TY - JOUR
T1 - Transient activity induces a long-lasting increase in the excitability of olfactory bulb interneurons
AU - Inoue, Tsuyoshi
AU - Strowbridge, Ben W.
PY - 2008/1
Y1 - 2008/1
N2 - Little is known about the cellular mechanisms that underlie the processing and storage of sensory in the mammalian olfactory system. Here we show that persistent spiking, an activity pattern associated with working memory in other brain regions, can be evoked in the olfactory bulb by stimuli that mimic physiological patterns of synaptic input. We find that brief discharges trigger persistent activity in individual interneurons that receive slow, subthreshold oscillatory input in acute rat olfactory bulb slices. A 2-to 5-Hz oscillatory input, which resembles the synaptic drive that the olfactory bulb receives during sniffing, is required to maintain persistent firing. Persistent activity depends on muscarinic receptor activation and results from interactions between calcium-dependent after-depolarizations and low-threshold Ca spikes in granule cells. Computer simulations suggest that intrinsically generated persistent activity in granule cells can evoke correlated spiking in reciprocally connected mitral cells. The interaction between the intrinsic currents present in reciprocally connected olfactory bulb neurons constitutes a novel mechanism for synchronized firing in subpopulations of neurons during olfactory processing.
AB - Little is known about the cellular mechanisms that underlie the processing and storage of sensory in the mammalian olfactory system. Here we show that persistent spiking, an activity pattern associated with working memory in other brain regions, can be evoked in the olfactory bulb by stimuli that mimic physiological patterns of synaptic input. We find that brief discharges trigger persistent activity in individual interneurons that receive slow, subthreshold oscillatory input in acute rat olfactory bulb slices. A 2-to 5-Hz oscillatory input, which resembles the synaptic drive that the olfactory bulb receives during sniffing, is required to maintain persistent firing. Persistent activity depends on muscarinic receptor activation and results from interactions between calcium-dependent after-depolarizations and low-threshold Ca spikes in granule cells. Computer simulations suggest that intrinsically generated persistent activity in granule cells can evoke correlated spiking in reciprocally connected mitral cells. The interaction between the intrinsic currents present in reciprocally connected olfactory bulb neurons constitutes a novel mechanism for synchronized firing in subpopulations of neurons during olfactory processing.
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U2 - 10.1152/jn.00526.2007
DO - 10.1152/jn.00526.2007
M3 - Article
C2 - 17959743
AN - SCOPUS:38349023409
VL - 99
SP - 187
EP - 199
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
SN - 0022-3077
IS - 1
ER -