- Neurophysiology of Sleep
- Central Mechanisms of Respiration and Breathing Disorders
- Animal Models for Mechanisms of Cognitive Dysfunction in Sleep Apnea
My research interests are focused on the neurophysiology of sleep and sleep related respiratory disorders. Working at the Center for Narcolepsy, Sleep and Health Research I explore the role of pontine structures of the brain in respiratory regulation. The part of this research determines functionally distinct areas and neurotransmitters involved in the regulation of respiration and REM-sleep events within pedunculopontine tegmentum (PPT), which participates in a wide range of state-regulating and behavioral processes.
My particular interest is concentrated on mechanisms of cognitive impairment in sleep apnea syndrome. Sleep related breathing disorders are often associated with cognitive deficits such as impaired attention, reduced working and long-term memory, impaired learning and cognitive flexibility. Cognitive impairments can be worsened by acute apnea exacerbation that occurs regularly in individuals with sleep apnea. In collaboration with Drs David W Carley and Michael Ragozzino, we have established the novel model relating cognitive performance to measures of sleep and breathing. Using neurophysiological, neurochemical and neuropharmacological methods, I investigate how acute apnea exacerbation affects cholinergic signaling in multiple brain regions related to memory and cognitive functions.
- Diploma Summa Cum Laude, Rostov State University, Russia, 1989
- Second Prize, All-Russian Competition of students' research projects in Biology and Medicine, 1989
- Grant, All-Russian program “Automatic systems in Medicine and Biology”, 1997
- Kang D, Ding M, Topchiy I, Shifflett L, Kocsis B. Theta-rhythmic drive between medial septum and hippocampus in slow wave sleep and microarousal: A Granger causality analysis. J Neurophysiol. 2015; 114(5):2797-803.
- Topchiy I, Amodeo D, Ragozzino M, Waxman J, Radulovacki M, Carley DW. Acute Exacerbation of Sleep Apnea by Hyperoxia Impairs Cognitive Flexibility in Brown-Norway Rats, Sleep.2014; 37(11):1851-1861.
- Fink AM, Topchiy I, Ragozzino ME, Amodeo, DA, Waxman JA, Radulovacki M, Carley DW. Brown Norway and Zucker Lean Rats Demonstrate Circadian Variation in Ventilation and Sleep Apnea. Sleep. 2014, 37(4): 715-721.
- Topchiy I, Radulovacki M, Waxman J, Carley DW. Impact of the vagal feedback on cardiorespiratory coupling in anesthetized rats. Resp. Physiol. Neurobiol. 2011, 175(3):375-82.
- Topchiy I, Waxman J, Radulovacki M, Carley DW. Functional topography of respiratory, cardiovascular and pontine-wave responses to glutamate microstimulation of the pedunculopontine egmentum of the rat. Resp. Physiol.Neurobiol. 2010, 173(1):64-70.
- Topchiy, I, Radulovacki M, Waxman J, Carley DW. Cardiorespiratory effects of intertrigeminal area stimulation in vagotomized rats. Brain Research, 2009, 1250:120-129.
- Topchiy IA, Wood RM, Peterson B, Navas JA, Rojas MJ, Rector DM. Conditioned lick behavior and evoked responses using whisker twitches in head restrained rats. Behav Brain Res 2009,197(1):16-23.
- Li S, Topchiy I, Kocsis B. The effect of atropine administered in the medial septum or hippocampus on high and low frequency theta rhythms in the hippocampus of urethane anesthetized rats. Synapse. 2007, 61(6):412-419.
- Kocsis B and Topchiy I. Intermittent coupling between cardiorespiratory oscillations and neuronal discharge in the medulla of freely moving rats. FASEB Journal, 2007, 21:582.45.
- Rector DM, Topchiy IA, Carter KM, Rojas MJ. Local functional state differences between rat cortical columns. Brain Res. 2005, 1047(1):45-55.
- Verbitskii EV, Topchii IA. Habituation of evoked potentials in subjects with high, medium and low levels of anxiety. I.P.Pavlov Journal of Higher Nervous Activity (Zh Vyssh Nerv Deiat Im IP Pavlova).2005, 55(4):514-7.
- Verbitsky EV, Mendzeritsky AM, Kolpakova NF, Topchiy IA, Lysenko AV, Uskova NI, Alperovich D. The neurophysiologic aspects of relationships between behavior and peptides influence on the "sleep-wakefulness" cycle. In: Basic and clinical aspects of the theory of functional systems. Eds. Lazetic B and Sudakov KV, Novi Sad, Yugoslavia, 1998, pp. 133-139.
Impact of sleep apnea exacerbation on brain cholinergic signaling and cognition
R56 HL126876-01A1 Topchiy (PI)
The main objective of the project is to determine how acute apnea exacerbation in a rat model of sponta-neous sleep apnea alters cholinergic signaling in pedunculo-pontine tegmentum (PPT) and to identify the relationships between state-dependent acetylcholine efflux in the PPT and deficits in working memory and cognitive flexibility. Addtionally, we will test the hypothesis that muscarinic cholinergic receptor activity in the PPT influences both apnea exacerbation and cognitive functioning.
Role: Principal Investigator
Neurobiology of sleep apnea in aging
R01 AG016303 Carley (PI)
The major goals of this project are to establish the impact and neural substrate(s) of brainstem phasic events (BPE) characteristic of REM sleep on cardiorespiratory behaviors. The central hypothesis being tested is: BPE represent a perturbation to respiratory pattern control which is greatest during REM sleep, which increases with aging, and which originates in the pedunculo-pontine tegmental nucleus.
Cannabimimetic treatment of sleep-related breathing disorders UICentre (Drug discovery @ UIC) grant Carley (PI)
A pilot study of several cannabimimetic agents for efficacy in a validated animal model of sleep-related breathing disorder.
Mechanisms of cognitive impairment in sleep apnea syndrome: feasibility studies in a novel animal model UIC Chancellor’s Discovery Fund Award: Topchiy, Carley, Ragozzino (PIs)
The major goals of this pilot project is to establish feasibility and determine effects sizes for future larger scale applications aimed at investigation of the mechanisms by which sleep apnea produces cognitive impairment, using a novel animal model system.
Role: Principal investigator