Immunization with a Neural-Derived Peptide Protects the Spinal Cord from Apoptosis after Traumatic Injury

Figure 1

Number of apoptotic cells at the site of injury. Seven days after SC injury. (a) Rostral region 2 mm from injury epicenter. (b) Injury epicenter at T9 spinal cord level. (c) Caudal region 2 mm from injury epicenter. A91 immunization induced a significant reduction in apoptotic cells. *Different from PBS-immunized rats (𝑃<0.001; Student’s 𝑡-test); **Different from PBS-immunized rats (𝑃<0.0001; Student’s 𝑡-test). Bars represent the mean ± SD of 6 rats. DAPI stain micrograph depicting apoptosis as chromatin condensation and fragmentation of the injury epicenter at 7 days after SC injury. (d) Sham-operated animals had an average of 2.7±1 apoptotic cells at the injury site. (e) Animals subjected to SC contusion and posterior immunization with PBS demonstrated an average of 9.17±1.2 apoptotic cells at the epicenter. (f) The experimental group consisting of A91 immunization had 5.3±0.7 apoptotic cells per field. Arrows depict examples of cells undergoing apoptosis identified by chromatin fragmentation, condensation, and appearance of apoptotic bodies seen as small DAPI-stained clusters within the nucleus or extruded from the cell within cytoplasm blebs. Scale bar = 10 μm.