Anesthesia & Clinical Research
Open Access

Abstract

Isoflurane Exposure did not Adversely Affect Recognition Memory or Decrease Hippocampal Brain Derived Neurotrophic Factor Expression in the 17 Day Old Rat Pup

Michelle E Schober, Benjamin Block, Daniela F Requena, Merica A Hale and Robert H Lane

A previous study showed that hippocampal BDNF mRNA decreased in 17 day old (D17) rats, relative to agematched naïve rats, at day 1, 3, 7 and 14 after sham surgery in a traumatic brain injury model. The anesthetic isoflurane activates GABA and inhibits NMDA receptor currents, both of which are known to decrease Brain-Derived Neurotrophic Factor (BDNF) mRNA in rat hippocampi. Hippocampal BDNF is necessary for normal cognitive function. Effects of isoflurane alone on hippocampal BDNF are not known. We hypothesized that, in D17 rat pups, isoflurane would decrease hippocampal mRNA/protein levels of BDNF and Synapsin I (a downstream target of BDNF important for cognitive function) and impair performance on the Novel Object Recognition Test (NOR). ISOF BDNF and Synapsin I mRNA decreased relative to Naïve at day 1 and 8 after exposure, but not at day 14. Isoflurane exposure did not decrease hippocampal protein levels of BDNF or Synapsin I and did not impair NOR performance. In contrast to the neonatal rat pup, anesthetic exposure did not impair cognitive function. We speculate that adverse effects of anesthetics on rat pup cognitive function and BDNF expression are highly dependent on age at exposure.