AGE CHANGES OF BIOELECTRIC ACTIVITY OF MOTOR AND VISUAL CORTEX OF THE RATS BRAIN

Mizin V. V., Lyashenko V. P., Lukashov S. M.

CLINICAL AND EXPERIMENTAL MEDICINE

Scentific article

Age-related changes occur in all systems of the body, especially in the central nervous system. Special attention should be paid to the changes in the bioelectrical activity of the different zones of the neocortex. Most researchers in their studies consider the electrical activity of the cerebral cortex in the early stages of ontogenesis, leaving out the later age periods. But after the complete physiological and functional maturation of the cerebral cortex, the process of age-related changes continues, which should be taken into account when investigating various negative factors. The aim of the work was to establish the age-related changes in the bioelectrical activity of the motor and visual zones of the cerebral cortex of rats of different ages. The experiments were performed on the white non-linear non-native male rats. The rats were divided into 4 groups by age: І group – males of juvenile age of the immature period, (n = 15); ІІ group – males of young age of the reproductive period, (n = 14); ІІІ group – males of mature age of the reproductive period (n = 14); IV group – males of pre-rudimentary age of the period of senile changes, (n = 14). The registration of the electrocorticogram was carried out by removing the stereotaxic potential on a standard electrophysiological device. A needle unipolar electrode (nichrome, diameter 100 μm) was used. In the total amount of the electrocorticogram, the absolute and normalized indicators of electrical activity of the neocortex were analyzed. Having analyzed the absolute power parameters of the motor zone of the cerebral cortex, an age-related decrease in the delta rhythm was observed. Among the rats of young and mature age, the absolute power of delta rhythm decreased by 78% and 88% relative to juvenile males. In pre-teen age, it increased by 60,5% relative to young males. The delta rhythm dominated in the motor zone of the neocortex, except for the rats of young age, where the betalike activity predominated. Accurately high value of the absolute power for all the rhythms of the motor zone was among the males of the juvenile age, and significantly lower – among the rats of mature age. In the visual zone of the neocortex, the power of all the rhythms was two times lower relative to the power indices of the motor cortex of the cerebral cortex. The absolute power indicator of the theta rhythm is reliably lower relative to the other rhythms and has wavy age changes. The index of the alpha-like rhythm in young and mature age is significantly lower – in 2,7 and 13,6 times relative to the juvenile group. Synchronization of rhythms in juvenile, mature and pre-old age was observed according to normalized indices. Among the young rats, desynchronization of rhythms was observed due to an increase in the high-frequency betalike rhythm of the total electrocorticogram. In the visual zone of the neocortex among the rats of the juvenile age, the ratio between low- and high-frequency waves is equal. Synchronization of rhythms was observed in adulthood. Desynchronization of rhythms was observed at young and prescient ages due to an increase in beta-like and alphalike activity. Thus, despite the morphological features of the motor and visual cortex of the brain, the energy resources of neuronal activity decreased with age.

electrocorticogram, motor cortex, visual cortex, juvenile age, young age, mature age, prehistoric age

