| First Author | Hellier JL | Year | 2010 |
| Journal | Brain Res | Volume | 1358 |
| Pages | 140-50 | PubMed ID | 20713028 |
| Mgi Jnum | J:166638 | Mgi Id | MGI:4848275 |
| Doi | 10.1016/j.brainres.2010.08.027 | Citation | Hellier JL, et al. (2010) Olfactory discrimination varies in mice with different levels of alpha7-nicotinic acetylcholine receptor expression. Brain Res 1358:140-50 |
| abstractText | Previous studies have shown that schizophrenics have decreased expression of alpha7-nicotinic acetylcholine (alpha7) receptors in the hippocampus and other brain regions, paranoid delusions, disorganized speech, deficits in auditory gating (i.e., inability to inhibit neuronal responses to repetitive auditory stimuli), and difficulties in odor discrimination and detection. Here we use mice with decreased alpha7 expression that also show a deficit in auditory gating to determine if these mice have similar deficits in olfaction. In the adult mouse olfactory bulb (OB), alpha7 expression localizes in the glomerular layer; however, the functional role of alpha7 is unknown. We show that inbred mouse strains (i.e., C3H and C57) with varying alpha7 expressions (e.g., alpha7 wild-type [alpha7+/+], alpha7 heterozygous knock-out [alpha7+/-] and alpha7 homozygous knock-out mice [alpha7-/-]) significantly differ in odor discrimination and detection of chemically-related odorant pairs. Using [(125)I] alpha-bungarotoxin (alpha-BGT) autoradiography, alpha7 expression was measured in the OB. As previously demonstrated, alpha-BGT binding was localized to the glomerular layer. Significantly more expression of alpha7 was observed in C57 alpha7+/+ mice compared to C3H alpha7+/+ mice. Furthermore, C57 alpha7+/+ mice were able to detect a significantly lower concentration of an odor in a mixture compared to C3H alpha7+/+ mice. Both C57 and C3H alpha7+/+ mice discriminated between chemically-related odorants sooner than alpha7+/- or alpha7-/- mice. These data suggest that alpha7-nicotinic-receptors contribute strongly to olfactory discrimination and detection in mice and may be one of the mechanisms producing olfactory dysfunction in schizophrenics. |
