Effect of Clozapine and 5-NT2A-Antagonist RU-31 on electroencephalography and Motor Activity of Rats in a Model of Schizophrenia with Neonatal Destruction of the Ventral Hippocampus

Background. Schizophrenia is a socially signifi cant disease that takes a variety of forms. The form of the course determines prescribing antipsychotic drugs with a different range of clinical effects. The study of the pharmacological activity of neuroleptics involves an experimental model using animals which makes it possible to reproduce some aspects of schizophrenia.

Objectives. The study is aimed at evaluating the antipsychotic activity of 5-HT2A— RU-31 antagonist and atypical neuroleptic clozapine in behavioral tests and electroencephalography (EEG).

Methods. The research methodology involved a dysontogenetic model of schizophrenia, implemented via aspiration destruction of the ventral hippocampus of rats on day 7 of postnatal development. The study was carried out on white outbred male rats selected from the offspring of females, represented by a simple random sample, provided by Rappolovo animal breeding facility of the National Research Center “Kurchatov Institute”. Injection of the studied substances was initiated on day 35 of postnatal development. Motor activity was assessed on day 54 of postnatal development in the Open Field unit and included assessing vertical motor activity, measured as the number of acts of verticalization in 5 minutes, and horizontal motor activity of rats, recorded as the number of crossed squares in 5 minutes. EEG signals were recorded on day 55 of postnatal development; thereafter the spectral density was calculated in the delta- (д) (0.4–4 Hz), theta- (и) (4.8–8 Hz), alpha- (б) (8–12 Hz) and beta- (в) (12–30 Hz) frequency ranges and the effect of the “operation” and “substance” factors on spectral density was evaluated in comparison with control groups. Statistical data processing was performed using GraphPad Prism 9 (Insight Partners, USA).

Results. The antipsychotic activity of 1-(2-diethylaminoethyl)-2-(4-methoxyphenyl)-imidazo[1,2-a] benzimidazole — RU-31 compound with 5-HT2A-antagonistic mechanism of action was evaluated. RU-31 compound (10 mg/kg, intraperitoneally (i.p.)) statistically signifi cantly reduced vertical and horizontal spontaneous locomotor activity in rats with psychotic disorder by 18.8% and 20.9%, while the atypical neuroleptic clozapine (2 mg/kg, i.p.) signifi cantly reduced these values by 41.15% and 27.67%, respectively. The 5-HT2A-receptor antagonist RU-31 increased EEG signal power in the delta range by 123.33% and decreased it in the alpha range by 41.86% in surgically operated animals (p < 0.05). Clozapine increased the EEG signal power in all studied frequency ranges: in delta — by 107.99%, theta — by 97.16%, alpha — by 41.86% and in beta — by 49.16% in animals with neonatal destruction of the ventral hippocampus (p < 0.05).

Conclusion. The studied substances contributed to the correction of behavioural disturbances associated with hypermobility as well as electrophysiological changes induced by a surgical operation, while similar activity was not observed (or was observed to a lesser extent) in healthy animals.

1. Marder S.R., Cannon T.D. Schizophrenia. N. Engl. J. Med. 2019; 381(18): 1753–1761. DOI: 10.1056/NEJMra1808803

2. McCutcheon R.A., Reis Marques T., Howes O.D. Schizophrenia-An Overview. JAMA Psychiatry. 2020; 77(2): 201–210. DOI: 10.1001/jamapsychiatry.2019.3360

3. Amato D., Vernon A.C., Papaleo F. Dopamine, the antipsychotic molecule: A perspective on mechanisms underlying antipsychotic response variability. Neurosci. Biobehav. Rev. 2018; 85: 146–159. DOI: 10.1016/j.neubiorev.2017.09.027

4. Solmi M., Murru A., Pacchiarotti I., Undurraga J., Veronese N., Fornaro M., Stubbs B., Monaco F., Vieta E., Seeman M.V., Correll C.U., Carvalho A.F. Safety, tolerability, and risks associated with first- and second-generation antipsychotics: a state-of-the-art clinical review. Ther. Clin. Risk. Manag. 2017; 13: 757–777. DOI: 10.2147/TCRM.S117321

5. Grinchii D., Dremencov E. Mechanism of Action of Atypical Antipsychotic Drugs in Mood Disorders. Int. J. Mol. Sci. 2020; 21(24): 9532. DOI: 10.3390/ijms21249532

6. Xu H., Zhuang X. Atypical antipsychotics-induced metabolic syndrome and nonalcoholic fatty liver disease: a critical review. Neuropsychiatr. Dis. Treat. 2019; 15: 2087–2099. DOI: 10.2147/NDT.S208061

7. Grajales D., Ferreira V., Valverde Б.M. Second-Generation Antipsychotics and Dysregulation of Glucose Metabolism: Beyond Weight Gain. Cells. 2019; 8(11): 1336. DOI: 10.3390/cells8111336

8. Kalitin K.Y., Spasov A.A., Mukha O.Y., Pridvorov G.V., Lipatov V.A. Pharmacological targets and the mechanism of action of antipsychotic agents in the framework of the neurochemical theory of the pathogenesis of schizophrenia. Russian Journal of Physiology. 2021; 107(8): 927–954 (In Russ., English abstract). DOI: 10.31857/S0869813921080070

9. Sultanova К.Т., Yakovlev D.S., Maltsev D.V., Miroshnikov М.V., Мorkovina Y.V., Anisimova V.А., Morkovnik A.S. Anхiolytical properties of compound RU-31. Journal of Volgograd State Medical University. 2018; 3(67): 28–32 (In Russ., English abstract). DOI: 10.19163/1994-9480-2018-3(67)-28-32