1. Olsen GM, Witter MP. Posterior parietal cortex of the rat: Architectural delineation and thalamic differentiation. Journal of comparative neurology. 2016;524(18):3774-809. DOI: 10.1002/cne.24032
2. Kudelina OM, Maklyakova YS, Khloponin DP, Matukhno AYe, Gantsgorn YeV. Analiz EEG krys pri vvedenii fluoksetina i yego kombinatsiy s melatoninom. Biomeditsina. 2012;1:93-8. [in Russiаn].
3. Makhmudova NSh. Bioelektricheskiy profil’ zritel’noy i sensomotornoy oblastey kory mozga krys razlichnogo vozrasta, plodnyy period beremennosti proshedshikh v usloviyakh gipokenezii. Sibirskiy meditsinskiy zhurnal. 2013;3:36-8. [in Russiаn].
4. Griffen TC, Haley MS, Fontanini A, Maffei A. Rapid plasticity of visually evoked responses in rat monocular visual cortex. PLOS One. 2017;12(9). DOI: 10.1371/journal.pone.0184618
5. Berchenko OH, Bevzyuk DO, Levicheva NO, Kolyadko SP. Neyrofiziolohichni mekhanizmy formyrovanye nekhimichnoyi zalezhnosti same stimulyatsiyeyu pozytyvno emotsiynikh zon mozkom u shchuriv. Visnyk Dnipropetrovsʹkoho universytetu. Biolohiya, ekolohiya. 2016;24(2):270DOI: 10.15421 / 011634. [in Ukrainian].
6. Murzin OB, Lyashenko VP, Zadorozhna HO. Zminy bioelektrychnoyi aktyvnosti kory holovnoho mozku shchuriv, pid vplyvom vykhrovoho impulʹsnoho mahnitnoho polya. Visnyk problem biolohiyi i medytsyny. 2015;2(118):377-81. [in Ukrainian].
7. Shumilova TE, Smirnov AG, Shereshkov VI, Fedorova MA, Nozdrachev AD. Electrical activity and circulatory effects of nitrite in the rat cerebrum. Biology Bulletin. 2015;42(2):139-44.
8. Zapadnyuk IP, Zapadnyuk VI, Zakhariya YeA, Zapadnyuk BV. Laboratornyye zhivotnyye. Kiyev: Vishcha shkola; 1983. 383 s. [in Russiаn].
9. Paxinos G, Watson C. The rat brain in stereotaxic coordinates. 5-th edition. New York: Akademic Press; 2005: 367 p.
10. Bachinskaya NY. Sindrom umerennykh kognitivnykh narusheniy. NeyroNews: psikhonevrologiya i neyropsikhiatriya. 2010;2(1):12-7. [in Russiаn].
11. Man’kovskiy NB, Kuznetsova SM. Vozrastnyye izmeneniya neyrotransmiternykh sistem mozga kak faktor riska tserebrovaskulyarnoy patologii. Zhurnal nevrologii im. B.M. Man’kovskogo. 2013;2:5-13. [in Russiаn].
12. Schliebs R, Arendt T. The cholinergic system in aging and neuronal degeneration. Behavioural Brain Research. 2011;221:555-63.
13. Mongillo G, Loewenstein Y. Neuroscience: Formation of a Percept in the Rat Cortex. Current Biology. 2017;27(11):423-5. DOI: 10.1016/j. cub.2017. 04.019
14. Obermayer J, Verhovy MB, Luchicchi A, Mansvelder HD. Cholinineryic Modulation of Cortical Microcircuits is Layer-Specific: Evidence from Rodent, Monkey and Human Brain. Front Neural Circuits. 2017;11(100). DOI: 10.3389/fncir.2017.00100
15. Pirttimaki TM, Sims RE, Saunders G, Antonio SA, Codadu NK, Parriet HR. Astrocyte-Mediated Neuronal Sychronization Properties Revealed by False Gliotransmitter Release. Journal of Neuroscience. 2017;11/37(41):2761-16. DOI: 10.1523/JNEUROSCI.2761-16.2017
16. Bradshaw SE, Agster VL, Waterhouse BD, McGauyhy JA. Age-related changes in prefrontal nonepinephrive transporter density: The basis for improved cognitive flexibility after low closes of atomoxetine in adolescent rats. Brain Research. 2016;1641(B):245-57. DOI: 10.1016/j. brainres.2016. 01.001
17. Howe WM, Gritton HJ, Lusk NA, Roberts EA, Hetrick VL, Berke JD, et al. Acetylcholine Release in Prefrontal Cortex Promotes Gamma Oscillations and Theta-Gamma Coupling during Cue Detection. Journal of Neuroscience. 2017;37(12):3215-30

«Bulletin of problems biology and medicine» Issue 2 (144), 2018 year, 197-201 pages, index UDK 612.825:612.66

10.29254/2077-4214-2018-2-144-197-201