Fragile X mental retardation protein regulates olfactory sensitivity but not odorant discrimination.
Fragile X syndrome (FXS) is the most common cause of inherited intellectual disability and is characterized by cognitive impairments and altered sensory function. It is caused by absence of fragile X mental retardation protein (FMRP), an RNA-binding protein essential for normal synaptic plasticity and function. Animal models have provided important insights into mechanisms through which loss of FMRP impacts cognitive and sensory development and function. While FMRP is highly enriched in the developing and adult olfactory bulb (OB), its role in olfactory sensory function remains poorly understood. Here, we used a mouse model of FXS, the fmr1 (-/y) mouse, to test whether loss of FMRP impacts olfactory discrimination, habituation, or sensitivity using a spontaneous olfactory cross-habituation task at a range of odorant concentrations. We demonstrated that fmr1 (-/y) mice have a significant decrease in olfactory sensitivity compared with wild type controls. When we controlled for differences in sensitivity, we found no effect of loss of FMRP on the ability to habituate to or spontaneously discriminate between odorants. These data indicate that loss of FMRP significantly alters olfactory sensitivity, but not other facets of basal olfactory function. These findings have important implications for future studies aimed at understanding the role of FMRP on sensory functioning.
Department of Neuroscience, Brown University, 185 Meeting Street, Providence, RI 02912, USA.
Arielle
A
Schilit Nitenson
Department of Neuroscience, Brown University, 185 Meeting Street, Providence, RI 02912, USA.
Emily E
EE
Stackpole
Department of Neuroscience, Brown University, 185 Meeting Street, Providence, RI 02912, USA.
Torrey L S
TL
Truszkowski
Universitie Claude Bernard Lyon, Universite de Lyon, Lyon, France.
Maellie
M
Midroit
Department of Neuroscience, Brown University, 185 Meeting Street, Providence, RI 02912, USA.
Justin R
JR
Fallon
Department of Neuroscience, Brown University, 185 Meeting Street, Providence, RI 02912, USA, Department of Cognitive, Linguistic and Psychological Sciences, Brown University, 190 Thayer Street, Providence, RI 02912, USA kevin_bath@brown.edu.
Kevin G
KG
Bath
D000818:Animals; D004195:Disease Models, Animal; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics / Q000378:metabolism*; D005600:Fragile X Syndrome / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009812:Odorants; D009833:Olfactory Pathways / Q000378:metabolism*; D055696:Olfactory Perception / Q000502:physiology*
D051860:Fragile X Messenger Ribonucleoprotein 1
FMRP; behavior; discrimination; mouse; olfaction; sensitivity