10. Yakovlev D.S., Naumenko L.V., Sultanova K.T., Spasov A.A. Hemorheological properties of the 5-HT2A-antagonist of the 2-methoxyphenyl-imidazobenzimidazole derivative of the RU-31 compound and cyproheptadine, in comparison with penthoxyphylline. Pharmacy & Pharmacology. 2020; 8(5): 345–353 (In Russ., English abstract). DOI: 10.19163/2307-9266-2020-8-5-345-353

11. Burstein E.S. Relevance of 5-HT2A Receptor Modulation of Pyramidal Cell Excitability for Dementia-Related Psychosis: Implications for Pharmacotherapy. CNS Drugs. 2021; 35(7): 727–741. DOI: 10.1007/s40263-021-00836-7

12. Brisch R., Saniotis A., Wolf R., Bielau H., Bernstein H.G., Steiner J., Bogerts B., Braun K., Jankowski Z., Kumaratilake J., Henneberg M., Gos T. The role of dopamine in schizophrenia from a neurobiological and evolutionary perspective: old fashioned, but still in vogue. Front. Psychiatry. 2014; 5: 47. DOI: 10.3389/fpsyt.2014.00047

13. Becker A. Modeling schizophrenia: focus on developmental models. In Vivo Neuropharmacology and Neurophysiology. 2016; 369–388. DOI: 10.1007/978-1-4939-6490-1_16

14. Amiri S., Dizaji R., Momeny M., Gauvin E., Hosseini M.J. Clozapine attenuates mitochondrial dysfunction, inflammatory gene expression, and behavioral abnormalities in an animal model of schizophrenia. Neuropharmacology. 2021; 187: 108503. DOI: 10.1016/j.neuropharm.2021.108503

15. Ilg A.K., Enkel T., Bartsch D., Bдhner F. Behavioral Effects of Acute Systemic Low-Dose Clozapine in WildType Rats: Implications for the Use of DREADDs in Behavioral Neuroscience. Front. Behav. Neurosci. 2018; 12: 173. DOI: 10.3389/fnbeh.2018.00173

16. Agatsarskaya Ya.V., Yakovlev D.S., Maltsev D.V., Semenova Yu. V., Salikhov D.A., Sultanova K.T., Anisimova V.A. Neuroreceptorological effects of antimigraine agent 9-diethyl-2-(4-methoxyphenyl)imidazo[1,2-a] benzimidazol. Journal of Volgograd State Medical University. 2019; 1(69): 120–124 (In Russ., English abstract). DOI: 10.19163/1994-9480-2019-1(69)-120-124

17. Mitazaki S., Nakagawasai O., Onogi H., Watanabe K., Takahashi K., Tan-No K., Quirion R., Srivastava L.K., Tadano T. Role of prefrontal cortical 5-HT2A receptors and serotonin transporter in the behavioral deficits in post-pubertal rats following neonatal lesion of the ventral hippocampus. Behav. Brain. Res. 2020; 377: 112226. DOI: 10.1016/j.bbr.2019.112226

18. Mitrakova D.O., Chernikov M.V., Spasov A.A., Morkovnik A.S., Remezova I.P., Bunyatyan N.D., Morozov A.V., Divaeva L.N., Zhukovskaya O.N. Preparation, analysis and study of the acute toxicity of 9-(2-diethylaminoethyl)-2-phenylimidazo[1,2-б]benzimidazole dinitrate. Khimiko-Farmatsevticheskii Zhurnal. 2021; 55(6): 16–22. DOI: 10.30906/0023-1134-2021-55-6-16-22

19. Meltzer H.Y., Gadaleta E. Contrasting Typical and Atypical Antipsychotic Drugs. Focus (Am. Psychiatr. Publ). 2021; 19(1): 3–13. DOI: 10.1176/appi.focus.20200051

20. Maleninska K., Jandourkova P., Brozka H., Stuchlik A., Nekovarova T. Selective impairment of timing in a NMDA hypofunction animal model of psychosis. Behav. Brain. Res. 2022; 419: 113671. DOI: 10.1016/j.bbr.2021.113671

21. Yakovlev O.A., Vakhviyaynen M.S., Yudin M.A. Pharmaco-EEG as a Method for Determining the Threshold Dose of Neurotropic Substances. Journal Biomed. 2020; 16(3): 39–42 (In Russ., English abstract). DOI: 10.33647/2074-5982-16-3-39-42

22. Delgado-Sallent C., Nebot P., Gener T., Fath A.B., Timplalexi M., Puig M.V. Atypical, but Not Typical, Antipsychotic Drugs Reduce Hypersynchronized Prefrontal-Hippocampal Circuits during Psychosis-Like States in Mice: Contribution of 5-HT2A and 5-HT1A Receptors. Cereb. Cortex. 2022; 32(16): 3472–3487. DOI: 10.1093/cercor/bhab427

23. Miladinović Đ., Muheim C., Bauer S., Spinnler A., Noain D., Bandarabadi M., Gallusser B., Krummenacher G., Baumann C., Adamantidis A., Brown S.A., Buhmann J.M. SPINDLE: End-to-end learning from EEG/EMG to extrapolate animal sleep scoring across experimental settings, labs and species. PLoS Comput. Biol. 2019; 15(4): e1006968. DOI: 10.1371/journal.pcbi.1006968