Figure 1.

In vivo hCG IP administration protects the brain from the neurodegenerative effects of HI in a time-dependent manner. (A) The relative tissue losses [calculated by the percent difference between left (L) ipsilateral, ischemic, and right (R) contralateral, non-ischemic, hemisphere] in the hippocampus, striatum and cerebral cortex 7 days after carotid ligation followed by 45 min of hypoxia from NS-injected vs. hCG-injected (1,500 IU/kg) P7 mouse pups treated 15 h prior to HI. hCG treatment decreased hippocampal (NS 44.5 ± 3.9% vs. hCG 28.5 ± 3.8%) and striatal (NS 23.5 ± 3.1% vs. hCG 16.7 ± 2.3%) tissue loss following HI. Actual area values (average ± SEM mm²) in left vs. right hippocampus are 1.8 ± 0.12 vs. 0.97 ± 0.10 mm² for NS and 1.8 ± 0.14 vs. 1.3 ± 0.10 mm² for hCG. Average area values in left vs. right striatum are 3.3 ± 0.19 vs. 2.4 ± 0.12 mm² for NS and 3.0 ± 0.16 vs. 2.5 ± 0.12 mm² for hCG. (B) Representative coronal digital micrographs taken from injured NS- and hCG-injected animals treated 15 h prior to HI. Note the ex-vacuo dilatation of the left, ischemic, cerebral ventricle, and relative atrophy of the left hippocampal formation in the NS group compared with the contralateral brain. (C,D) IP injection of hCG (1,500 IU/kg) 1 h (C) or immediately after (D) neonatal injury in P7 neonatal pups did not protect against the neurodegenerative effects of HI. Error bars show SE; *p < 0.05 and **p < 0.01. hCG, human chorionic gonadotropin; HI, hypoxia-ischemia; Hipp, hippocampus; IP, intraperitoneal; NS, normal saline; Str, striatum.