AIM: To investigate the morphology and electrophysiological properties of neurons in the inner nuclear layer(INL)of the adult rat retina slices. The retinal slices were prepared by low-melt agarose embedding and then cutted by vibratome.

METHODS: Whole cell patch clamp and intracellular staining with Lucifer Yellow were used in this study to study the morphology and electrophysiological properties of the INL neurons in retinal slices.

RESULTS: Retinal slices prepared in this method possessed a very smooth surface. The cells on the retinal slices maitained very good vitality, and some of the cells even retained their dendritic connections with other cells on the slice. According to the size and location of the cell bodies, neurons in the INL were easy to differentiate. Luciifer Yellow contained in the intracellular solution revealed the morphology of the recorded cell very well. Bipolar cells possessed elongated cell bodies and their processes mainly extended along the vertical direction. Horizontal cells and amacrine cells possessed much bigger and round cell bodies, resided in the outermost and inner most of the INL, respectively. The rest membrane potential and membrane capacitance of horizontal cell and amacrine cell were much higher than that of bipolar cells. Under a voltage step from -60mV to +40mV, 10mV per step, 41.7% of the cone bipolar cells and 64.7% of the amacrine cells exhibited inward sodium current and outward potassium current. Other cells only possessed outward potassium current.

CONCLUSION: The method of preparing retinal slices was very simple, and the viability of the slices were stable. These facilitated the patch-clamp recording of all the neurons in the INL including horizontal cells. Further investigation of the electrophysiological properties of the neurons in the INL was essential in revealing the mechanism of vision.