MODIFICATION IN THE POST-SYNAPTIC DENSITIES ULTRASTRUCTURE AFTER PERINATAL ASPHYXIA IN RAT CENTRAL NERVOUS SYSTEM.

CEBRAL, E. ; CAPANI, F. ; SELVIN-TESTA, A. ; LOIDL, C. F.

Congreso; Annual Meeting of Society for Neuroscience; 2002

Perinatal asphyxia (PA) causes delayed cell death in selected populations of neurons in rat central nervous system. Previously we have demonstrated that neostriatal neurons exhibit delayed neuronal death at 2 months after PA induction in rats (Capani et al, 1997). Post-synaptic density (PSDs) alterations have been before reported neuronal death during an ischemic episode. Using selective staining with ethanolic phosphotungstic acid (E-PTA) and electron microscopic analysis we studied the PSDs modification after 2 months in different time of PA. Rats brains subjected to 5-20 minutes of PA were stained with E-PTA and examined by transmission electron microscopy. PSDs exhibited a marked thickening in the neostriatum of 60-day-old rats that have been subjected to 10-20 minutes of PA. No alterations were seen after 5 min of PA. PSDs were noticeably thicker in tissue subjected to PA than in controls. A study of the time course showed that the increase in PSDs thickness started at 10 minutes of PA (123% of the control values) and continued to increase up to 20 minutes of PA (190% of the control values). We conclude that PSDs in neostriatum are markedly modified. Furthermore these results suggest that this type of synaptic alterations are persistant and may contribute to some of the long-lasting neurological impairments observed during PA.