Postnatal development of GABAA receptor β1, β2/3, and γ2 immunoreactivity in the rat retina

✍ Scribed by Peter Koulen

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 484 KB
• Volume: 57
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/(sici)1097-4547(19990715)57:2<185::aid-jnr4>3.0.co;2-t

✦ Synopsis

GABA (␥-aminobutyric

acid) is the major inhibitory neurotransmitter in the mammalian central nervous system and plays an important role in neuronal physiology during ontogenesis. The distribution of the ␤ 1 -, ␤ 2/3 -, and ␥ 2 -subunit of the GABA A receptor in the rat retina was studied during postnatal development using immunohistochemical methods. All subunits were found at birth. However, each subunit showed a unique staining pattern with a different local distribution. The immunoreactivity pattern changed during the time course of postnatal development for each of the proteins investigated. A clustered distribution at presumptive synaptic sites as indicated by a punctate staining pattern of the inner plexiform layer was detected as early as the second day of postnatal development. However, diffuse staining of presumptive extrasynaptic sites was found throughout development. The typical adult layering of immunoreactivity into distinctive bands appeared later in development, characteristically in the second postnatal week. The results of the present study suggest that GABA A receptor expression precedes the formation of functional synapses and changes along with cellular differentiation of the rat retina. Developmentally regulated changes in GABA A receptor composition and distribution indicate possible functions for this receptor during retinal ontogeny.