TY - JOUR
T1 - Disynaptic amplification of metabotropic glutamate receptor 1 responses in the olfactory bulb
AU - De Saint Jan, Didier
AU - Westbrook, Gary L.
PY - 2007/1/3
Y1 - 2007/1/3
N2 - Sensory systems often respond to rapid stimuli with high frequency and fidelity, as perhaps best exemplified in the auditory system. Fast synaptic responses are fundamental requirements to achieve this task. The importance of speed is less clear in the olfactory system. Moreover, olfactory bulb output mitral cells respond to a single stimulation of the sensory afferents with unusually long EPSPs, lasting several seconds. We examined the temporal characteristics, developmental regulation, and the mechanism generating these responses in mouse olfactory bulb slices. The slow EPSP appeared at postnatal days 10-11 and was mediated by metabotropic glutamate receptor 1 (mGluR1) and NMDA receptors. mGluR1 contribution was unexpected because its activation usually requires strong, high-frequency stimulation of inputs. However, dendritic release of glutamate from the intraglomerular network caused spillover-mediated recurrent activation of metabotropic glutamate receptors. We suggest that persistent responses in mitral cells amplify the incoming sensory information and, along with asynchronous inputs, drive odor-evoked slow temporal activity in the bulb.
AB - Sensory systems often respond to rapid stimuli with high frequency and fidelity, as perhaps best exemplified in the auditory system. Fast synaptic responses are fundamental requirements to achieve this task. The importance of speed is less clear in the olfactory system. Moreover, olfactory bulb output mitral cells respond to a single stimulation of the sensory afferents with unusually long EPSPs, lasting several seconds. We examined the temporal characteristics, developmental regulation, and the mechanism generating these responses in mouse olfactory bulb slices. The slow EPSP appeared at postnatal days 10-11 and was mediated by metabotropic glutamate receptor 1 (mGluR1) and NMDA receptors. mGluR1 contribution was unexpected because its activation usually requires strong, high-frequency stimulation of inputs. However, dendritic release of glutamate from the intraglomerular network caused spillover-mediated recurrent activation of metabotropic glutamate receptors. We suggest that persistent responses in mitral cells amplify the incoming sensory information and, along with asynchronous inputs, drive odor-evoked slow temporal activity in the bulb.
KW - Glomerulus
KW - Glutamate spillover
KW - Mitral cell
KW - Olfactory bulb
KW - Synaptic transmission
KW - mGluR
UR - http://www.scopus.com/inward/record.url?scp=33846132270&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33846132270&partnerID=8YFLogxK
U2 - 10.1523/JNEUROSCI.2439-06.2007
DO - 10.1523/JNEUROSCI.2439-06.2007
M3 - Article
C2 - 17202480
AN - SCOPUS:33846132270
SN - 0270-6474
VL - 27
SP - 132
EP - 140
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 1
ER -