Relationship between cholinergic amacrine cell and development of direction-selective ganglion cell dendritic field in mouse retina

Objective To investigate the growth of retinal direction-selective ganglion cell’s dendritic field (DF) and it’s relationship with cholinergic amacrine mosaic. Methods Thirty six clean YFP (H) strains of transgenic mice were selected from the Laboratory Animal Center of Institute of Biophysics, Chinese Academy of Sciences. They were 0-1 month old, male and female.We compared the numbers of cholinergic amacrine cells within dendritic field of ON/OFF DSGC and OFF DGGC at several postnatal stages(P8, P13 and adulthood ) in mouse retina. Results As a classical directional selective ganglion cell, the dendrites of ON/OFF DSGC have two layers of dendritic structure. They are distributed in the ON and OFF sublayers of reticular layer in the retina. The angle between the curvature of the dendrites and the branches of the dendrites is relatively large. The branches return in the direction of the multidirectional cell bodies in a semi circular pattern. The prominent feature is the dendrites of the same cell. There will be no crossover. At P8, cholinergic amacrine cells in the DF range of D2 subclass ganglion cells contained (25.6±4.8) inner nuclear layers and (28.4±5.7) retinal ganglion cells respectively; at P13, cholinergic amacrine cells and (35.2±1.0) cholinergic amacrine cells in the DF range of D2 subclass ganglion cells contained (30.8±9.5) INL, respectively. (35.2±10.4) cholinergic amacrine cells of GCL; in adulthood, the DF range of D2 subclass ganglion cells contained (33.7±7.4) cholinergic amacrine cells of INL and (32.1±5.6) cholinergic amacrine cells of GCL, respectively. There was no significant difference in the number of cholinergic amacrine cells between the three periods (F=2.16, 1.55; P>0.05). In the DF range of OFF DSGC, the number of amacrine cells increased from P8 to P13, then decreased from P13 to adulthood. At P8, the number of amacrine cells in the DF range of GCL was (20.0±2.5), which was significantly less than that at P13 (32.0±7.1). In adulthood, the number decreased to (23.7±7.5). There was no significant difference in the number of cholinergic amacrine cells between the three periods (F=6.19, 1.55; P<0.05). Conclusions Our results indicated that ON/OFF DSGC achieved mature dendritic field size at very early postnatal stage which highly depended on cholinergic amacrine mosaic but was not influenced by bipolar cells input and light stimulation. While OFF DSGC likely involved different cellular and molecular mechanism. Key words: Dendritic field(DF); Direction-selective ganglion cell(DSGC); Cholinergic amacrine cell