POSTNATAL DEVELOPMENT OF GABAERGIC NEURONS IN RAT CEREBELLUM

Abstract

Objective - to evaluate the dynamics of the formation of GABAergic neurons in the cortex and nuclei of the developing cerebellum in albino rat postnatal ontogenesis by immunohistochemical detection of glutamate decarboxylase (GAD). Method. The study was performed on 16 outbred albino rats on the 2nd, 7th, 15th day (early postnatal period) and 45th day after birth (puberty). For immunohistochemical detection of GABAergic neurons, primary monoclonal mouse antibodies GAD-67 raised against GAD, an enzyme for the synthesis of gamma-aminobutyric acid, were used. GAD immunoreactivity was studied on paraffin sections of the paravermal zone of the cerebellum. Results. In the cytoplasm of the cell bodies of all types of GABAergic neurons in the cerebellar cortex, GAD was detected as early as on the second postnatal day. In the cytoplasm of the cell bodies of Purkinje cells (PC) it reached the maximum on the 7th day, and in their dendrites - on 15th day, and then decreased; in Golgi cells, maximal GAD staining intensity was detected on 45th day. By the 45th day, in the axons of stellate and basket cells, GAD immunoreactivity became significantly higher; they formed plexuses (baskets) around the PC bodies. GABAergic synapses were detected in the cerebellar cortex on the 7th day and reached their maximal development on the 45th day after birth. Moderate GAD immunoreactivity was detected in the cytoplasm of the cell bodies of neurons in the globose and emboliform nuclei of two-day-old rats. On the 7th day, GAD immunopositive fibers and axodendritic synapses between the neurons, and axosomatic synapses were detected, the number of which increased by the 45th day. Conclusions. GAD immunohistochemical study demonstrates a distinct dynamics of postnatal structural transformations of bodies, processes and synaptic terminals of GABAergic neurons in rat cerebellum.

Keywords

rat cerebellum / postnatal development / GABAergic neurons / glutamate decarboxylase

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RIGHTS & PERMISSIONS

Zimatkin S.M., Karniushko O.A.