Rapid reportDarbepoetin alfa (Aranesp®) improves recognition memory in adult rats that have sustained bilateral ventral hippocampal lesions as neonates or young adults
Section snippets
Animals and experimental protocols
All procedures were approved by the University Committee on Laboratory Animals and were conducted in accordance with Canadian Council on Animal Care guidelines. All efforts were made to minimize the number of animals used in this study, and every effort was taken to reduce any suffering. On postnatal day 7 (PD7) a group of Long-Evans rats (Charles River, Montreal, PQ, Canada) underwent either bilateral sham surgeries or lesions of the VH as described previously (Powell et al., 2006). On PD21,
Verification of the lesion
Lesions were restricted to the ventral portion of the hippocampus [Fig. 1 indicates the area of the hippocampus damaged by the lesion; adapted from the atlas of Paxinos and Watson (2005)]. Representative Cresyl Violet–stained sections from adult animals that received bilateral VH lesions as either neonates or young-adults are shown in Fig. 2, Fig. 3. Injection of ibotenic acid into the VH of neonatal and young-adult rats produced lesions of comparable size (Fig. 2B and 2D). No obvious damage
Discussion
The goals of this study were to assess NORT performance of adult animals that were VH lesioned either as neonates (PD7) or young adults (PD42), and to determine the effects of darbepoetin alfa on the NORT performance of these animals. We show here that adult nVH animals displayed deficits in recognition memory at delays of 0.5 and 2 h between the choice and sample phases in the NORT. This result is consistent with studies demonstrating working memory deficits in adult rats that have sustained
Acknowledgments
The authors would like to thank Amgen (Thousand Oaks, CA, USA) for supplying Aranesp®. This work was supported in part by a grant from CIHR (MOP-67017).
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