Our research group studies normal adult anatomy and the
developmental anatomy of human and monkey retina. One goal is to understand how the complex topography of adult foveate retina is generated during
development. We compare the temporal and spatial expression patterns of marker molecules confined to single neuronal or glial
populations to determine possible developmental interactions within a single population or between populations. We have found a complex
developmental pattern which is characteristic of each photoreceptor type. Although rod photoreceptors become postmitotic well after red,
green and blue cone photoreceptors in the same location, rod opsin protein is found shortly before blue opsin and both are found well before
red or green opsin. In contrast, all cones make synapses long before rods form synapses. The significance of these developmental patterns is
currently being tested using molecular probes to determine factors causing the organization of the primate photoreceptor mosaic.
Another
goal is to determine the developmental pattern of inner retinal circuits which serve each type of photoreceptor. Cell and molecular
markers as well as electron microscopy and cell injection methods are being used to trace specific neuronal circuits in the adult and
fetal retina. We plan to use invitro recording of whole retinas to test physiologically the function of these
circuits.
References
Hendrickson, A. (1994) Primate foveal development: a microcosm of current questions in neurobiology.
Invest. Ophth. Vis.Sci. 35:3129-3133
Dorn EM, Hendrickson LE and Hendrickson AE (1995) The appearance of rod opsin during monkey retinal
development. Invst. Ophth. Vis. Sci. 36:2634-2651
Robinson SR and Hendrickson A (1995) Shifting relationships between
photoreceptors and pigment epithelial cells in monkey retina: implications for the development of retinal topography. Vis. Neurosci.12:
767-778, 1995
Crooks J, Okada M and Hendrickson AE (1995) Quantitative analysis of synaptogenesis in the inner plexiform layer of macaque
monkey fovea. J. Comp. Neurol. 360: 2349-2362.
Hendrickson AE (1996) Synaptic development in macaque monkey retina and its
implications for other developmental sequences. Perspectives in Developmental Neurobiology 3:`195-203
