Development and localisation of GABAA receptor alfa1, alfa2, beta2 and gama2 subunit mRNAs in the chick optic tectum.

DIEGO J RODRIGUEZ GIL; MARINA VACOTTO; MELINA RAPACIOLI; GABRIEL SCICOLONE; VLADIMIR FLORES; SARA FISZER DE PLAZAS

JOURNAL OF NEUROSCIENCE RESEARCH

Wiley-Liss

Lugar: Nueva York.; Año: 2005 vol. 81 p. 469 - 480

0360-4012

An in situ hybridisation technique was used to analyse the spatial and temporal pattern of expression of the mRNA encoding the four GABAA receptor subunits (a1, a2, b2 and g2) in the developing chick optic tectum. As a rule, layers i, layer h and transient cell compartment 3 (TCC3) show the highest levels of expression, specially of a1, a2 and b2 which undergo striking changes as a function of time. Apart from these common features, the global pattern is highly complex and dynamic. Such complexity derives from the fact that each subunit exhibits a characteristically distinct pattern of expression and the temporal evolution of each differs in the different layers of the tectum. The influence of several developmental cell behaviours such as proliferation, neuronal migration, programmed cell death and differentiation must be taken into account to understand pattern complexity and dynamics. Our results suggest that differences in the rate of subunit expression, particularly of a1, a2 and b2, could have significant consequences on the GABAA receptor complex subunit composition along development and on the functional properties of the GABA neurotransmitter system.