior and neurometrics. Neuron 65:530-540.

Gerdjikov TV, Rudolph U, Keist R, Mohler H, Feldon J, Yee BK (2008) Hippocampal alpha5 subunit-containing GABA(A) receptors are involved in the development of the latent inhibition effect. Neurobiol Learn Mem 89:87-94.

Harmon-Jones E, Gerdjikov TV, Harmon-Jones, C. (2008) The effect of induced compliance on relative left frontal cortical activity: a test of the action-based model of dissonance. European Journal of Social Psychology 38:35-45.

Gerdjikov TV, Giles AC, Swain SN, Beninger RJ (2007) Nucleus accumbens PKA inhibition blocks acquisition but enhances expression of amphetamine-produced conditioned activity in rats. Psychopharmacology (Berl) 190:65-72.

Gerdjikov TV, Beninger RJ (2006) Place preference induced by nucleus accumbens amphetamine is impaired by local blockade of Group II metabotropic glutamate receptors in rats. BMC Neurosci 7:43.

Gerdjikov TV, Beninger RJ (2005) Differential effects of calcineurin inhibition and protein kinase A activation on nucleus accumbens amphetamine-produced conditioned place preference in rats. Eur J Neurosci 22:697-705.

Beninger RJ, Gerdjikov TV (2005) Dopamine-glutamate interactions in reward-related incentive learning. In: Dopamine and Glutamate in Psychiatric Disorders (Schmidt WJ, Reith EAR, eds.), pp 315-350. Totowa NJ: Humana Press Inc.

Beninger RJ, Gerdjikov T (2004) The role of signaling molecules in reward-related incentive learning. Neurotox Res 6:91-104.

Gerdjikov TV, Ross GM, Beninger RJ (2004) Place preference induced by nucleus accumbens amphetamine is impaired by antagonists of ERK or p38 MAP kinases in rats. Behav Neurosci 118:740-750.

preclinical models of neuropsychiatric disorders

Behavioral Neuroscience
Behavioral Statistics and Research Methods
Current Topics in Cognitive Neuroscience
Psychopharmacology