The amygdala is a limbic structure that is involved in many brain functions, including emotion, learning and memory. It has been reported that melanopsin-expressing retinal ganglion cells(ip RGCs) innervate the medial...The amygdala is a limbic structure that is involved in many brain functions, including emotion, learning and memory. It has been reported that melanopsin-expressing retinal ganglion cells(ip RGCs) innervate the medial amygdala(Me A). However, whether conventional RGCs(c RGCs) project to the Me A remains unknown. The goal of this study was to determine if c RGCs project to the Me A and to determine the morphological properties of Me A-projecting RGCs(Me A-RGCs). Retrogradely labeled RGCs in whole-mount retinas were intracellularly injected to reveal their dendritic morphologies. Immunohistochemical staining was performed to selectively label ip RGCs(Me A-ip RGCs) and c RGCs(Me A-c RGCs). The results showed that 95.7% of the retrogradely labeled cells were c RGCs and that the rest were ip RGCs. Specifically, Me A-c RGCs consist of two morphological types. The majority of them exhibit small but dense dendritic fields and diffuse ramification patterns as previously reported in RG_(B2)(95%), while the rest exhibit small but sparse dendritic branching patterns resembling those of RG_(B3) cells(5%). Me Aip RGCs consist of M1 and M2 subtypes. The Me A-RGCs showed an even retinal distribution patterns. The soma and dendritic field sizes of the Me A-RGCs did not vary with eccentricity. In conclusion, the present results suggest that Me A-RGCs are structurally heterogeneous. These direct RGCs that input to the Me A could be important for regulating amygdala functions.展开更多
基金supported by the National Nature Science Foundation of China(81401102 to Liju Luan)National Nature Science Foundation of China(31571091 to Mingliang Pu)the National Basic Research Program of China(2016CB351806 to Mingliang Pu)
文摘The amygdala is a limbic structure that is involved in many brain functions, including emotion, learning and memory. It has been reported that melanopsin-expressing retinal ganglion cells(ip RGCs) innervate the medial amygdala(Me A). However, whether conventional RGCs(c RGCs) project to the Me A remains unknown. The goal of this study was to determine if c RGCs project to the Me A and to determine the morphological properties of Me A-projecting RGCs(Me A-RGCs). Retrogradely labeled RGCs in whole-mount retinas were intracellularly injected to reveal their dendritic morphologies. Immunohistochemical staining was performed to selectively label ip RGCs(Me A-ip RGCs) and c RGCs(Me A-c RGCs). The results showed that 95.7% of the retrogradely labeled cells were c RGCs and that the rest were ip RGCs. Specifically, Me A-c RGCs consist of two morphological types. The majority of them exhibit small but dense dendritic fields and diffuse ramification patterns as previously reported in RG_(B2)(95%), while the rest exhibit small but sparse dendritic branching patterns resembling those of RG_(B3) cells(5%). Me Aip RGCs consist of M1 and M2 subtypes. The Me A-RGCs showed an even retinal distribution patterns. The soma and dendritic field sizes of the Me A-RGCs did not vary with eccentricity. In conclusion, the present results suggest that Me A-RGCs are structurally heterogeneous. These direct RGCs that input to the Me A could be important for regulating amygdala functions.
