Ai Ramirez

The influence of ocular hypertension on retinal glial cells

We describe the effects of unilateral laser‐induced ocular hypertension (OHT) in the macroglia and microglia of eyes with OHT and their contralateral normotensive untreated eyes. In both eyes, the glia was reactive even though, contrary to OHT‐eyes, no retinal ganglion cell loss or abnormalities in the electroretinogram were found in contralateral eyes. With respect GFAP immunostaining there were differences between contralateral and OHT‐eye. Signs of microglial activation in contralateral and in OHT‐eyes affected all retinal layers, including: morphological changes, migration, increased cell number, upregulation of activation markers and quantification of the area occupied by Iba‐1+ cells and of the arbor area of Iba‐1+ cells. In microglia, MHC‐II upregulation in contralateral eyes was similar to that in OHT‐eyes. By contrast, MHC‐II upregulation in macroglia was observed mainly in astrocytes in contralateral eyes and in Müller cells in OHT‐eyes. Only eyes with OHT had rod‐like microglia and rounded Iba‐1+ CD68+ CD86+ cells. Glial differences between contralateral and OHT‐eyes could help us to understand glaucoma pathophysiology and develop new strategies for treatment.

The human choroid posseses substance P and calcitonine gene-related peptide intrinsic neurons

Purpose To determine the presence of substance P (SP)-and calcitonine gene-related peptide (CGRP) positive intrinsic choroidal neurons (ICNs) in human Methods Nineteen choroidal whole-mounts were processed for indirect immunofluorescence. Antibody to a component of the neuronal cytoskeleton, neurofilament 200 kDa (NF-200), was combined with antibodies to SP and to CGRP (neuropeptides proper to the sensory nervous system). Results The human choroid possesses numerous SP(+) and CGRP(+) ICNs. These neurons were observed in the suprachoroid, both in isolation and forming microganglia. For both types of ICNs studied, neurons were more numerous in the temporal than in the nasal regions. In both locations, SP(+) and CGRP(+) ICNs were more abundant in the central choroid (the choroid underneath the macular area of the retina), with cell density diminishing outwards to the choroidal periphery. There were no appreciable differences between the two populations of ICNs studied in terms of size, morphology or immunostaining characteristics. Conclusion The human choroid contains an abundant population of SP(+) and CGRP(+) ICNs. Given that peripheral sensory innervation could be involved in the regulation of both choroidal blood flow and vascular architecture, the SP(+) and CGRP(+) ICNs described for first time in the present work may be implicated in these mechanisms of vascular regulation