Neurophysiology and Behavior

Karen Simonyan

Head of Laboratory

PhD

E-mail: karensimonyan@physiol.sci.am E-mail: karensimonyanphysiol@gmail.com

The Laboratory of Neurophysiology and Behavior investigates the neurophysiological mechanisms underlying neurodegenerative pathologies to discover novel therapeutic strategies aimed at preserving neural circuit integrity. By integrating in vivo electrophysiology with comprehensive behavioral profiling, our research maps the functional trajectories of neural networks from early pathogenesis to therapeutic rescue. Our primary research programs interrogate the network-level alterations that drive memory and motor decline, utilizing benchmark experimental models to characterize these pathophysiological states. Within our Alzheimer's disease program, we investigate the progressive disruption of synaptic plasticity and memory consolidation in amyloid-driven models, focusing on aberrant signaling pathways within the hippocampus, the entorhinal cortex, and the amygdala. Concurrently, our investigation into Parkinson's disease deconstructs circuit-level dysfunction using the rotenone model, with a specific emphasis on arresting neurodegeneration across interconnected memory, motor, and modulatory centers, including the hippocampus, substantia nigra, striatum, ventral tegmental area, and the pedunculopontine nucleus. To establish direct correlates between these circuit dynamics and functional outcomes, we couple in vivo electrophysiology with a rigorous behavioral testing matrix assessing cognitive, exploratory, and motor faculties. This comprehensive testing suite leverages Y-maze and T-maze paradigms to evaluate spatial working memory, open-field exploration metrics to characterize exploratory and anxiety-related behaviors, and quantitative cylinder and catalepsy assays to measure motor asymmetry, postural immobility, and neurological deficits. We actively partner with the H. Buniatian Institute of Biochemistry, the G. Davtyan Institute of Hydroponics Problems, and the A.B. Nalbandyan Institute of Chemical Physics.

Publications

1. Darbinyan LV, Hambardzumyan LE, Manukyan LP, Danielyan MH, Karapetyan KV, Sarkisian VH, Simonyan KV. Curcumin treatment reduces motor impairments and protects against rotenone-induced neurodegeneration in a rat model of Parkinson disease. Metab Brain Dis. 2025, 40(7):267. doi: 10.1007/s11011-025-01698-4.

2. Simonyan RM, Babayan MA, Yekmalyan HH, Simonyan SG, Papazyan KT, Stepanyan SA, Sarkavagyan HK, Simonyan GM, Darbinyan LV, Simonyan KV, Chailyan SG, Simonyan MA. Thermostable enzyme isoforms, continuously producing monocomponent superoxide radicals, from human postoperative serous fluids: isolation and properties. BMC Cancer. 2025, 25(1):1555. doi: 10.1186/s12885-025-14372-w.

3. Simonyan K, Darbinyan L, Hambardzumyan L, Manukyan L, Chavushyan V. Teucrium Polium ameliorates amyloid β-induced brain network disorders in rats: electrophysiological and behavioral studies. BMC Complement Med Ther. 2025, 25(1):116. doi: 10.1186/s12906-024-04715-8.

4. Sarkisyan SH, Danielyan MH, Darbinyan LV, Simonyan KV, Chavushyan VA. The effects of vibration on the neuronal activity of lateral vestibular nuclei in unilaterally labyrinthectomized rats. Brain Struct Funct. 2023, 228:463–473. doi: 10.1007/s00429-022-02588-6.

5. Simonyan RM, Simonyan KV, Simonyan GM, Khachatryan HS, Babayan MA, Danielyan MH, Darbinyan LV, Simonyan MA. Superoxide-producing thermostable associate from the small intestines of control and alloxan-induced diabetic rats: quantitative and qualitative changes. BMC Endocr Disord. 2022; 22(1):250. doi: 10.1186/s12902-022-01160-x.

6. Darbinyan LV, Simonyan KV, Hambardzumyan LE, Manukyan LP, Badalyan SH, Sarkisian VH. Protective effect of curcumin against rotenone-induced substantia nigra pars compacta neuronal dysfunction. Metab Brain Dis. 2022 Apr; 37(4):1111-1118. doi: 10.1007/s11011-022-00941-6.

7. Simonyan K, Avetisyan L, Isoyan A, Chavushyan V. Plasticity in Motoneurons Following Spinal Cord Injury in Fructose-induced Diabetic Rats. J Mol Neurosci. 2022 Apr; 72(4):888-899. doi: 10.1007/s12031-021-01958-9.

8. Chavushyan V, Soghomonyan A, Karapetyan G, Simonyan K, Yenkoyan K. Disruption of Cholinergic Circuits as an Area for Targeted Drug Treatment of Alzheimer's Disease: In Vivo Assessment of Short-Term Plasticity in Rat Brain. Pharmaceuticals (Basel). 2020 Oct 9; 13(10):297. doi: 10.3390/ph13100297.

9. Darbinyan LV, Hambardzumyan LE, Simonyan KV, Chavushyan VA, Manukyan LP, Badalyan SA, Khalaji N, Sarkisian VH. Protective effects of curcumin against rotenone-induced rat model of Parkinson's disease: in vivo electrophysiological and behavioral study. Metab Brain Dis. 2017 Dec; 32(6):1791-1803. doi: 10.1007/s11011-017-0060-y.

10. Darbinyan LV, Hambardzumyan LE, Simonyan KV, Chavushyan VA, Manukyan LP, Sarkisian VH. Rotenone impairs hippocampal neuronal activity in a rat model of Parkinson's disease. Pathophysiology. 2017; 24(1):23-30. doi: 10.1016/j.pathophys.2017.01.001.