I’m constantly on the lookout for new research findings further substantiating sleep’s significant effects on memory…perhaps in an attempt to finally convince myself that continuously misplacing my keys is NOT a normal part of young adulthood…and that 5 hours of shut-eye just isn’t cutting it anymore (note to self: resist late night treks to Starbucks).
Coffee-drinking women on the other hand have an 18% lower chance of having visual and spatial memory declines according to a 2007 study by Ritchie et. al. “No relation was found between caffeine intake and cognitive decline in men”…NOT FAIR!
a link on How to Overcome a Starbucks Addiction
Anyway…a recent study by Girardeau et al. found online at Nature Neuroscience once again confirms sleep’s important function on memory consolidation. They found that suppressing sharp wave-ripple (SPW-R) complexes in the hippocampus-entorhinal cortex of rats during post-training rest and sleep significantly impaired spatial memory (I’d bet that we’d see similar effects by suppressing slow-wave sleep spindles in the thalamus as well).
The authors suggest that SPW-Rs play a crucial role in spatial memory consolidation by temporarily compressing reactivations of waking firing sequences thus allowing activation of NMDA receptors and spike time-dependent plasticity.
You may be wondering at this point if there’s anything you can do to avoid the risk of spatial memory loss other than getting good sleep. Well you’re in luck according to 2008 study conducted by Ron-Harel and colleagues. They found that functional cell-mediated immunity was necessary for the maintenance of hippocampus-dependent spatial memory in mice. In other words, the healthier the mice the better the spatial memory.
So remember kids, rest up and stay healthy or you might literally lose your marbles.
More about the origin of “losing your marbles” found here.
Ritchie, K., Carriere, I., de Mendonca, A., Portet, F., Dartigues, J., Rouaud, O., Barberger-Gateau, P., & Ancelin, M. (2007). The neuroprotective effects of caffeine: A prospective population study (the Three City Study) Neurology, 69 (6), 536-545 DOI: 10.1212/01.wnl.0000266670.35219.0c
Girardeau1,G, Benchenane1, K, Wiener, S I, Buzsáki G, & Zugaro1, M B. (2009). Selective suppression of hippocampal ripples impairs spatial memory.Nature Neuroscience : 10.1038/nn.2384
Ron-Harel N, Segev Y, Lewitus GM, Cardon M, Ziv Y, Netanely D, Jacob-Hirsch J, Amariglio N, Rechavi G, Domany E, & Schwartz M (2008). Age-dependent spatial memory loss can be partially restored by immune activation. Rejuvenation research, 11 (5), 903-13 PMID: 18803478