What are the neurochemical and behavioral effects of hyperglycemia?
We are also investigating the neurochemical mechanisms that underlie the memory-enhancing and –impairing effects of glucose. Our research indicates that glucose does not affect memory through a non-specific mechanism, such as hyperosmolarity (Shah & Parent, 2003, 2004). Rather, glucose appears to enhance or impair memory through interactions with specific neurotransmitters in different brain regions. For example, we have shown that elevating glucose in the septum creates memory deficits when septal GABA receptors are activated (Parent et al. 1997; Parent & Gold, 1997; Shah & Parent, 2003; Erickson, Watts, & Parent, 2006). In contrast, elevating glucose in the hippocampus prevents memory deficits (Parent et al., 1997; Krebs & Parent, 2005a, 2007), and this enhancing effect of glucose appears to be mediated, at least in part through an interaction with the neurotransmitter acetylcholine (Degroot et al., 2003; Parent & Baxter, 2004).
